Post on 25-Mar-2018
1
WCDMA FDD Mode Transmitter
Dr Chih-Peng Li (李志鵬)
2
Table of ContentsTraditional Sequential ASIC Design FlowIntroduction to WCDMA Transmitter Specifications
WCDMA Network ArchitecturePhysical Layer General DescriptionMultiplexing and Channel Coding (MCC)WCDMA Uplink Physical LayerWCDMA Downlink Physical Layer
3
References
3GPP Technical Specification (Release 1999 25 Series)WCDMA for UMTS ndash Radio Access For Third Generation Mobile Communications
-- by Harri Holma and Antti Toskala Artech House 2001
Wireless Communications - Principles amp Practice-- by Theodore S Rappaport Prentice Hall 2nd Edition Dec 31 2001
4
Traditional Sequential ASIC Design Flow
5
Traditional Sequential ASIC Design FlowSpecification
System ModelsArchitecture Design
RTL Design
Logic synthesis
Physical Design
RTL Design
Functional Verification
Logical Synthesis
Timing Verification
P amp R
Physical Verification
Prototype Build amp Test Prototype
6
WCDMA Network Architecture
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
2
Table of ContentsTraditional Sequential ASIC Design FlowIntroduction to WCDMA Transmitter Specifications
WCDMA Network ArchitecturePhysical Layer General DescriptionMultiplexing and Channel Coding (MCC)WCDMA Uplink Physical LayerWCDMA Downlink Physical Layer
3
References
3GPP Technical Specification (Release 1999 25 Series)WCDMA for UMTS ndash Radio Access For Third Generation Mobile Communications
-- by Harri Holma and Antti Toskala Artech House 2001
Wireless Communications - Principles amp Practice-- by Theodore S Rappaport Prentice Hall 2nd Edition Dec 31 2001
4
Traditional Sequential ASIC Design Flow
5
Traditional Sequential ASIC Design FlowSpecification
System ModelsArchitecture Design
RTL Design
Logic synthesis
Physical Design
RTL Design
Functional Verification
Logical Synthesis
Timing Verification
P amp R
Physical Verification
Prototype Build amp Test Prototype
6
WCDMA Network Architecture
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
3
References
3GPP Technical Specification (Release 1999 25 Series)WCDMA for UMTS ndash Radio Access For Third Generation Mobile Communications
-- by Harri Holma and Antti Toskala Artech House 2001
Wireless Communications - Principles amp Practice-- by Theodore S Rappaport Prentice Hall 2nd Edition Dec 31 2001
4
Traditional Sequential ASIC Design Flow
5
Traditional Sequential ASIC Design FlowSpecification
System ModelsArchitecture Design
RTL Design
Logic synthesis
Physical Design
RTL Design
Functional Verification
Logical Synthesis
Timing Verification
P amp R
Physical Verification
Prototype Build amp Test Prototype
6
WCDMA Network Architecture
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
4
Traditional Sequential ASIC Design Flow
5
Traditional Sequential ASIC Design FlowSpecification
System ModelsArchitecture Design
RTL Design
Logic synthesis
Physical Design
RTL Design
Functional Verification
Logical Synthesis
Timing Verification
P amp R
Physical Verification
Prototype Build amp Test Prototype
6
WCDMA Network Architecture
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
5
Traditional Sequential ASIC Design FlowSpecification
System ModelsArchitecture Design
RTL Design
Logic synthesis
Physical Design
RTL Design
Functional Verification
Logical Synthesis
Timing Verification
P amp R
Physical Verification
Prototype Build amp Test Prototype
6
WCDMA Network Architecture
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
6
WCDMA Network Architecture
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
7
Network Elements in a WCDMA PLMNUu Iu
USIM
ME
Cu
UE
Node B
Node B
Node B
Node B
RNC
RNC
Iub Iur
UTRAN
MSCVLR GMSC
SGSN GGSN
HLR
Core Network
PLMN PSTNISDN hellip etc
Internet
ExternalNetworks
bullPLMN Public Land Mobile Network One PLMN is operated by a single operator
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
8
User Equipment (UE)The UE consists of two parts
The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interfaceThe UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity performs authentication algorithms and stores authentication and encryption keys and some subscription information that is needed at the terminal
UTRAN consists of two distinct elementsThe Node B converts the data flow between the Iub and Uuinterfaces It also participates in radio resource managementThe Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it) RNC is the service access point for all services UTRAN provides the core network (CN)
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
9
WCDMA System Architecture
UMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systemsThe network elements are grouped into
The Radio Access Network (RAN UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionalityThe Core Network (CN) which is responsible for switching and routing calls and data connections to external networks
Both User Equipment (UE) and UTRAN consist of completely new protocols which is based on the new WCDMA radio technologyThe definition of CN is adopted from GSM
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
10
Main Elements of the GSM Core Network
HLR (Home Location Register) is a database located in the userrsquos home system that stores the master copy of the userrsquos service profile
The service profile consists of for example information on allowed services forbidden roaming areas and Supplementary Service information such as status of call forwarding and the call forwarding numberIt is created when a new user subscribes to the systemHLR stores the UE location on the level of MSCVLR andor SGSN
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
11
MSCVLR (Mobile Services Switching Center Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services
The MSC function is used to switch the CS transactionsThe VLR function holds a copy of the visiting userrsquos service profile as well as more precise information on the UErsquoslocation within the serving system
Main Elements of the GSM Core Network
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
12
GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks
All incoming and outgoing circuit switched connections go through GMSC
SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSCVLR but is typically used for Packet Switched (PS) servicesGGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services
Main Elements of the GSM Core Network
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
13
InterfacesCu Interface this is the electrical interface between the USIM smartcard and the ME The interface follows a standard format for smartcardsUu Interface this is the WCDMA radio interface which is the subject of the main part of WCDMA technology This is also the most important open interface in UMTSIu Interface this connects UTRAN to the CNIur Interface the open Iur interface allows soft handover between RNCs from different manufacturersIub Interface the Iub connects a Node B and an RNC UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
14
WCDMA Physical Layer General Description (3GPP TS 25201)
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
15
Elements of A Digital Communications System
Information Bits
)(ˆ tsi
Format SourceEncoding Encryption Channel
Encoding Multiplexing Modulation FrequencySpreading
MultipleAccess
TXRFPA
BitStream
DigitalWaveformSynchronization
CHANNEL
Source Bits Channel Bits
Channel BitsSource Bits
)(tsiDigitalInput
im
DigitalOutput
im
Information Sink
From Other Sources
To Other Destinations
Optional
Essential
Interleaving
Format SourceDecoding Decryption Channel
Decoding Demultiplexing Demodulation FrequencyDespreading
MultipleAccess
RXRFIF
Deinterleaving
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
16
Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode and specifies
Transport channelsPhysical channels and their structureRelative timing between different physical
channels in the same link and relative timing between uplink and downlink
Mapping of transport channels onto the physical channels
Physical channels and mapping of transport channels onto physical channels (FDD)
TS 25211
Describes the contents of the layer 1 documents (TS 25200 series) where to find information a general description of layer 1
Physical Layer ndashgeneral description
TS 25201
3GPP (Radio Access Network) RAN Specifications
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
17
Establishes the characteristics of the spreading and modulation in the FDD mode and specifies
SpreadingGeneration of channelization and scrambling codesGeneration of random access preamble codesGeneration of synchronization codesModulation
Spreading and Modulation (FDD)
TS 25213
Describes multiplexing channel coding and interleaving in the FDD mode and specifies
Coding and multiplexing of transport channelsChannel coding alternativesCoding for layer 1 control informationDifferent interleaversRate matchingPhysical channel segmentation and mapping
Multiplexing and Channel Coding (FDD)
TS 25212
3GPP (Radio Access Network) RAN Specifications
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
18
Establishes the characteristics of the physical layer measurements in the FDD mode and specifies
The measurements performance by layer 1Reporting of measurements to higher layers and
networkHandover measurements and idle-mode
measurements
Physical Layer Measurements (FDD)
TS 25215
Establishes the characteristics of the physical layer procedures in the FDD mode and specifies
Cell search proceduresPower control proceduresRandom access procedure
Physical Layer Procedures (FDD)
TS 25214
3GPP (Radio Access Network) RAN Specifications
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
19
General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and networkThe radio interface is composed of Layers 1 2 and 3
Radio Resource Control (RRC)
Medium Access Control
Transport channels
Physical layer
Con
trol
Mea
sure
men
ts
Layer 3
Logical channelsLayer 2
Layer 1
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
20
General Protocol ArchitectureThe circles between different layersub-layers indicate service access points (SAPs)The physical layer offers different transport channels to MAC
A transport channel is characterized by how the information is transferred over the radio interface
MAC offers different logical channels to the radio link control (RLC) sub-layer of Layer 2
A logical channel is characterized by the type of information transferred
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
21
Transport Channels
Transport channels are services offered by Layer 1 to the higher layersA transport channel is defined by how and with what characteristics data is transferred over the air interface
Two groups of transport channelsDedicated Transport Channels
Common Transport Channels
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
22
Transport channelsDedicated Transport Channels
DCH ndash Dedicated Channel (only one type)
Common Transport Channels ndash divided between all or a group of users in a cell (no soft handover but some of them can have fast power control)
BCH Broadcast Channel
FACH Forward Access Channel
PCH Paging Channel
RACH Random Access Channel
CPCH Common Packet Channel
DSCH DL Shared Channel
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
23
Dedicated Transport Channels
There exists only one type of dedicated transport channel the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channelThe DCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDCH carries both the service data such as speech frames and higher layer control information such as handover commands or measurement reports from the terminalPossibility of fast rate change (every 10 ms)Support of fast power control and soft handover
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
24
Common Transport ChannelBroadcast Channel (BCH) -- mandatory
BCH is a downlink transport channel that is used to broadcast system and cell specific informationBCH is always transmitted over the entire cellThe most typical data needed in every network is the available random access codes and access slots in the cell or the types of transmit diversityBCH is transmitted with relatively high powerSingle transport format ndash a low and fixed data rate for the UTRA broadcast channel to support low-end terminals
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
25
Common Transport ChannelPaging Channel (PCH) -- mandatory
PCH is a downlink transport channelPCH is always transmitted over the entire cellPCH carries data relevant to the paging procedure that is when the network wants to initiate communication with the terminalThe identical paging message can be transmitted in a single cell or in up to a few hundreds of cells depending on the system configuration
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
26
Common Transport ChannelRandom Access Channel (RACH) -- mandatory
RACH is an uplink transport channelRACH is intended to be used to carry control information from the terminal such as requests to set up a connectionRACH can also be used to send small amounts of packet data from the terminal to the networkThe RACH is always received from the entire cellThe RACH is characterized by a collision riskRACH is transmitted using open loop power control
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
27
Common Transport ChannelForward Access Channel (FACH) -- mandatory
FACH is a downlink transport channelFACH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasFACH can carry control information for example after a random access message has been received by the base stationFACH can also transmit packet dataFACH does not use fast power controlFACH can be transmitted using slow power controlThere can be more than one FACH in a cellThe messages transmitted need to include in-band identification information
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
28
Common Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH is an uplink transport channelCPCH is an extension to the RACH channel that is intended to carry packet-based user dataCPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (eg Emergency Stop) for the uplink CPCHThe CPCH is characterised by initial collision risk and by being transmitted using inner loop power controlCPCH may last several frames
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
29
Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH is a downlink transport channel shared by several UEsto carry dedicated user data andor control informationThe DSCH is always associated with one or several downlink DCHThe DSCH is transmitted over the entire cell or over only a part of the cell using eg beam-forming antennasDSCH supports fast power control as well as variable bit rate on a frame-by-frame basis
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
30
Mapping of Transport Channels onto Physical Channels
Transport Channels
DCH
RACH
CPCH
BCH
FACH
PCH
Physical Channels
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Physical Random Access Channel (PRACH)
Physical Common Packet Channel (PCPCH)
Primary Common Control Physical Channel (P-CCPCH)
Secondary Common Control Physical Channel (S-CCPCH)
DSCH Physical Downlink Shared Channel (PDSCH)
Common Pilot Channel (CPICH)Synchronization Channel (SCH)
Acquisition Indicator Channel (AICH)
Access Preamble Acquisition Indicator Channel (AP-AICH)
Paging Indicator Channel (PICH)
CPCH Status Indicator Channel (CSICH)
Collision-DetectionChannel-Assignment Indicator Channel
(CDCA-ICH)⎪⎪⎪⎪
⎩
⎪⎪⎪⎪
⎨
⎧
Unmapped
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
31
Multiplexing and Channel Coding( 3GPP TS 25212 )
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
32
UL Multiplexing and Channel Coding
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
33
DL Multiplexing and Channel Coding
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
34
CRC-AttachmentCRC-attachment
For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1
TrBk
TrBk
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
35
Channel CodingUsage of coding scheme and coding rate
No coding13Turbo coding
13 12CPCH DCH DSCH FACH
RACHPCH
12Convolutional codingBCH
Coding rateCoding schemeType of TrCH
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
36
WCDMA Uplink Physical Layer( 3GPP TS 25211 amp 25213 )
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
37
OverviewConfiguration
Radio frameA radio frame is a processing unit which consists of 15 slotsThe length of a radio frame corresponds to 38400 chips
Time slotA time slot is a unit which consists of fields containing bitsThe length of a slot corresponds to 2560 chips
Spreading Modulation QPSKData Modulation BPSKSpreading
Two-level spreading processes
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
38
OverviewSpreading (cont)
Channelization operationOVSF codesTransform every data symbol into a number of chipsIncrease the bandwidth of the signalThe number of chips per data symbol is called the Spreading FactorData symbols on I- and Q-branches are independently multiplied with an OVSF code
Scrambling operationLong or short Gold codesApplied to the spread signalsRandomize the codes
Spread signal is further multiplied by complex-valued scrambling
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
39
Uplink Physical Channels
Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)
Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
40
Dedicated Uplink Physical ChannelsUL Dedicated Physical Data Channel (UL DPDCH)
Carry the DCH transport channel (generated at Layer 2 and above)There may be zero one or several uplink DPDCHs on each radio link
UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
41
Frame Structure for UL DPDCHDPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips 10 bits
1 radio frame Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips
Slot 0 Slot 1 Slot i Slot 14
Ndata= 102k bits (k=01hellip6)
One Power Control Period
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
42
UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slotIt is related to the spreading factor SF of the DPDCH as SF = 2562kThe DPDCH spreading factor ranges from 256 down to 4
640640960049609606
320320480084804805
1601602400162402404
80801200321201203
40406006460602
202030012830301
101015025615150
NdataBits Slot
Bits Frame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
43
UL DPCCH - Layer 1 Control InformationThe spreading factor of the uplink DPCCH is always equal to 256 ie there are 10 bits per uplink DPCCH slot
8-924131015025615155B
10-1423141015025615155A
1522151015025615155
8-1520261015025615154
8-1510271015025615153
8-914231015025615152B
10-1413241015025615152A
1512251015025615152
8-1500281015025615151
8-904241015025615150B
10-1403251015025615150A
1502261015025615150
Transmitted slots per
radio frame
NFBINTFCINTPCNpilotBitsSlot
BitsFrame
SFChannel Symbol Rate
(ksps)
Channel Bit Rate (kbps)
Slot Format i
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
44
UL DPCCH - Layer 1 Control InformationPilot Bits
Support channel estimation for coherent detectionFrame Synchronization Word (FSW) can be sued to confirm frame synchronizaton
Transmit Power Control (TPC) commandInner loop power control commands
Feedback Information (FBI)Support of close loop transmit diversitySite Selection Diversity Transmission (SSDT)
Transport-Format Combination Indicator (TFCI) ndashoptional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
45
Pilot Bit Patterns with Npilot=3456
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
101001101110000
100011110101100
111111111111111
111111111111111
101001101110000
100011110101100
Slot 01234567891011121314
543210432103210210Bit Npilot = 6Npilot = 5Npilot = 4Npilot = 3
Shadowed column is defined as FSW (Frame Synchronization Word)
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
46
Pilot Bit Patterns with Npilot=78
Shadowed column is defined as FSW (Frame Synchronization Word)
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
111111111111111
001010000111011
110001001101011
111111111111111
101001101110000
100011110101100
111111111111111
Slot 0123456789
1011121314
765432106543210Bit Npilot = 8Npilot = 7
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
47
IΣ
j
c d 1 β d
S lo n g n o r S s h o r t n
I+ jQ
D P D C H 1
Q
c d 3 β d
D P D C H 3
c d 5 β d
D P D C H 5
c d 2 β d
D P D C H 2
c d 4 β d
D P D C H 4
c d 6 β d
D P D C H 6
c c β c
D P C C H
Σ
Spreading of UL DPCH
One and only one UL DPCCHUp to six parallel DPDCHs
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
48
Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences ie the binary value 0 is mapped to the real value +1 while the binary value 1 is mapped to the real value ndash1The DPCCH is spread to the chip rate by the channelization code cc while the nth DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cdnOne DPCCH and up to six parallel DPDCHs can be transmitted simultaneously ie 1 le n le 6
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
49
Channelization Codes
Each CDMA channel is distinguished via a unique spreading codeThese spreading codes should have low cross-correlation valuesIn 3GPP W-CDMA orthogonal variable spreading factor (OVSF) codes are usedPreserve the orthogonality between a userrsquos different physical channelsScrambling is used on top of spreading
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
50
Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes
SF = 1 SF = 2 SF = 4
Cch10 = (1)
Cch20 = (11)
Cch21 = (1-1)
Cch40 =(1111)
Cch41 = (11-1-1)
Cch42 = (1-11-1)
Cch43 = (1-1-11)
The channelization codes are uniquely described as CchSFk where SF isthe spreading factor of the code and k is the code number 0 le k le SF-1
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
51
Generation of Channelization Codes1Cch10 =
⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡minus
=⎥⎦
⎤⎢⎣
⎡
1111
01
01
01
01
12
02
ch
ch
ch
ch
ch
ch
CC
CC
CC
( )
( )
( )
( )
( ) ( )
( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minus
minus
minus
=
⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
minusminus
minusminus
minus++
minus++
+
+
+
+
122122
122122
1212
1212
0202
0202
11212
21212
312
212
112
012
nnchnnch
nnchnnch
nchnch
nchnch
nchnch
nchnch
nnch
nnch
nch
nch
nch
nch
CCCC
CCCCCC
CC
CC
CCCC
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
52
OVSF Code Allocation for UL DPCHDPCCH is always spread by cc= Cch2560
When there is only one DPDCHDPDCH1 is spread by cd1= CchSFk (k= SF 4)
When there are more than one DPDCHAll DPDCHs have SF=4
DPDCHn is spread by the the code cdn = Cch4k
k = 1 if n isin 1 2 k = 3 if n isin 3 4 and k = 2 if n isin 5 6
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
53
Gain of UL DPCHAfter channelization the real-valued spread signals are weighted by gain factors βc for DPCCH and βd for all DPDCHsAt every instant in time at least one of the valuesβc andβd has the amplitude 10 The β-values are quantized into 4 bit wordsAfter the weighting the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chipsThis complex-valued signal is then scrambled by the complex-valued scrambling code Sdpchn
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
54
Signaling values for βc and βd
Quantized amplitude ratios βc and βd
15 10 14 09333 13 08666 12 08000 11 07333 10 06667 9 06000 8 05333 7 04667 6 04000 5 03333 4 02667 3 02000 2 01333 1 00667 0 Switch off
Gain of UL DPCH
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
55
Configuration of Uplink Scrambling Sequence Generator
clong1n
clong2n
MSB LSB
x
y
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
56
Uplink Long Scrambling Codes
Two elementary codes clong1n and clong2n
clong1n and clong2n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences x and y
x and y are originated from two generator polynomials of degree 25x sequence generator polynomial X25+X3+1y sequence generator polynomial y25+y3+y2+y+1
The sequence clong2n is a 16777232 chip shifted version of the sequence clong1nclong1n and clong2n are Gold codes
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
57
Uplink Long Scrambling Codes
For code number nn=[n23 hellip n0 ] with n0 being the LSB
Let xn(i) and y(i) denote the i -th chip of the sequence xn and y
Initial conditionsxn(0)=n0 xn(1)=n1 hellip xn(22)=n22 xn(23)=n23 xn(24)=1
y(0)=y(1)= hellip =y(23)= y(24)=1
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
58
Uplink Long Scrambling Codes
Recursive formulation i=0hellip 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2
y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2
Gold sequence zn
zn(i ) = xn(i ) + y (i ) modulo 2 i = 0 1 2 hellip 225-2
22101)(10)(1
)( 25 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
59
Uplink Long Scrambling Codes
clong1n(i ) = Zn(i ) i = 0 1 2 hellip 225-2
clong2n is a 16777232 chip shifted version of the sequence clong1n
clong2n(i ) = Zn((i + 16777232) modulo (225 ndash 1)) i = 0 1 2 hellip 225-2
⎭⎬⎫
⎩⎨⎧
⎥⎦⎥
⎢⎣⎢minus+= )2
2()1(1)()( 21icjiciC nlong
inlongnlong
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
60
Uplink Short Scrambling Sequence Generator for 255 Chip Sequence
07 4
+ mod n addition
d(i)12356
2
mod 2
07 4b(i)
12356
2
mod 2
+mod 4multiplication
zn(i)
07 4 12356
+mod 4
Mapper
cshort1n(i)
a(i)
+ + +
+ ++
+ ++
3 3
3
2
cshort2n(i)
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
61
Uplink Short Scrambling CodesTwo elementary codes cshort1n and cshort2n
256 chips
GenerationFrom the family of periodically extended S(2) codesThe nth quaternary S(2) sequence zn(i ) 0 le n le 16777215 is obtained by modulo 4 addition of three sequences
One quaternary sequence a (i )Two binary sequences b (i ) and d (i )
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
62
Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0 254)Given a code number n =[n23n22hellipn0] quaternary sequence a (i ) g0(x)= x8+x5+3x3+x2+2x+1
Initial conditionsa (0) = 2n0 + 1 modulo 4
a (i) = 2ni modulo 4 i = 1 2 hellip 7
Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4 i = 8 9 hellip 254
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
63
Uplink Short Scrambling CodesBinary sequence b(i) g1(x)= x8+x7+x5+x+1
Initial conditionsB (i ) = n8+i modulo 2 i = 0 1 hellip 7
Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2 i = 8 9 hellip 254
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
64
Uplink Short Scrambling CodesBinary sequence d (i ) g2(x)= x8+x7+x5+x4+1
Initial conditionsd (i ) = n16+i modulo 2 i = 0 1 hellip 7
Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2 i = 8 9 hellip 254
zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0 254)
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
65
Uplink Short Scrambling Codeszn(i) is extended to length 256 chips
zn(255) = zn(0)
Mapping
Cshort n is
zn(i) cshort1n(i) cshort2n(i)0 +1 +11 -1 +12 -1 -13 +1 -1
⎭⎬⎫
⎩⎨⎧
⎟⎠⎞
⎜⎝⎛
⎥⎦⎥
⎢⎣⎢minus+=
2256mod2)1(1)256mod()( 21
icjiciC nshorti
nshortnshort
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
66
Uplink ModulationThe modulation chip rate is 384 McpsThe complex-valued chip sequence generated by the spreading process is QPSK modulated
S
ImS
ReS
cos(ωt)
Complex-valuedchip sequencefrom spreadingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
67
Uplink Transmitter Functional Block
DI
DQ
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
TSprimeTS+
+
+
+
IC
IC
QC
Gain Controlch1C
2561C
DPDCH
DPCCH
tAcos cω
tAsin cω
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
sum
+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
68
WCDMA Downlink Physical Layer( 3GPP TS 25211 amp 25213 )
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
69
Table of Contents
IntroductionDedicated Downlink Physical Channels
Downlink Dedicated Physical Channel (DL DPCH)
Common Downlink Physical ChannelsCommon Pilot Channel (CPICH)
Timing RelationshipSpreadingModulation
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
70
Introduction
Downlink DPCHAICH CPICHCCPCH PICH
IdleMS
On-lineMS
Power-onMS
SCH
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
71
Downlink Transmit DiversityOpen loop transmit diversity STTD and TSTDClosed loop transmit diversity BS
ˇˇ-DL-DPCCH for CPCH
-ˇ-CDCA-ICH
-ˇ-AP-AICH
ndashˇndashCSICH
ndashˇndashAICH
ˇˇndashPDSCH
ndashˇndashPICH
ˇˇndashDPCH
ndashˇndashS-CCPCH
ndashndashˇSCH
ndashˇndashP-CCPCH
ModeSTTDTSTD
Closed loopOpen loop modePhysical channel type
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
72
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
The STTD encoding is optional in UTRAN STTD support is mandatory at the UESTTD encoding is applied on blocks of 4 consecutive channel bits
b 0 b 1 b 2 b 3
b 0 b 1 b 2 b 3
-b 2 b 3 b 0 -b 1
A ntenna 1
A ntenna 2C hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
73
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTDTSTD for the SCH is optional in UTRAN while TSTD support is mandatory in the UEPrim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
Antenna 1
Antenna 2
acsi0
acp
acsi1
acp
acsi14
acp
Slot 0 Slot 1 Slot 14
acsi2
acp
Slot 2
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
74
Closed Loop Mode Transmit Diversity
Spreadscramblew1
w2
DPCHDPCCH
DPDCH
sum
CPICH1
sum
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25214 V390 Sect 7
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
75
The spread complex valued signal is fed to both TX antenna branches and weighted with antenna specific weight factors w1 and w2 where wi = ai + jbi The weight factors (phase adjustments in closed loop mode 1 and phaseamplitude adjustments in closed loop mode 2) are determined by the UE and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCHFor the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas
Closed Loop Mode Transmit Diversity
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
76
Number of Feedback Information in Closed Loop Transmit Diversity
Summary of number of feedback information bits per slot NFBD feedback command length in slots NW feedback command rate feedback bit rate number of phase bits Nph per signalling word number of amplitude bits Npo per signalling word and amount of constellation rotation at UE for the two closed loop modes
NA311500 bps1500 Hz412
π2101500 bps1500 Hz111
Constellation rotation
NphNpoFeedback bit rate
Update rateNWNFBDClosed loop mode
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
77
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
The UE uses the CPICH to separately estimate the channels seen from each antennaOnce every slot the UE computes the phase adjustment φ and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received powerThe UE feeds back to the UTRAN access point the information on which phasepower settings to useFeedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity the FBI D field Each message is of length NW = Npo+Nph bits
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
78
Closed Loop Mode 1
The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received powerIn each slot UE calculates the optimum phase adjustment φ for antenna 2 which is then quantized into having two possible values as follows
where
If = 0 a command 0 is sent to UTRAN using the FSMphfield If = π command 1 is sent to UTRAN using the FSMph field
⎩⎨⎧ leminuslt
=otherwise0
23)(2 if πφφππφ
irQ
⎩⎨⎧
==
=1311975312
141210864200)(
ii
ir πφ
QφQφ
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
79
Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment
02081
08020
Power_ant2Power_ant1FSMpo
3π4100π2101π41110110
-π4010-π2011-3π4001
π000Phase difference between antennas (radians)FSMph
FSMpo subfield ofsignalling message
FSMph subfield ofsignalling message
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
80
Downlink Dedicated Physical Channels (DPCH)
There is only one type of downlink dedicated physical channel the Downlink Dedicated Physical Channel (DL DPCH) Within one downlink DPCH dedicated data generated at Layer 2 and above ie the dedicated transport channel (DCH) is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits TPC commands and an optional TFCI)
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
81
Frame Structure of DL DPCH
One radio frame Tf = 10 ms
TPC NTPC bits
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 102k bits (k=07)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
82
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each slot= 2560 chips
Each slot= one power-control period
SF = 5122k (eg SF=512 256 4)Two basic types
With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)
It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
83
DL DPCH Fields (table is not completed)
8-14442822025615305A
154221022025615305
8-148042444012830604B
8-144021222025615304A
154021222025615304
8-144442444012830603B
8-142421022025615303A
152221222025615303
8-144042844012830602B
8-142021422025615302A
152021422025615302
8-14844402025615301B
15422201051275151
8-14804802025615300B
8-14402401051275150A
15402401051275150
NPilotNTFCINTPCNData2NData1
Transmittedslots per
radio frame NTr
DPCCHBitsSlot
DPDCHBitsSlot
Bits Slot
SFChannelSymbol
Rate (ksps)
ChanneBit Rate(kbps)
SlotFormat i
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
84
DL DPCH Pilot Bit Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
110001001011111001110110100000
Slot 01234567891011121314
765432103210100Symbol
Npilot = 16(3)
Npilot = 8(2)
Npilot = 4(1)
Npilot=2
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
85
DL DPCH Multi-Code Transmission
TransmissionPower Physical Channel 1
TransmissionPower Physical Channel 2
TransmissionPower Physical Channel L
DPDCH
One Slot (2560 chips)
TFCI PilotTPC
bull bull
bull
DPDCH Condition
Total bit rate to be transmitted exceeds the maximum bit rate
Layer 1 control information is transmitted only on the first DL DPCH
Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
86
Common Pilot Channel (CPICH)Frame Structure
Pre-defined symbol sequence
Slot 0 Slot 1 Slot i Slot 14
Tslot = 2560 chips 20 bits = 10 symbols
1 radio frame Tf = 10 ms
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
87
Common Pilot Channel
The CPICH is a fixed rate (30 kbps SF=256) downlink physical channel that carries a pre-defined bitsymbol sequenceIn case transmit diversity (open or closed loop) is used on any downlink channel in the cell the CPICH shall be transmitted from both antennas using the same channelization and scrambling codeThere are two types of Common pilot channels
The Primary CPICHThe Secondary CPICH
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
88
Transmit Diversity of CPICHModulation pattern for Common Pilot Channel (with A = 1+j)
slot 1
Framei+1Framei
slot 14
A A A A A A A A A A A A A A A A A A A A A A A A
-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2
Antenna 1
slot 0
Frame Boundary
In case of no transmit diversity thesymbol sequence of Antenna 1 is used
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
89
The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics
The same channelization code is always used for the P-CPICHThe P-CPICH is scrambled by the primary scrambling codeThere is one and only one P-CPICH per cellThe P-CPICH is broadcast over the entire cell
The Primary CPICH is a phase reference for the following downlink channels SCH Primary CCPCH AICH PICH AP-AICH CDCA-ICH CSICH DL-DPCCH for CPCH and the S-CCPCHBy default the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCHThe Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
90
Secondary Common Pilot Channel(S-CPICH)
A Secondary Common Pilot Channel (S-CPICH) has the following characteristics
An arbitrary channelization code of SF=256 is used for the S-CPICHA S-CPICH is scrambled by either the primary or a secondary scrambling codeThere may be zero one or several S-CPICHs per cellA S-CPICH may be transmitted over the entire cell or only over a part of the cell
A Secondary CPICH may be a phase reference for a downlink DPCHThe Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity instead of the Primary CPICH being a phase reference
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
91
Downlink Phase Reference
ndashndashˇDL-DPCCH for CPCH
ndashndashˇCSICH
ndashndashˇAICH
ˇˇˇPDSCH
ndashndashˇPICH
ˇˇˇDPCH
ndashndashˇS-CCPCH
ndashndashˇSCH
ndashndashˇP-CCPCH
Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type
Note the same phase reference as with the associated DPCH shall be used
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
92
Timing Relationship between Physical Channels
kth S-CCPCH
AICH access slots
Secondary SCH
Primary SCH
τS-CCPCHk
10 ms
τPICH
0 1 2 3 14 13 12 11 10 9 8 7 6 5 4
Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1
τDPCHn
P-CCPCH
Any CPICH
PICH for kth S-CCPCH
Any PDSCH
nth DPCH
10 ms
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
93
Spreading for All Downlink Physical Channels Except Synchronization Channel (SCH)
I
Any downlinkphysical channelexcept SCH
SrarrP
CchSFm
j
Sdln
Q
I+jQ S
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
94
Spreading and Modulation for SCH and P-CCPCH
Different downlink Physical channels (point S in Figure of previous page)
Σ
G1
G2
GP
GS
S-SCH
P-SCH
Σ
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
95
Downlink Scrambling Codes8192 codes are chosen from a total of 218-1 scrambling codes numbered 0hellip262142
These chosen scrambling codes are divided into 512 sets each set has
One primary scrambling codeCode number n=16i (i=0hellip511)
15 secondary scrambling codes Code number n=16i+k (k=1hellip15)
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
96
Downlink Scrambling Codes512 primary scrambling codes
Further divided into 64 scrambling code groups
Each group consisting of 8 primary scrambling codes
The jth scrambling code group consists of primary scrambling codes 168j+16k (j=063 amp k=07)
Each cell is allocated one and only one primary scrambling codeThe primary CCPCH primary CPICH PICH AICH AP-AICH CDCA-ICH CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling codeThe other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
97
Configuration of Downlink Scrambling Code Generator
I
Q
1
1 0
02
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
98
Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences x and y
Generator polynomials is of degree 18
38400 chip segments (10 ms radio frame)
Gold sequences
x sequence generator polynomial 1+X7+X18
Initial x (0)=1 x(1)= x(2)== x (16)= x (17)=0
x(i+18) =x(i+7) + x(i) modulo 2 i=0hellip218-20
y sequence generator polynomial 1+y 5+y 7+ y 10+y 18
Initial y(0)=y(1)= hellip =y(16)= y(17)=1
y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2 i=0hellip 218-20
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
99
Downlink Scrambling Codes
The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2 i=0hellip 218-2
Mapping
The nth complex scrambling code sequence Sdln is defined as
22101)(10)(1
)( 18 minus=⎩⎨⎧
=minus=+
= hellipiforizifizif
iZn
nn
Sdln(i) = Zn(i) + j Zn((i+131072) modulo (218-1)) i=01hellip38399
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
100
Downlink ModulationIn the downlink the complex-valued chip sequence generated by the spreading process is QPSK modulated
T
ImT
ReT
cos(ωt)
Complex-valuedchip sequencefrom summingoperations
-sin(ωt)
Splitreal ampimagparts
Pulse-shaping
Pulse-shaping
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus
101
Downlink Transmitter Functional Block
DI
DQ
jAntipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1 sum
Pulse Shaping
Filter
Pulse Shaping
Filter
sum
Root Nyquistr=022
Root Nyquistr=022
Channel Model
-Complex Gaussian
-MultipathRayleigh
-UMTS Channel
TSprimeTS+
+
+
+
Other User Signals
IC
IC
QC
ch1C
ch1C
DPDCH1DPCCH
Antipodal Conv
ldquo0rdquogt+1 ldquo1rdquogt-1
Gain Control
sum+
minus