Lecture boğaziçi üniversitesi 2016 presentation - offline ping-pong optimized pulse shaping for...

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1 Offline Ping - Pong Optimized Pulse Shaping for Future 5G Systems: POPS - FBMC Mohamed Siala MEDIATRON Laboratory Higher School of Communication of Tunis (SUP’COM) Carthage University - Tunisia Boğaziçi Üniversitesi Beşiktaş /İstanbul - Türkiye May 11, 2016

Transcript of Lecture boğaziçi üniversitesi 2016 presentation - offline ping-pong optimized pulse shaping for...

Page 1: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

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Offline Ping-Pong Optimized Pulse Shaping for

Future 5G Systems: POPS-FBMC

Mohamed Siala

MEDIATRON Laboratory

Higher School of Communication of Tunis (SUP’COM)

Carthage University - Tunisia

Boğaziçi Üniversitesi

Beşiktaş/İstanbul - Türkiye

May 11, 2016

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Outline

Motivation of Research Activities on Pulse Shaping for 5G

OFDM/OFDMA

5G Challenges and Requirements

POPS-OFDM to Systematically Respond to 5G Radio Interface

Challenges

Conclusion and Perspectives for Future Research Work on 5G

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Motivation of Research Activities on Pulse

Shaping for 5G OFDM/OFDMA

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5G Challenges and Requirements 1/2

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5G Challenges and Requirements 2/2

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4G (LTE-A) Pitfalls

LTE is tailored to maximize performance by enforcing strict synchronism and perfect orthogonality

Machine-type communication (MTC) requires bulky procedures to

ensure strict synchronism

Collaborative schemes (e.g. CoMP) use tremendous efforts to

collect gains under strict synchronism and orthogonality

Digital Agenda/Carrier aggregation forces systems to deal with

fragmented spectrum

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Need for Non-Orthogonal Waveforms

Non-orthogonal waveforms on the physical layer will enable:

Asynchronous MTC traffic with drastically reduced signalling and

increased life time

The provision of asynchronous coordinated multi-point (CoMP) /

Heterogeneous Networking (HetNet)

Implementation of asynchronous carrier aggregation concepts with

well frequency localization

A (filtered) multicarrier approach will enable:

The mix of synchronous/asynchronous and orthogonal/non-

orthogonal traffic types

The aggregation of non-contiguous spectrum thanks to low out-of-

band emissions of the non-orthogonal waveforms

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Workload of Current Mobiles

8

Outer receiver consists of channel decoder and de-interleaver

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Projects on 5G

From 2007 to 2013, the European Union set aside €700 million of

funding (FP7) for research on future networks, half of which was

reserved for the development of 4G and beyond-4G technologies.

METIS, 5GNOW, iJOIN, TROPIC, Mobile Cloud Networking,

COMBO, MOTO and PHYLAWS are some of the latest EU research

projects that address the architecture and functionality needs of 5G

networks, representing some €50 million EU investment.

European Union’s FP7 project, PHYDYAS (Duration: 30 months,

Start: January 2008, End: October 2010, Total Cost: 4 093 483€),

investigated Filter Bank Multi-Carrier (FBMC) and corresponding

transceiver functionalities.

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5GNOW Candidate Waveforms

European Union’s FP7 projects, 5GNOW (5th Generation Non-

Orthogonal Waveforms for Asynchronous Signaling), (Start:

September 2012, End: February 2015, Total Cost: 3 526 991 €),

investigated 4 candidate waveforms:

Generalized Frequency Division Multiplexing (GFDM)

Universal Filtered Multicarrier (UFMC)

Filter Bank Multi-Carrier (FBMC)

Bi-orthogonal Frequency Division Multiplexing (BFDM)

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GFDM: Generalized Frequency Division

Multiplexing

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UFMC: Universal Filtered MultiCarrier

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Spectral behavior within a single sub-band

Single PRB compared to OFDM

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5G Challenges and Requirements

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Requirements for 5G: Coordinated MultiPoint

(CoMP)

Joint Processing (JP):

Coordination between multiple BSs

MSs are simultaneously transmitting or receiving to or from

multiple BSs

Coordinated Scheduling/Coordinated Beamforming (CS/CB):

Coordination between multiple BSs

MSs are transmitting or receiving to or from a single transmission

or reception BS

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Requirements for 5G: Coordinated MultiPoint

(CoMP) – Overlapping in Time

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timeAt the BSs

MS2MS1

time

TDOA Overlapping in time

Artificial delay spread

Inter-Symbol Interference

At MS2

time

At MS1TDOA: Time Difference of Arrival

Applicable even for fully

time synchronous BSs

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Requirements for 5G: Coordinated MultiPoint

(CoMP) – Overlapping in Frequency

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MS

frequency

Carrier Frequency Offset Overlapping in frequency Artificial Doppler spread

Inter-Carrier Interference (ICI)

At MS

From BS1

frequency

frequency

From BS2

From BS3Applicable only for non fully

frequency Synchronous BSs

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Requirements for 4G, 5G and DVB-T: MBMS

and SFN 1/2

17Overlapping replicas Artificial delay spread Interference

time

At the BSs/DVB-T TV Station

time

At the TV Set

(SFN)

At the MS

(MBMS)

SFN: Single Frequency

Network

MBMS: Multimedia Broadcast

Multicast Service

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Requirements for 4G, 5G and DVB-T: MBMS

and SFN 2/2

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MBMS: Replicas of the same modulated

signal arriving at different delays at the MS

Delay spread

Aggregate “artificial » delay spread

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Requirements for 5G: Sporadic Traffic and Fast

Dormancy 1/5

2G, 3G and 4G systems continuously transmit reference signals and

broadcast system information that is used by terminals as they move

across cells

The more signaling the cellular standard requires, the more complex

and power-hungry will be the devices

With denser deployment and more network nodes (MTC), such

“always-on” transmissions are not attractive from an interference and

energy consumption perspective

Maximizing the devices’ sleep opportunities, through sporadic

access, minimizes energy consumption, leading to long battery life

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Page 20: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Requirements for 5G: Sporadic Traffic and Fast

Dormancy 2/5

Sporadic access poses a significant challenge to mobile access

networks due to fast dormancy:

Fast dormancy is used to save battery power: The mobile breaks

ties to the network as soon as a data piece is delivered

When the mobile has to deliver more pieces of data it will always

go through the complete synchronization procedure again

This can happen several hundred times a day, resulting in

significant control signaling growth and network congestion threat

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Requirements for 5G: Sporadic Traffic and Fast

Dormancy 3/5

21Nokia Siemens Networks, Understanding Smartphone Behavior in the Network,

White Paper, 2011, [Available: http://www.nokiasiemensnetworks.com/sites/default/files

Comparisons of Data and Signaling Traffic

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Requirements for 5G: Sporadic Traffic and Fast

Dormancy 4/5

It is desirable to achieve “zero-overhead” communications by

providing channel access with minimal signaling

Get rid of closed-loop timing control (which costs energy and

signaling overhead, being undesirable for MTC) and use open loop

timing control mechanisms: The device uses the downlink pilot signals

by the BS for a rough synchronization (RSSI: Received Signal

Strength Indication)

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Requirements for 5G: Sporadic Traffic and Fast

Dormancy 5/5

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Overhead Payload (Useful information)

High data rate service with “always-on” transmission: Overhead << PayloadTime

Overhead Payload (Useful information)

TimeLoss of synchronization

Delayed

transmission

Sporadic access with fast dormancy and no synchronization procedure

Payload (Useful information)

TimeLoss of synchronization

Sporadic access with fast dormancy using a complete synchronization procedure:

Overhead >> Payload

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Requirements for 5G: Sporadic Traffic and Fast

Dormancy – Relaxed Frequency Synchronization

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MS2

Reduced synchronization overhead Relaxed frequency synchronization

Carrier Frequency Offset Overlapping in frequency

Inter-user interference in frequency

From MS1

frequency

MS1MS3

frequencyFrom MS2

frequencyFrom MS3

At BS

frequency

Inter-user interference

Unaligned carrier frequencies

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Requirements for 5G: Sporadic Traffic and Fast

Dormancy – Relaxed Time Synchronization

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MS2

Reduced synchronization overhead Relaxed time synchronization

Overlapping in time

Inter-user interference in time

MS1

From MS1

time

timeFrom MS2

At BS

time

Inter-user interference

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Requirements for 5G: Asynchronous Signaling in

the Uplink – RACH 1/3

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MS2MS1

RACH random access

MS2 experiences a higher round-trip delay than MS1

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Requirements for 5G: Asynchronous Signaling in

the Uplink – RACH 2/3

27

time

No synchronization overhead Strong overlapping in time

Inter-user interference in time

To/from BS

time

To/from MS1

To/from MS2

Inter-Burst interference

time

Synchronization

channel

RACH burst

from MS2

RACH burst

from MS1Propagation

delay to MS1

Propagation

delay to MS2

Page 28: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Requirements for 5G: Asynchronous Signaling in

the Uplink – RACH 3/3

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Use of open loop timing control: The device uses the RSSI for a rough synchronization Shadowing disturbance Partially alleviated

asynchronism

RSSI: Received Signal Strength Indication

Ideal pathloss

Path loss

+ shadowingIdeal arrival at the BS

(No overlapping)

Actual arrival at the BS

(Overlapping in time)

Time

Page 29: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Requirements for 5G: Spectrum Agility and

Carrier Aggregation 1/2

TV White Spaces (TVWS) exploration can represent a new niche

markets if it overcomes, with spectrum agility, the rigorous

implementation requirements of low out-of-band (OOB) radiations for

protection of legacy systems

The LTE-A waveform imposes generous guard bands to satisfy

spectral mask requirements which either severely deteriorate spectral

efficiency or even prevent band usage

5G will address carrier aggregation by implementing non-orthogonal

waveforms, with low OOB emissions, in order not to interfere with

other legacy systems and conform to tight spectral masks

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Requirements for 5G: Spectrum Agility and

Carrier Aggregation 2/2

30

OFDM vs. ESM: Loss of efficiency of traditional OFDM to fit in an ESM

(Emission Spectrum Mask) due to its non-negligible side lobes

55 dB protection

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Requirements for 5G: Low Latency 1/2

4G offers latencies of multiple 10 ms between terminal and BS that

originate from resource scheduling, frame processing, retransmission

procedures, and so on.

The access latency offered by LTE is not sufficient for latency-critical

applications, such as tactile internet (motivated by the tactile sense of

the human body, which can distinguish latencies on the order of 1 ms

accuracy), traffic safety and infrastructure protection.

To ensure support for such mission-critical MTC applications, next-

generation wireless access should allow for latencies on the order of 1

ms or less.

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Page 32: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Requirements for 5G: Low Latency 2/2

A 1 ms round-trip time for a typical tactile interaction requires a time

budget of maximum 100 µs on the physical layer

Far shorter than LTE-A allows, missing the target by nearly two

orders of magnitude

Clear motivation for an innovative and disruptive redesign of

the PHY layer

Lower latency over the radio link can be achieved by reducing

transmission-time intervals and widening the bandwidth of radio

resource blocks in which a specific amount of data is transmitted

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Requirements for 5G: Lower Latency vs Doppler

Spread-Delay Spread Balancing 1/2

33

Time

F

T

Frequency

Doppler shift

Time delayDB

mT

Reduced global ICI+ISI Good balancing between T and F

Increased Latency

ICI

ICI

ISIISI

Processing

Time at the Rx2

mTmin

Contribution of the PHY to the latency

Page 34: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Requirements for 5G: Lower Latency vs Doppler

Spread-Delay Spread Balancing 2/2

34

Time

F

T

Frequency

Doppler shift

Time

delayDB

mT

Decreased Latency

Bad balancing between

T and F

Increased global

ICI+ISI

ISIISI

Processing

Time at the Rx2

mTmin

Contribution of the PHY to the latency

ICI

ICI

Page 35: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

POPS-OFDM to Systematically Respond to 5G

Radio Interface Challenges

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Page 36: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

POPS-OFDM Categories

36

POPS-OFDM

Continuous DiscreteTime

Optimum

exploration space2 ( ) 2 ( )

Practical

exploration space

1

0Vect({ ( )} )N

k kt

1

0Vect({ ( )} )N

k kt

0{ ( )}k kt

0{ ( )}k kt

: Hermite functions

: Prolate Spheroidal Wave Functions (PSWF)

To be explored next

2 ( )I

Page 37: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

33φ32φ31φ30φ

23φ22φ21φ20φ

13φ12φ11φ10φ

OFDM Time-Frequency Lattice: Transmitter

Side

Time

Frequency

Signal

00 φ φ 01φ 02φ 03φ

Time Shift by TTime Shift by 2TTime Shift by 3T

Frequency

Shift by F

Frequency

Shift by 2F

Frequency

Shift by 3F

Symbol Period T

=

Symbol Spacing

Symbol Bandwidth F = Subcarrier Spacing

: Transmitter Prototype Waveformφ

mnφ

Subcarrier Index Symbol Index

Frequency shift of by mF Time shift of by nT37

Page 38: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

30 30a φ

20 20a φ

10 10a φ

00 00a φ

1

0 0

0

Q

m m

m

a

φ

OFDM Transmitted Signal

Time

Frequency

Signal21 21a φ

11 11a φ

01 01a φ

31 31a φ

1

1 1

0

Q

m m

m

a

φ

1

0

: Sampled Version of the Transmitted OFDM SignalQ

mn mn

n m

a

e φ

1

2 2

0

Q

m m

m

a

φ

32 32a φ

22 22a φ

12 12a φ

02 02a φ

1

3 3

0

Q

m m

m

a

φ

33 33a φ

23 23a φ

13 13a φ

03 03a φ

SubcarriersQ

38

Page 39: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Propagation Channel Characteristics: Delay and

Doppler Spreads

Mobile speed

( , )S p

p

dB : Doppler spread

Doppler spread spectrum

: Discrete time delay

: Doppler frequency shift

( , )S p : Channel scattering function

: Discrete time delay spreadmT 39

Page 40: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

30 30a φ

20 20a φ

10 10a φ

00 00a φ

1

0 0

0

Q

m m

m

a

φ

OFDM Received Signal

Time

Frequency

Signal

1

0

: Sampled Version of the Received OFDM SignalQ

mn mn

n m

a

r φ n

21 21a φ

11 11a φ

01 01a φ

31 31a φ

1

1 1

0

Q

m m

m

a

φ

: Additive White Gaussian Noisen

: Channel distorted version of mn mnφ φ

40

ISIICI

Page 41: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Decision variables

: Receiver Prototype Waveform (Vector)ψ

klψ

Subcarrier Index Symbol Index

Frequency shift of by kF Time shift of by lT

H

kl kl ψ r : Decision variable on kla

( , ) ( , )Noise TermUseful Term

Interference Term

H H H

kl kl kl kl mn kl mn kl

m n k l

a a

ψ φ ψ φ ψ n

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Page 42: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Signal-to-Interference and Noise Ratio (SINR)

S

I N

PSINR

P P

: Average power of the Useful Term

: Average power of the Interference Term

: Average power of the Noise Term

S

I

N

P

P

P

( , )

( , )

1

H

S p

H

S p

SINR

SNR

φ

φ

ψ KS ψ

ψ KI I ψ

: Ratio of two definite positive quadratic

forms on for a given

( , )

( , )

1

H

S p

H

S p

SINR

SNR

ψ

ψ

φ KS φ

φ KI I φ

: Ratio of two definite positive quadratic

forms on for a given

0

: Signal to Noise RatioE

SNRN

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Page 43: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Offline Ping-pong Optimization Philosophy

1/2

Transmitter Side Receiver Side(0)φ

(0 )

(0)

( , )

( , )

Maximize 1

H

S p

H

S p

SINR

SNR

φ

φ

ψ KS ψ

ψ KI I ψ (0)ψ

(0 )

(0 )

( , )

( , )

Maximize 1

H

S p

H

S p

SINR

SNR

ψ

ψ

φ KS φ

φ KI I φ(1)φ

(1)

(1)

( , )

( , )

Maximize 1

H

S p

H

S p

SINR

SNR

φ

φ

ψ KS ψ

ψ KI I ψ (1)ψ

(1)

(1)

( , )

( , )

Maximize 1

H

S p

H

S p

SINR

SNR

ψ

ψ

φ KS φ

φ KI I φ(2)

φ 43

Page 44: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Offline Ping-pong Optimization Philosophy

2/2

φ

ψ

(0)φ

(0)ψ

(1)φ

(1)ψ

(2)φ

44SINR

Equal-SINR curves

(Contour plot of SINR)

SINR maximum

Page 45: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

First Optimization Technique

SINR

0

ψ

( , ) ( , )

1S p S p

SINR φ φ

KI ψ KS ψ

Generalized Eigenvalue Problem

Find the eigenvector with the smallest eigenvalue

SINR

0

φ

( , ) ( , )

1S p S p

SINR ψ ψ

KI φ KS φ

45

Page 46: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Second Optimization Technique

( , )

( , )

H

S p

H

S p

SINR

φ

φ

ψ KS ψ

ψ KIN ψ

( , )

H

S p φKIN UΛU

: Unitary Matrix

: Diagonal Positive Matrix

U

Λ

( , )

H H H H

S p φψ KIN ψ ψ UΛU ψ u u

1/2 Hu Λ U ψ

H

HSINR

u Φu

u u

1/2 1/2

( , )

H

S p

φΦ Λ U KS UΛ

maxFind the eigenvector of with maximum eigenvalueu Φ

1/ 2

max

1/ 2

max

opt

UΛ uψ

UΛ u46

Page 47: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Signal and Interference Kernel Computation

1/3

1

( , )

0

( )k

KH

S p nN k p

n k

φ

K Σ Σ φφ Ω

0 ( ( )) if ( )mod 0

0 else

D s

pq

QJ B T p q p q Q

1

0 ( , )

0

( )k

KH

S p k p

k

φ

K Σ φφ Π

0( ( ))pq D sJ B T p q

( , ) 0 ( , )S p S p φ φKS K ( , ) ( , ) 0 ( , )S p S p S p φ φ φ

KI K K

Π Q Ω

Dependence on channel Doppler (Computed once)

DN Q

47

Page 48: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Signal and Interference Kernel Computation

2/3

φ H φφ

1

0

( )k

KH

k p

k

Σ φφ

Duration: DT

DN samples

48

Matrix shifts according to

the multipath power profile

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Signal and Interference Kernel Computation

3/3

Matrix shifts according to

the normalized symbol duration N

49

1

0

( )k

KH

nN k p

n k

Σ Σ φφ

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Numerical Results: Impact of Initialization and

Existence of Local Maxima

50

Local maxima

Conjecture to

be the global

maximum

Page 51: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Evolution of Transmit and

Receive Pulse Shapes Through the Iterations

51

Iterations: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,…,20,…,30,…,100

φ ψ

Initialization: Gaussian pulse

Page 52: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Doppler Spread-Delay Spread

Balancing

52

Best balancing

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Numerical Results: Optimized Waveforms

53

Page 54: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Optimized Waveforms

54

Page 55: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Performance and Gain in

SINR – Identical Pulse Shape Durations

55

Gain > 5dB

Page 56: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Uneven Distribution of PHY

Delay/Complexity Between Transmitter and

Receiver 1/2

56

PHY delay = (D+D)/2 = 3T

Page 57: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Uneven Distribution of PHY

Delay/Complexity Between Transmitter and

Receiver 2/2

57

PHY delay = (D+D)/2 = 5T

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Numerical Results: Spectrum of One Subcarrier

58

~ 60 dB

Page 59: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Spectrum of 64 Subcarriers

59

~ 60 dB

Page 60: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Sensitivity to an Estimation

Error on BdTm

60

Page 61: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Sensitivity to Synchronization

Errors in Frequency

61

Tolerence margin > 10%

Page 62: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Numerical Results: Sensitivity to Synchronization

Errors in Time

62

38-sample error tolerence

34-sample error tolerence

Page 63: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 1/9

63

T

F

2F

( , )

( , )

/ 2

0

n m

n m

t T T n

f F m

T/2

Page 64: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 2/9

1

0 ( , )

0

( )k

KH

S p k p

k

φ

K Σ φφ Π

0( ( ))pq D sJ B T p q

Π

Dependence on channel Doppler for the 0th Kernel

DN

64

Page 65: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 3/9

1 1

( , ) /2

0 0

( ) ( )k k

K KH even H odd

S p nN k p nN N k p

n k n k

φ

K Σ Σ φφ Ω Σ Σ φφ Ω

0 ( ( )) if ( )mod 02 2

0 else

even D s

pq

Q QJ B T p q p q

Dependence on channel Doppler for the infinite kernel65

0

0

( ( )) if ( )mod 02

( ( )) if ( )mod2 2

0 else

D s

odd

pq D s

QJ B T p q p q Q

Q QJ B T p q p q Q

Page 66: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 4/9

2

even Q Ω

Dependence on channel Doppler for the infinite kernel

/ 2Q

66

2

odd Q Ω

/ 2Q

Even carrier contribution mask Odd carrier contribution mask

Page 67: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 5/9

67

1

0

( )k

KH

nN k p

n k

Σ Σ φφ

1

/2

0

( )k

KH

nN N k p

n k

Σ Σ φφ

Selection on which is

based kernel computation

Even carrier contribution

Odd carrier contribution

Page 68: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 6/9

68

Page 69: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 7/9

69

Rectangular lattice

Hexagonal/quincunx

lattice

Page 70: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 8/9

70

Page 71: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Staggered (Hexagonal/Quincunx) Time-

Frequency Lattice 9/9

71

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Transmit and Receive Waveforms with Unequal

Durations 1/7

72

MSBS

Waveforms for the Downlink

MSBS

Waveforms for the Uplink

t t t t

D D D D

φφ ψ ψ

The BS can afford more complexity in terms of filtering than the MS

Page 73: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Transmit and Receive Waveforms with Unequal

Durations 2/7

73

x =D N

D N

ψ Hψ

Hψψ

Assumption: D D

Given , we search for ψ φ

Page 74: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Transmit and Receive Waveforms with Unequal

Durations 3/7

74

D N

D N

Selection on which is

based the kernel for

the computation of φ

Page 75: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Transmit and Receive Waveforms with Unequal

Durations 4/7

75

x =

D N

D N

φ Hφ

Hφφ

Assumption: D D

Given , we search for φ ψ

Page 76: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Transmit and Receive Waveforms with Unequal

Durations 5/7

76

D N

D N

Selection on which is

based the kernel for

the computation of ψ

Page 77: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Transmit and Receive Waveforms with Unequal

Durations 6/7

77

Page 78: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Transmit and Receive Waveforms with Unequal

Durations 7/7

78

Page 79: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

SINR Kernal Characteristics and Consequences

1/4

79

( , ) ( , )

( , ) ( , )

1 1

H H

S p S p

H H

S p S pSNR SNR

ψφ

ψφ

ψ KS ψ φ KS φ

ψ KI I ψ φ KI I φ

Time reverse of φ

Time reverse of ψ

Page 80: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

SINR Kernal Characteristics and Consequences

2/4

80

φ ψφψ

In terms of noise correlation at the receiver

φ ψφψ

In terms of SINR

Not always equivalent

Page 81: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

SINR Kernal Characteristics and Consequences

3/4

81

PC

Timeφ

ψ Time

CP-OFDM

Timeφ

ψ Time

ZP-OFDM

ZP

Only in terms of SINR

Time

reversing

CP-OFDM and ZP-OFDM are duals of each other

Page 82: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

SINR Kernal Characteristics and Consequences

4/4

82

If the optimum couple (, ), maximizing the SINR, is unique, then

ψ φ

Page 83: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Adaptive Waveform Communication: A New

Link Adaptation Paradigm 1/5

83d mB T

SINR [dB]

Best achieved SINR for each BdTm,

using always the optimum pair (, )

1( )d mB T 2( )d mB T

SINR performance for pair (1, 1)

optimized for (BdTm)1

SINR performance for pair (2, 2)

optimized for (BdTm)2

Page 84: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Adaptive Waveform Communication: A New

Link Adaptation Paradigm 2/5

84d mB T

SINR [dB]

Best achieved SINR for each BdTm,

using always the optimum pair (, )

Use of pair (1, 1) Use of pair (2, 2)

Waveform Codebook

Page 85: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Adaptive Waveform Communication: A New

Link Adaptation Paradigm 3/5

85d mB T

SINR [dB] Instantaneous and average losses in SINR

A priori distributions of BdTm

Most seen SINR loss

for the red a priori

Most seen SINR loss

for the blue a priori

Page 86: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Adaptive Waveform Communication: A New

Link Adaptation Paradigm 4/5

86d mB T

SINR [dB]Codebook optimization:

Notion of multiple codebooks

2 different services 2 different a priori distributions of BdTm

Codebook #1

Codebook #2

A priori distribution

for service #1

A priori distribution

for service #2

Page 87: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Adaptive Waveform Communication: A New

Link Adaptation Paradigm 5/5

87With full characterization of the scattering function

dB

mT

A priori distributions

of (Bd, Tm) corresponding

to different services

(Bd, Tm) values for which

pairs of waveforms

constituting the

codebook are optimized

Page 88: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Conclusion and Perspectives for Future Research

Work on 5G

88

Page 89: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Conclusion

We proposed a new and straightforward technique for the

systematic offline optimization of transmit and receive

waveforms for OFDM/FBMC systems

Increased SINR

6 orders of magnitude reduction in out-of-band emissions

using rectangular time-frequency lattice

7 orders of magnitude reduction in out-of-band emissions

using hexagonal time-frequency lattice

Unequal time durations for transmit and receive

waveforms to adapt to affordable computational resources

Robustness to synchronization errors89

Page 90: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Ongoing Research Work

Current extensions to:

OFDM/OQAM

Reverse-time channel

Unequal-duration waveforms

Hexagonal-lattice OFDM/QAM

Partial equalization

Single-carrier (satellite) communications

OFDMA/QAM

Multi-pulse OFDM/QAM

Windowed OFDM

Faster-than-Nyquist (FTN) signalling

Unique-Word OFDM90

Page 91: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

Perspectives

Future extensions to:

Multi-pulse OFDM/OQAM

Hexagonal-lattice OFDM/OQAM

Underwater acoustic communications

Relaxed synchronization (RACH, MTC)

Carrier aggregation and reduced out-of band emissions

Low latency communications

RADAR/SONAR

5G interface optimization (Standardization inside 3GPP RAN-L1)

91

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92

Thank You for Your Attention!

Mohamed Siala

MEDIATRON Laboratory

Higher School of Communication of Tunis (SUP’COM)

Carthage University - Tunisia

Boğaziçi Üniversitesi

Beşiktaş/İstanbul - Türkiye

May 11, 2016

Page 93: Lecture boğaziçi üniversitesi   2016 presentation - offline ping-pong optimized pulse shaping for future 5 g systems - pops-fbmc vf

References 1/4

M. Siala, T. Kurt, and A. Yongaçoglu, “Orthonormalization for Multi-Carrier Transmission,”

Canadian Workshop on Information Theory 2005 (CWIT’05), Montreal, Quebec, Canada, June 2005.

T. Kurt, M. Siala, and A. Yongaçoglu, “Multi-Carrier Signal Shaping Employing Hermite

Functions,” European Signal Processing Conference 2005 (EUSIPCO’05), Antalya, Turkey,

September 2005.

N. Debbabi, M. Siala, and H. Boujemâa, “Optimization of the OFDM Prototype Waveform for

Highly Time and Frequency Dispersive Channels Through a Maximization of the SIR,” 12th

IEEE International Conference on Electronics, Circuits and Systems 2005 (ICECS’05), Gammarth,

Tunisia, December 2005.

A. Ben Salem, M. Siala, and H. Boujemâa, “Performance Comparison of OFDM and

OFDM/OQAM Systems Operating in Highly Time and Frequency Dispersive Radio-Mobile

Channels,” 12th IEEE International Conference on Electronics, Circuits and Systems 2005

(ICECS’05), Gammarth, Tunisia, December 2005.

M. Siala, T. Kurt, and A. Yongaçoglu, “A Unified Framework for the Construction of

OFDM/OQAM Systems,” 12th IEEE International Conference on Electronics, Circuits and Systems

2005 (ICECS’05), Gammarth, Tunisia, December 2005.

93

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References 2/4

A. Ben Salem, M. Siala, and H. Boujemâa, “OFDM systems with hexagonal time-frequency

lattices and well time frequency localized prototype functions,” Third International Symposium

on Image/Video Communications over fixed and mobile networks 2006 (ISIVC’06), Hammamet,

Tunisia, September 2006.

M. Siala, “Novel OFDM/OQAM system with hexagonal time-frequency lattice,” Third

International Symposium on Image/Video Communications over fixed and mobile networks

(ISIVC’06), Hammamet, Tunisia, September 2006.

I. Trigui, M. Siala, and H. Boujemâa, “Optimized pulse shaping for OFDM multi-user

communications over doubly dispersive channels,” 9th International Symposium on Signal

Processing and its Applications (ISSPA’07), Sharjah, United Arab Emirates, February 2007.

M. Siala and A. Yongaçoglu, “Prototype waveform optimization for an OFDM/OQAM system

with hexagonal time-frequency lattice structure,” 9th International Symposium on Signal

Processing and its Applications (ISSPA’07), Sharjah, United Arab Emirates, February 2007.

I. Trigui, M. Siala, S. Affes and A. Stephenne, “SIR Optimized Hermite-Based Pulses for BFDM

Systems in Doubly Dispersive Channels,” International Symposium on Signals, Systems and

Electronics (ISSSE’07), Montreal, Quebec, Canada, July 2007.

94

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References 3/4

R. Ayadi, I. Kammoun, and M. Siala, “Optimization of the pulse shape of OFDM systems Using

the Arrow-Hurwicz Algorithm,” 4th International Symposium on Wireless Communication Systems

(ISWCS’07), Trondheim, Norway, October 2007.

R. Ayadi, M. Siala, and I. Kammoun, “Transmit/receive pulse-shaping design in BFDM systems

over time-frequency dispersive AWGN channel,” IEEE International Conference on Signal

Processing and Communications (ICSPC’07), Dubai, United Arab Emirates, November 2007.

I. Trigui, M. Siala, S. Affes, A. Stephenne, and H. Boujemaa, “Optimum Pulse Shaping for

OFDM/BFDM Systems Operating in Time Varying Multi-Path Channels,” IEEE Global

Telecommunications Conference (GLOBECOM’07), Washington DC, USA, November 2007.

M. Bellili, M. Siala, and L. Ben Hadj Slama, “Pulse design for maximizing SIR in partially

equalized OFDM/BFDM systems,” IEEE 19th International Symposium on Personal, Indoor and

Mobile Radio Communications (PIMRC’08), Cannes, France, September 2008.

M. Bellili, L. Ben Hadj Slama, and M. Siala, “Multi-pulse/single-pulse design for maximizing SIR

in partially equalized OFDM systems over highly dispersive channels,” 16th IEEE International

Conference on Electronics, Circuits, and Systems, 2009 (ICECS 2009), Hammamet, Tunisia,

December 2009.

95

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References 4/4

R. Ayadi, I. Kammoun, and M. Siala, “Optimal OFDM Pulse Design, Analysis and

Implementation Over Doubly Dispersive Channel,” 21st European Signal Processing Conference

(EUSIPCO 2013), Marrakech, Morocco, September 9-13, 2013.

M. Siala, F. Abdelkefi and Z. Hraiech, “Novel Algorithms for Optimal Waveforms Design in

Multicarrier Systems,” IEEE Wireless Communications and Networking Conference

(WCNC’2014), Istanbul, Turkey, April 2014.

Z. Hraiech, M. Siala, and F. Abdelkefi, “Numerical Characterization for Optimal Designed

Waveform to Multicarrier Systems in 5G,” 22nd European Signal Processing Conference 2014

(EUSIPCO’2014), Lisbon, Portugal, 1-5 September 2014.

Z. Hraiech, F. Abdelkefi, and M. Siala, “POPS-OFDM: Ping-pong Optimized Pulse Shaping-

OFDM for 5G systems,” IEEE International Conference on Communications (ICC’15), London,

UK, June 2015.

Z. Hraiech, F. Abdelkefi, and M. Siala, “POPS-OFDM: Ping-pong Optimized Pulse Shaping-

OFDM for 5G systems,” IEEE Vehicular Technology Conference – Spring 2015 (VTC’S15),

Glasgow, Scotland, May 2015.

Z. Hraiech, F. Abdelkefi, and M. Siala, “POPS-OFDM with different Tx/Rx pulse shape

durations for 5G systems,” Fifth International Conference on Communications and Networking

(COMNET’2015), Hammamet, Tunisia, November 2015. 96