Post on 24-Jun-2015
Channel gain survey
報告者 : 李杰修指導教授 : 劉宏煥
References Ki-Dong Lee and Victor C. M. Leung, “capacity planning for group-mobile user in OFDMA
wireless networks,” EURASIP Journal. Wireless Communications and Networking, vol. 2006, pp. 1-12.
Zhu ji, K.j. Ray Liu, “Fair Multiuser channel allocation for OFDMA Networks Using Nash Bargaining Solutions and Coalitions,” IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 53 NO. 8, AUGUST 2005.
Seong Taek Chung, Andrea J. Goldsmith, “Degrees of Freedom in Adaptive Modulation : A Unified View,” IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 49 NO. 9,
SEPTEMBER 2001.
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Outline
• Introduction• System model
– Cost function– Parameter matrix– Bit-error rate(BER) – Transmission rate
• Simulation result• Conclusion && future work 112/04/13 3
Introduction
Planned admission capacity should be adjust with channel gain
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Introduction(cont)
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Depend on channel gain choose multi-subcarrier for multi-user
Cost function
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K : user numberN : subcarrier number
Cost function(cont)• i user transmission rate
• Subcarrier-assignment matrix [A]ij = a ij (i user, j subcarrier)
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i : user j : subcarrierN: subcarrier number
Bit-error rate(BER) of MQAM
ith user SNR at jth subcarrier P : power G : channel gain σ : noise power
Bit-error rate(BER) of MQAM C1 = 0.2 C2 = 1.5
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2
ij
ij
Transmission rate
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ij
W :Subcarrier bandwidth
Simulation result
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Simulation result(cont)
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Simulation result(cont)
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Average rate per connection
• Achievable rate of user j using subcarrier i
• Average rate per connection when y connections are ongoing as follows
)σ
PGa(WC ijij
ij 22 1log
)σ
)P(y/cGa(W
y
CR(y)
22 1log
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Conclusions
• We need “transmission rate” to planned admission control scheme
• “Channel gain” is the necessary parameter for compute transmission rate
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Future work
• Channel gain – flat Rayleigh fading model– Jakes model
• Autocorrelation channel gain
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