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LLR-based Cooperative ARQ Protocol in Rayleigh Fading Channel  

Choi, Dae-Kyu (Dept. of Electrical Engineering, University of Ulsan)
Kong, Hyung-Yun (Dept. of Electrical Engineering, University of Ulsan)
Publication Information
Journal of the Institute of Electronics Engineers of Korea TC / v.45, no.4, 2008 , pp. 31-37 More about this Journal
Abstract
Conventional cooperative communications can attain gain of spatial diversity and path loss reduction because destination node independently received same signal from source node and relay node located between source node and destination node. However, these techniques bring about decreased spectral efficiency with relay node and increased complexity of receiver by using maximal ratio combining (MRC). This paper has proposed cooperative ARQ protocol that can improve the above problems and can get the better performance. This method can increase the spectral efficiency than conventional cooperative communication because if the received signal from source node is satisfied by the destination preferentially, the destination transmits ACK message to both relay node and source node and then recovers the received signal. In addition, if ARQ message indicates NACK relay node operates selective retransmission and we can increase reliability of system compared with that of general ARQ protocol in which source node retransmits data. In the proposed protocol, the selective retransmission and ARQ message are to be determined by comparing log-likelihood ratio (LLR) computation of received signal from source node with predetermined threshold values. Therefore, this protocol don't waste redundant bandwidth with CRC code and can reduce complexity of receiver without MRC. We verified spectral efficiency and BER performance for the proposed protocol through Monte-Carlo simulation over Rayleigh fading plus AWGN.
Keywords
Cooperative communication; ARQ; MRC; Rayleigh fading; LLR;
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1 S. W. Kim and E. Y. Kim, "Optimim receive antenna selection minimizing error probability," WCNC2003, Vol. 1, pp. 441-447, March 2003
2 H. Hu, Yanikomeroglu H, Falconer D. D., and S. Periyalwar, "Range extension without capacity penalty in cellular networks with digital fixed relays," Global Telecommunications Conference, GLOBECOM '04, Vol. 5, pp. 3053-3057. Nov. 2004
3 N. Ahmed, M. A. Khojastepour, and B. Aazhang, "Outage minimization and optimal power control for the fading relay channel," IEEE Information Theory Workshop, pp. 458-462, Oct. 2004
4 Laneman, J. N., Tse, D. N. C., Wornell, and G. W, "Cooperative diversity in wireless networks: Efficient protocols and outage behavior," Information Theory, IEEE Transactions on, Vol. 50, Issue 12, pp. 3062-3080. Dec. 2004
5 A. Sendonaris, E. Erkip, and B. Aazhang, "User cooperation diversity Part I-II," IEEE Trans. on Communications, Vol. 51, No. 11, pp. 1927-1948, Nov. 2003   DOI   ScienceOn
6 V. Tarokh, H. Jafarkhani, and A. R. Calderbank, "Space-time block coding for wireless communications: performance results," IEEE Trans. On Commun., Vol. 17, Issue 3, pp. 451-460, March 1999
7 Ho Van Khuong and Hyung-Yun Kong, "LLR-based Decode-and-Forward Protocol for Relay Networks and Closed-form BER Expressions," IEICE, Vol. E89-A No. 6 pp. 1832-1841. Jun. 2006   DOI   ScienceOn
8 A. Nosratinia, T. E. Hunter, and A. Hedayat, "Cooperative Communication in Wireless Networks," IEEE Communications Magazine, Vol. 42, Issue 10, pp. 74-80, Oct. 2004   DOI   ScienceOn
9 E. Malkamaki and H. Leib, "Performance of truncated type-II hybrid ARQ schemes with noisy feedback over block fading channels," IEEE Trans. Commun., Vol. 48, pp. 1477-1487, Sept. 2000   DOI   ScienceOn