Power Allocation Strategy for Soft-Decision-and-Forward Cooperative Communication System

연판정 후 전달 방식에 대한 전력 분배 전략

  • 송경영 (서울대학교 전기.컴퓨터 공학부 및 뉴미디어통신공동연구소) ;
  • 김재홍 (서울대학교 전기.컴퓨터 공학부 및 뉴미디어통신공동연구소) ;
  • 노종선 (서울대학교 전기.컴퓨터 공학부 및 뉴미디어통신공동연구소) ;
  • 정하봉 (홍익대학교 전자전기공학부)
  • Published : 2010.01.31

Abstract

In this paper, the performance of the soft-decision-and-forward (SDF) protocol in the cooperative communication network with one source, one relay, and one destination, where each node has two transmit and receive antennas, is analyzed in terms of the bit error rate (BER) obtained from the pairwise error probability (PEP). For the slow-varying Rayleigh fading channel, the optimal and suboptimal power allocation ratios are determined without feedback. The optimal power allocation can be obtained by minimizing the average PEP. For the tractability, an alternative strategy of maximizing the product SNR of direct and relay links, which we call the suboptimal power allocation, is considered. Through the numerical analysis, we show that the performance gap between the suboptimal and the optimal power allocation is negligible in the high SNR region.

본 논문은 하나의 소스, 하나의 릴레이, 그리고 하나의 목적 노드가 각각 두 개의 송수신 안테나를 갖는 협력 통신망에서, 연판정 후 전달(soft-decision-and-forward: SDF) 방식의 성능을 쌍 오류 확률(pairwise error probability: PEP)을 이용해 분석한다. 준정지 레일리 페이딩 채널에서 최적 그리고 차선의 전력 분배비를 결정한다. 최적의 전력 분배는 평균 PEP를 최소로 하는 것이나 일반적으로 구하기 어려우므로, 다이렉트와 릴레이 링크의 잡음 대 신호비의 곱(product signal-to-noise ratio: product SNR)을 최대화하는 전력 분배 전략을 고려한다. 모의실험 결과를 통해 높은 SNR 구간에서는 차선의 전력 분배 방식의 성능이 최적의 성능에 근접함을 보인다.

Keywords

References

  1. A. Sendonaris, E.Erkip, B.Aazhang, "User Cooperation diversity-partⅠ: System description," IEEE Transactions on Communications, 51(11), pp.1927-1938, November 2003. https://doi.org/10.1109/TCOMM.2003.818096
  2. A. Sendonaris, E.Erkip, B.Aazhang, "User Cooperation diversity-partⅡ: Implementation aspects and performance analysis," IEEE Transactions on Communications, 51(11), pp.1939-1948, November 2003. https://doi.org/10.1109/TCOMM.2003.819238
  3. J. N. Laneman, G. W. Wornell, "Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks," IEEE Transactions on Information Theory, 49(10), pp.2415-2425, October 2003. https://doi.org/10.1109/TIT.2003.817829
  4. V. Tarokh, N. Seshadri, A. R. Calderbank, "Space-time codes for high data rate wireless communication: Performance analysis and code construction," IEEE Transactions on Information Theory, 44(3), pp.744-765, March 1998. https://doi.org/10.1109/18.661517
  5. Y. Jing, B. Hassibi, "Distributed space-time coding in wireless relay networks," IEEE Transactions on Wireless Communications, 5(12), pp.3524-3536, December 2006.
  6. X. Li, T. Luo, G. Yue, C. Yin, "A squaring method to simplify the decoding of orthogonal space-time block codes," IEEE Transactions on Communications, 49(10), pp.1700-1703, October 2001. https://doi.org/10.1109/26.957388
  7. I.-H. Lee, D. Kim, "Decouple-and-forward relaying for dual-hop Alamouti transmissions," IEEE Communications Letters, 12(2), pp.97-99, February 2008. https://doi.org/10.1109/LCOMM.2008.071573
  8. S. M. Alamouti, "A simple transmit diversity technique for wireless communications," IEEE Journal on Selected Areas in Communications, 16(8), pp.1451-1458, October 1998. https://doi.org/10.1109/49.730453
  9. J.-D. Yang, K.-Y. Song, J.-S. No, D.-J. Shin, "Soft-decision-and-forward protocol for cooperative communication networks based on Alamouti code," in Proceedings of IEEE ISIT, 2009, pp.1016-1019.
  10. M. O. Hasna, M.-S. Alouini, "Optimal power allocation for relayed transmissions over Rayleigh-fading channels," IEEE Transactions on Wireless Communications, 3(6), pp.1999-2004 November 2004. https://doi.org/10.1109/TWC.2004.833447
  11. X. Deng, M. Haimovich, "Power allocation for cooperative relaying in wireless networks," IEEE Communications Letters, 9(11), pp.994-996, November 2005. https://doi.org/10.1109/LCOMM.2005.11012
  12. M. Chiani, D. Dardari, M. K. Simon, "New exponential bounds and approximations for the computation of error probability in fading channels," IEEE Transactions on Wireless Communications, 2(4), pp.840-845 July 2003.
  13. Y. Han, S. H. Ting, C. K. HO, W. H. Chin, "Performance bounds for two-way amplify-and-forward relaying," IEEE Transactions on Wireless Communications, 8(1), pp.432-439 January 2009. https://doi.org/10.1109/T-WC.2009.080316
  14. F. W. Kneubuhler, "Fading relay channels: Performance limits and space-time signal design," IEEE Journal on Selected Areas in Communications, 22(6), pp.1099-1109, August 2004. https://doi.org/10.1109/JSAC.2004.830922