全双工协作通信系统中分布式Alamouti空时编码的性能分析

摘要

针对存在残留自干扰(RSI)的3节点全双工协作通信系统,研究分布式Alamouti空时码(DASTC)的差错性能.通过分析成对差错概率及其在高发射功率下的渐进表达式,导出了系统的分集增益和编码增益;进一步分析残留自干扰对分布式空时码编码结构的影响,导出了分集增益的可达条件.理论分析和仿真结果表明,在高发射功率和小残留干扰下,DASTC在全双工协作通信系统中是一种全速率、满分集的空时码,在相同频谱效率下的差错性能优于半双工协作通信系统;充分抑制自干扰能获得更高的分集增益和编码增益,并强化分集增益的可达性,提高系统的频谱效率和能量效率.%The error performance of distributed Alamouti space-time code (DASTC) was investigated in a 3-node full-duplex (FD) cooperative communication system with the presence of residual self-interference (RSI).Based on the asymptotic expression of the pairwise error probability in the high transmit power region,the diversity and coding gain were derived.The impact of residual self-interference on the construction of space-time code was analyzed and the achievable condition of diversity gain was obtained.Analytical results show that DASTC achieves full rate and full diversity in the FD cooperative communication system with high transmit power and low RSI.The error performance of the FD system is superior to which of the half-duplex system under the same spectral efficiency constraint.The diversity and coding gain can be increased by sufficiently suppressing the self-interference,and the spectral efficiency and power efficiency can be improved as well.