时变瑞利信道下反馈时延对选择发送分集性能的影响  

The Impact of Feedback Delay to the Performance of Selective Transmit Diversity under Time-Varying Rayleigh Channel

作　　者：赵爽[1] 杨鸿文[1] 

机构地区：[1]北京邮电大学信息与通信工程学院,北京100876

出　　处：《北京邮电大学学报》2009年第4期94-98,共5页Journal of Beijing University of Posts and Telecommunications

基　　金：国家高技术研究发展计划项目(2007AA01Z211);国家自然科学基金项目(60602060)

摘　　要：研究了在时变瑞利衰落信道下,存在反馈时延的选择发送分集(STD)系统的性能.推导了存在反馈时延时,STD系统的输出信噪比分布和BPSK调制的误比特率(BER)表达式.分析并证明了在此种情况下,STD系统的BER实际由2部分组成:一部分是无反馈时延的理想STD系统的BER;另一部分是分集度为1的BER"平台".指出只要反馈时延存在(无论多小),任何STD系统的理论分集度都为1.The performance of selective transmit diversity （STD） with feedback delay is investigated under time-varying Rayleigh channel. First, the closed-form expressions of the receiver output signal to-noise ratio （SNR） distribution are derived and validated via simulation. Based on these results, the bit error rate （BER） of BPSK modulation is obtained. It is shown that the BER of STD system con- sists of two parts： the BER of an ideal STD system without feedback delay plus an error floor of diversity order one representing the contribution of delayed feedback. No matter how small the feedback is, the error floor always exists. In consequence, the theoretical diversity order is one for any STD system with none zero feedback delay.

关 键 词：选择发送分集 反馈时延 误比特率“平台” 分集度 

分 类 号：TN914[电子电信—通信与信息系统]