频率选择性衰落信道下DS-CDMA系统发射分集技术

Transmit Diversity Technique for DS-CDMA Systems in a Frequency Selective Fading Environment

本文研究多径频率选择性衰落信道下 ,DS CDMA系统开环发射分集技术 .提出了一种将线性多用户检测与发射分集相结合的新方法 ,该方法能在克服信道衰落的同时抑制多址干扰和码间串扰 .针对两种不同的扩频码分配方式 ,本文分别给出了盲和半盲的信道估计和检测算法 .仿真结果表明 ,本文所提方法的性能优于基于空时分组码的RAKE接收机 。

In this paper,the method of using open loop transmit diversity in a multi user DS CDMA system operating in a frequency selective fading environment is considered.A novel approach is proposed for linear multi user detection in conjunction with transmit diversity to combat channel fading,multi user interference and inter symbol interference.By assigning spreading codes,blind and semi blind algorithms are developed for channel estimation and detection.Simulation results demonstrate that the proposed technique offers substantial performance over the RAKE receiver based on space time block codes,especially in a near far situation.