多径衰落信道中M进制直接序列扩频系统RAKE接收机性能分析

Performance of M-ary Direct-Sequence Spread Spectrum RAKE Receiver in Multipath Fading Channel

本文分析了存在码片定时误差和载波相位估计误差情况下 ,采用BPSK调制的M进制正交码直接序列扩频信号在多径衰落信道下的RAKE接收机性能 .分别讨论了不使用分集和采用选择式合并、等增益合并和最大比合并三种分集合并策略时接收信号的误码率 ,并推导出相应的近似计算方法 .文章最后在此基础上分析了不同的分集合并办法。

The error probability expressions for BPSK modulated M ary direct spread spectrum systems with coherent RAKE receivers are derived in Rayleigh fading channel,which take into account the effect of chip timing and carrier phase errors.Non diversity and three types of diversity schemes are considered:selection diversity,equal gain diversity combining,and maximal ratio diversity combining.Also,the approximate expressions of the error probability are derived.Finally,channel characteristics,diversity schemes,and synchronization errors’effects on the performance are discussed.