Error Performance of DS-CDMA over Multipath Channel Using Selective Rake Receiver

Error performance of DS-CDMA is discussed over independent Rayleigh faded multipath channel employing selective Rake (SRake) receiver. Simple-to-evaluate and accurate error probabilities are given following Holtzman’s simplified improved Gaussian approximation (SIGA). Comparing with SIGA, the validity of standard Gaussian approximation (SGA) is then verified. It is shown that SGA is accurate for SRake until some number of combined paths beyond which it becomes optimistic. It is also shown that as compared to single user performance, the SRake performance is relatively less degraded by multiple access interference (MAI) while the number of combined paths is small. key words: DS-CDMA, multipath channel, selective Rake receiver, standard and improved Gaussian approximations