On channel coding for CDMA over multipath Rayleigh fading channels

This work considers asynchronous DS-CDMA systems with single-user receivers. The focus, is on combined error control/PN sequence spreading. This work shows that the best performance is achieved when all the bandwidth expansion is by error control coding, instead of by PN sequences. This conclusion is valid for all types of fading channels. Comparisons of CDMA systems using different error control schemes are presented, keeping constant the total available bandwidth and the information rate. Both DBPSK and /spl pi//4 DQPSK modulation with noncoherent demodulation are analysed.