DS/CDMA with predetection diversity over a frequency selective multipath Rayleigh-fading channel

This paper investigates the bit error rate performance of a direct sequence code division multiple access (DS/CDMA) system with predetection diversity over a frequency selective multipath Rayleigh-fading channel. Differential phase-shift-keying (DPSK) modulation and noncoherent demodulation are considered. It is shown that predetection diversify is relatively more efficient in improving the BER performance of the system when the channel conditions are worse. If is also shown that a large number of resolvable paths are beneficial when they are all combined to combat the multipath fading