Performance of optimum and suboptimum multiuser detection in DS-CDMA mobile radio systems in multipath channels

We consider K-user transmission over multipath channels in the synchronous downlink and the asynchronous uplink of a DS-CDMA system. We investigate the multiuser maximum likelihood sequence detector and different types of linear and nonlinear suboptimum multiuser detectors. Complexity considerations are made and simulation results demonstrate the performance of all detectors investigated. Our results show that with multiuser detection schemes even in a multipath environment the capacity of DS-CDMA systems can be increased as compared to conventional detection methods.