Performance Comparison of Linear Multiuser Detectors for DS/CDMA Systems in AWGN

Abstract

Direct sequence code division multiple access (DS-CDMA) is a popular wireless technology. This system suffers from Multiple Access Interference (MAI) caused by Direct Sequence users and Near–Far effect due to different power levels received. Multi-User Detection schemes are used to detect the users' data in the presence of MAI and Near–Far problem. In this paper, presented comparative study between linear multiuser detectors and conventional single user matched filter in DS-CDMA system. Analysis and simulations are conducted in synchronous AWGN channel, and Gold sequence is used as the spreading code. Simulation results describe the performance of Conventional detector, Decorrelating detector and MMSE (Minimum Mean Square Error) detector. It shows that the performance of these detectors depends on the length of PN code used and Number of users. Linear multiuser detectors perform better than the conventional matched filter in terms of BER performance.