Performance comparison of MMSE-based adaptive multiuser detection of DS-CDMA signals

Direct-sequence code-division multiple access (DS-CDMA) is a popular multiple-access technology for wireless communication. However its performance is limited by multiple-access interference (MAI) and multipath distortion. Adaptive techniques for detection of DS-CDMA signals improves the performance of the CDMA system by reducing interference among users by employing two major types of adaptive technique called least mean squares (LMS) and recursive least square (RLS) in non-dispersive channels. In this paper the diversity scheme called maximum ratio combining (MRC) as preprocessor to the adaptive MMSE detector of DS-CDMA system in multipath channel is introduced and compare the complexities of adaptive techniques.