DS-CDMA Detection for Frequency-Selective Multipath Channels by LMS Algorithm
Mangala R. Gajbhiye, J. K. Sathpathy · 2013
The Performance comparison of Minimum Mean Square Errorbased Adaptive Multi-User Detection (MUD) of Direct Sequence-Code Division Multiple Access (DS-CDMA) signals is considered. DS-CDMA is a popular multiple-access technology for wireless communication. But its performance is limited by multiple-access interference (MAI) and multipath distortion. Adaptive techniques, such as least mean squares (LMS) algorithm is employed for detection of DS-CDMA signals which improves the performance of the CDMA system by reducing interference among users. In this paper the diversity scheme called maximum ratio combining (MRC) as preprocessor to the adaptive MMSE detector of DS-CDMA system in frequency-selective multipath channel is introduced and compare the complexities of adaptive techniques. The performance of the proposed detector for frequency-selective multipath channel is simulated. Simulations in frequencyselective multipath channels have proved its better performance compared with the conventional Match Filter detector, and it is performing nearly as well as single user case. KeywordsDirect-sequence code-division multiple access (DS-CDMA), Multipath channel, Minimum mean square error (MMSE), LMS (Least Mean Square) algorithms.