Impact of Residual MAI in MMSE Multiuser Detector

Abstract

The capacity of the CDMA system is restricted by interference. Multiuser detection is one approach for increasing the capacity of a CDMA system. An enhanced MMSE-based multiuser detector is suggested in this study. The traditional detector is designed to resist Additive White Guassian Noise (AWGN), but the MMSE detector has the lowest Bit Error Rate (BER) of any suboptimal linear detector. The proposed detector uses the conventional detector output to make its decision, so a significant improvement is possible. Our simulation results for a synchronous CDMA system show a significant improvement in BER over the MMSE detector.