Hybrid Local Search Polynomial-Expanded Linear Multiuser Detectors for SIMO DS/CDMA Systems

In order to reduce computational complexity inherent to recurrent cross-correlation matrix inversion in a single-input-multiple-output (SIMO) direct-sequence code division multiple access (DS/CDMA) system, this work proposes a hybrid multiuser detector based on polynomial expansion (PE-MuD) followed by a low complexity local search procedure, aiming at obtaining a near-optimum multiuser bit-error-rate (BER) performance, but with an amount of computational processing saving time. The proposed hybrid PE-LS-MuD receiver topology suitable for multiple antennas DS/CDMA systems is analyzed under realistic wireless mobile channels, as well as useful system operation scenarios. Simulations results have indicated an improvement in performance-complexity trade-off regarding the classical linear multiuser detectors (LMuDs) performance, particularly, the mean square error minimization-based detector (MMSE).