Hybrid local search polynomial-expanded linear multiuser detector for DS/CDMA systems

This work proposes a new multiuser detector for DS/CDMA systems constituted by the polynomial Minimum Mean-Squared Error (MMSE) detector followed by a local search algorithm 1-adapt LS (one-adaptive local search), namely the hybrid 1-adapt-LS-MuD. In order to reduce computational complexity inherent to recurrent computation of the cross-correlation matrix inverse in DS/CDMA multiuser detection (MuD), this work introduces for the first time a hybrid multiuser detector based on polynomial expansion (PE-MuD) with α-estimation aided by Gerschgorin circles (GC), followed by a low-complexity local search procedure, aiming at obtaining a near-optimum multiuser Bit-Error-Rate (BER) performance, but with a considerable saving in computational complexity. The proposed hybrid PE-MuD receiver topology is analysed under realistic wireless mobile channels, as well as useful system operation scenarios. Numerical results obtained via Monte Carlo Simulations (MCS) have indicated a remarkable improvement in performance-complexity trade-off regarding the classical Linear Multiuser Detectors (LMuD) performance, particularly, the Mean Square Error Minimisation- Based Detector (MMSE-MuD). Copyright © 2013 Inderscience Enterprises Ltd.