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

Authors: Reinaldo Götz; Taufik Abrão

Addresses: Electrical Engineering Department, State University of Londrina, Rod. Celso Garcia Cid - PR445, Campus Universitário, P.O. Box 6001, 86051-970, Londrina, PR, Brazil ' Electrical Engineering Department, State University of Londrina, Rod. Celso Garcia Cid - PR445, Campus Universitário, P.O. Box 6001, 86051-970, Londrina, PR, Brazil

Abstract: 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).

Keywords: near-optimum search algorithms; polynomial-expanded multiuser detection; Gerschgorin circles; DS-CDMA; complexity reduction; local search; Monte Carlo simulation; code division multiple access.

DOI: 10.1504/IJWMC.2013.053043

International Journal of Wireless and Mobile Computing, 2013 Vol.6 No.1, pp.18 - 26

Received: 03 Oct 2012
Accepted: 05 Oct 2012

Published online: 03 Apr 2013 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article