PSO Based Multiuser Detection over GK Fading Channels with MRC Receive Diversity in Impulsive Noise

Abstract— The direct sequence-code division multiple accesses (DS-CDMA) signals are transmitted over multipath channels that introduce fading and shadowing. Combined effect of multipath fading and shadowing along with multiple access interference (MAI) and inter-symbol interference (ISI) worsens the system performance. Further, experimental results have confirmed the presence of impulsive nonGaussian noise in wireless mobile communication channels. Hence, this paper presents a particle swarm optimization (PSO) based multiuser detection technique for DS-CDMA systems over generalized-K (GK) fading channels in presence of impulsive noise. Maximal ratio combining (MRC) receive diversity is also incorporated to mitigate the effects of fading and shadowing. An approximate closed-form expression for average error rate of BPSK signals over GK fading channels is derived. Performance of proposed Mestimator based detector is also studied by evaluating average error rate. Simulation results reveal that the proposed M-estimator based detector performs better in the presence of fading, shadowing and heavy-tailed impulsive noise when compared to least squares, Huber and Hampel M-estimator based detectors. Keyword-diversity combining, fading channel, GK distribution, impulsive noise, multiuser detection, probability of error, particle swarm optimization, shadowing