International Journal of Engineering and Technology

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 non-Gaussian 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 M-estimator 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.