Turbo multiuser detection for STBC MC-CDMA uplink systems using hybrid particle swarm optimization algorithm

We propose in this paper a near-optimal and reduced-complexity turbo multiuser receiver for space-time block-coded (STBC) multi-carrier code division multiple access (MC-CDMA) uplink systems over frequency selective multi-input multi-output (MIMO) fading channels. Since optimal soft-in soft-out (SISO) multiuser detector based on a posteriori probability (APP) algorithm has an exponential computational complexity, a novel SISO multiuser detector employing hybrid particle swarm optimization (PSO) algorithm is developed. The proposed hybrid algorithm which takes the virtue of PSO and the Hopfield neural network (HNN) has better global search ability and faster convergence comparing with other heuristic algorithms. The proposed receiver can achieve bit-error-rate (BER) performance close to that of optimal APP algorithm with significantly lower complexity.