Performance of low complexity multiuser detection in MIMO-OFDM systems

Multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) techniques are combined to attain high capacity or good performance over frequency selective channels. This paper considers an in-depth analysis of various MIMO detectors and their performance in terms of Mean Square Error (MSE) and Bit Error Rate (BER). Also a low complexity solution is applied and the complexity is reduced by 50 %. Two MIMO detectors can be combined to improve the performance. Here Zero Forcing (ZF) and Successive Interference Cancelletion (SIC) are combined and found that the performance is better than ZF. The proposed technique has features of both ZF and SIC detections. BER results for ZF is compared with ZF-SIC detection to demonstrate the viability of the chosen solutions and their benefits over the existing MIMO detections. From simulation results, around 2.2dB of improvement for BER of 10-3 is obtained by using this combined ZF and SIC method. The simulations are executed in Rayleigh multipath fading channels.