Comparative Analysis of Multiuser Detection Techniques in SDMA-OFDM System over the Correlated MIMO Channel Model for IEEE 802.16n

Space-Division Multiple Access-OFDM based wireless communication has the potential to significantly increase the spectral efficiency, system performance and number of users. Research in the development of efficient Multiuser Detection (MUD) algorithms for such systems has generated much interest in recent years. The linear Minimum Mean Square Error (MMSE) MUD processes with low complexity but it is limited by its poor performance. The maximum likelihood (ML) detection provides the optimal performance, but its complexity increases exponentially with the number of users. The Successive Interference Cancellation (SIC) and QR decomposition (QRD) MUD can be a substitute to ML detection due its low complexity and near optimal performance. However, all these techniques are incapable to detect users in rank deficient scenario, where number of users is more than that of number of receiving antennas. Hence, the Minimum Bit Error Rate (MBER) MUD by minimizing probability of error directly has become a possible alternative to all aforementioned MUDs in rank deficient scenario and also its BER performance is close to ML detector. This research proposes a comparative analysis of all these MUD schemes. In this paper the performance of various MUD techniques is verified for the correlated MIMO channel models based on IEEE 802.16n standard.