EM-based Multi-User Detection for STBC-MC-CDMA communication systems

In this paper, a sub-optimum multi-user detection (MUD) algorithm is investigated in the synchronous case of the downlink for a space-time block coded multi-carrier code division multiple access (MC-CDMA) communication system over dispersive wireless channel based on the expectation maximization (EM) algorithm. In particular, the expectation and maximization steps of the EM algorithm are derived, and the performance of the non-linear iterative algorithm is compared with different iterative Parallel and Successive Interference Cancellers (IC) such as MMSE-PIC and MMSE-SIC detectors as well as ZF-PIC and ZF-SIC detectors. It is seen that the proposed detection algorithm is efficient from complexity points of view. The numerical results also demonstrate the efficiency of the algorithm in the scenes of bit error rate performance.