Low-Complexity Detections for Downlink MIMO MC-CDMA Systems

In this paper, we investigate and propose the detection techniques for spatially layered multiple-input multiple-output (MIMO) multi-carrier code division multiple access (MC-CDMA) systems. First, we propose a noise-predictive linear detector. It has the same bit error rate (BER) performance as symbol-level detector and reduces the complexity significantly when the system load is almost full. We also propose a partial minimum mean square error (MMSE)-ordered successive interference cancellation (OSIC) based on multi-user detection, which first detects the most powerful interfering data symbols transmitted through the determined transmit antenna and then cancels their contribution from the received signal by the multiplexed data symbol vector. The nulling and cancelling processes between the user data symbols from the same transmit antenna are not performed. The proposed algorithms are verified by computer simulation