Low-Complexity Detector for Spatial Modulation Multiple Access Channels With a Large Number of Receive Antennas

In this letter, a low-complexity detector, called ordered nearest neighbor search (NNS) minimum mean square error (MMSE) detector, is proposed for the spatial modulation multiple-access channel with a large number of receive antennas. In the proposed detector, the antenna index is first determined based on the channel direction information, and then, the modulation signal is recovered by the MMSE detector. Furthermore, to improve the separable detection performance, an ordered candidate list of the antenna index is acquired through NNS. Simulation results show that the proposed detector approaches the interference-free performance with very low complexity.