SAGE Based Data Detection for Multiuser Spatial Modulation with Large Number of Receive Antennas

In this letter, we propose to exploit the concept of space-alternating generalized expectation maximization (SAGE) to resolve the data detection for multiuser spatial modulation (SM) systems with a large number of receive antennas. The proposed SAGE based detector recursively perform data detection for each user with multiuser interference (MUI) cancellation from the other users. The standard SAGE detector may converge to a local extremum point which results in observable performance degradation under the high signal-to-noise (SNR) region. To further improve the performance, we propose a new list recursive SAGE based detector, where at each cycle during the iteration procedure, the redundant MUI terms are removed and a very small list of detection candidates are reserved for each user. The simulation results are provided which show that the proposed list recursive detector can closely approach the single-user performance benchmark, and can substantially outperform the existing competitor especially with QAM constellations.