Preprocessing Aided Spatial Modulation for Multi-User MIMO Downlink Transmission with Imperfect CSIT

摘要

In this paper, the preprocessing aided spatial modulation (PSM) is introduced for the downlink transmission in multi-user multiple-input multiple-output (MIMO) systems. In the proposed PSM scheme, the channel state information at transmitter (CSIT) is utilized to reduce the impact of the multi-user interference, while enabling successful signal detection at each user. We present a zero-forcing (ZF) preprocessing method that is designed in two stages. Moreover, this approach is extended to generalized preprocessing aided spatial modulation (GPSM), which significantly enhances the bandwidth efficiency of the proposed method. Since acquiring perfect CSIT is difficult in some scenarios, the proposed preprocessing technique is also adapted in presence of channel uncertainty. The simulation results indicate that the proposed PSM scheme outperforms the existing multi-user SM scenarios. Furthermore, the proposed scheme outperforms conventional multi-user MIMO scheme, while yielding satisfying performance in the case of erroneous channel estimation and low correlated channels.