Energy-efficient spatial modulation in massive MIMO systems by means of compressive sensing

In this paper we propose a spatial modulation (SM) technique with improved energy efficiency (EE) for the multiple access channel (MAC) with a large number of antennas. The proposed scheme builds upon compressive sensing (CS) and accounts for the sparsity and structure of the signals transmitted via SM in multi-user scenarios to further improve the performance and reduce the complexity of linear detectors. In particular, the proposed technique incorporates additional prior knowledge to conventional CS-based approaches by exploiting the existence of a maximum number of active antennas per user when SM transmission is used in the MAC. The results presented in this paper show that the proposed algorithm offers both a) reduced complexity and b) improved performance compared to conventional CS and linear detection strategies and also allow us to determine the conditions under which the use of SM systems in the MAC is beneficial from an EE point of view.