MIMO Cooperative Spatial Modulation Systems

In this work, we propose novel cooperative spatial modulation (SM) systems with two main relaying techniques (amplify-and-forward, AF, and decode-and-forward, DF) where all nodes have multiple transmit and/or receive antennas. Most of the studies in the literature of cooperative SM systems, which combine the advantages of cooperative communications and SM systems, consider only the space shift keying (SSK) scheme with single receive/transmit antenna at relay and destination. Since the error performance of SM highly depends on the number of receive antennas and more flexible cooperative communications systems can be obtained by using SM with multiple antennas, it is essential to investigate multi-antenna cooperative SM systems. We derive analytical expressions of the average bit error probability (ABEP) for both the newly proposed cooperative SM-DF and cooperative SM-AF systems and validate with the computer simulation results. Furthermore, we present the bit error rate (BER) comparison of considered systems with classical M-PSK/QAM cooperative systems. Computer simulation results indicate that multiple antennas cooperative SM systems provide better error performance than classical cooperative systems for both relaying techniques.