Performance Analysis of Cooperative Spatial Modulation with Multiple-Antennas at Relay

Spatial modulation (SM) is a novel and promising approach that has been introduced as an alternative to classical multiple-input multiple-output (MIMO) spatial multiplexing techniques. Cooperative communications, on the other hand, provides additional diversity gains and high data rates by improving coverage. Combining the advantages of SM and cooperative communications would then further improve efficiency. Most of the studies in the literature of cooperative SM systems consider the space shift keying (SSK) modulation, which is a special case of SM, and single receive/transmit antenna relay (R) and destination (D). In this work, we investigate the average bit error probability (ABEP) of a decode-and-forward (DF) cooperative SM system where all nodes have multiple transmit and/or receive antennas which has not been studied before. It is shown that the derived analytical expressions for the ABEP are in close match with the computer simulation results. Furthermore, it is demonstrated that the cooperative SM scheme provides 4 dB SNR gain compared to classical M-ary modulated cooperative systems.