Performance evaluation of precoding in spatial modulation OFDM on a LTE channel

Multi-user MIMO downlink systems with one base station and many users have attracted the research attention. Precoding algorithms, which uses the channel state information (CSI) to process the transmit signal, have been used to pre-eliminate the spatial interference among different users. In this paper, we explore several precoding methods in the spatial modulation (SM) combined orthogonal frequency division multiplexing (SM-OFDM) to achieve good performance on a Long Term Evolution (LTE) channel. Channel inversion methods are introduced to SM scheme. Furthermore, we proposed a specified block diagonalization precoding method for this particular transmit antenna scheme. For assessment purposes, the performance results of SM-OFDM systems are compared with the popular Alamouti coded OFDM systems and vertical Bell Labs layered space-time (V-BLAST) OFDM systems. Simulation results show that SM based systems achieved better performance in some situations.