Spatial modulation: Performance evaluation in Nakagami fading channels

Multiple Input Multiple Output (MIMO) transmission systems have been proposed to increase the spectral efficiency of future wireless communications. However, simultaneous transmission on the same frequency from multiple transmitting antennas causes high interchannel interference (ICI). This significantly increases system complexity with increasing the number of transmitting antennas. Spatial modulation (SM) avoids ICI and the need of accurate time synchronization amongst antennas by making only one antenna active at any instant of time and employing the antenna index as additional source of information. In this paper, the performance of SM in a Nakagami fading environment is studied. Exact integral expressions for calculating the symbol error rate of multilevel Quadrature Amplitude Modulation (M-QAM) of SM in correlated and uncorrelated Nakagami fading channels are derived. The analytical and simulation results match closely over a wide range of SNR values.