A novel spatial modulation using MIMO spatial multiplexing

In this paper we propose a new Multiple-Input Multiple-Output (MIMO) transmission scheme that combines the generalised spatial modulation (GSM) with MIMO spatial multiplexing technique. Unlike the GSM which uses N_A active antennas to transmit the same symbol, the proposed scheme uses the N_A antennas to transmit different symbols simultaneously, which leads to increase the spectral efficiency of the system. An optimal detector is used at the receiver to jointly estimate the transmitted symbols as well as the index of active antennas combination. However, the optimal detector suffers from a high computational complexity. To solve this problem we propose a suboptimal detector which is based on a zero forcing detector. The performance of the proposed scheme is evaluated in an uncorrelated flat fading channel and compared with the optimal spatial modulation and vertical Bell Labs layered space-time.