FQAM/FPSK modulation for spatial modulation systems

Spatial Modulation (SM) is a recently developed transmit technique, and it has attracted wide interests for it gains higher transmit rate than single-input-single-output (SISO) system and provides simpler transceiver structure and lower power consumption compared with traditional MIMO system. In this paper, we propose the spatial modulation systems with frequency and quadrature amplitude modulation (FQAM)/frequency and phase shift keying (FPSK), which combine frequency shift keying (FSK) and quadrature amplitude modulation (QAM)/phase shift keying (PSK). Simulation results show that the proposed scheme (i.e. FQAM/FPSK-SM) achieves significantly better bit error performance (BER) than traditional SM system and FQAM/FPSK system using maximum likelihood (ML) detector, and it can assign information flexibly among the constellation modulation, the index of the active antenna and the index of the active frequency. We also compare and analyze system performance and complexity of optimal detector and sub-optimal detector.