Research On Spatial Modulation

Spatial modulation (SM) is an emerging multiple-input multiple-output (MIMO)spatial multiplexing technique. For its single radio-frequency transmission characteristic,the inter-antenna synchronization can be avoided at the transmitter, and only simplesingle-stream detector is needed at the receiver. Moreover, spatial modulation conveyspart of its information implicitly by passive antennas, thus can achieve higher energyefficiency than conventional MIMO techniques. Because of these advantages, SM hasbeen researched extensively in the literature.In this paper, the capacity of SM is first studied, based on which the performance ofSM and the other MIMO schemes is compared. And the communication scenario wherethe SM achieves higher capacity is given. Then, the achievable information rate of SMwith constrained input is calculated. Based on the extrinsic information transfer charttechnique, the degree distribution of the irregular low-density parity-check code for SMis optimized to approach the information theoretical limit. Finally, in order to improve thespectral efficiency and provide transmit diversity of the SM scheme, two novelmultiple-antenna schemes where the SM is combined with the space-time block coding(STBC) and the vertical Bell Laboratories layered space-time (VBLAST), respectively,are presented. From the analytic and simulated results, the proposed SM-STBC andSM-VBLAST schemes can achieve transmit diversity gain and higher spectral efficiency,respectively, compared with the conventional SM scheme. Furthermore, both theproposed schemes are more robust to the transmit channel correlation than theconventional SM scheme.