Improved High-Rate STBC-SM Schemes for Wireless MIMO Systems

This paper proposes improved high-rate Space-Time Block Coded Spatial Modulation (STBC-SM) schemes for 4 transmit antennas by applying the concept of Spatial Constellation (SC) introduced in [1] to the Alamouti's STBC in [2] and the Sezginer's STBC [3]. We concentrate on the design and optimization of SC codewords so that the proposed schemes achieve second order transmit diversity. Moreover, for 4 transmit antennas, we are able to construct 16 SC codewords, as compared to 4 SC codewords in [4] and [5], and to 8 SC codewords in [1]. Consequently, higher spectral efficiencies are achieved. Computer simulation shows that the proposed schemes outperform various existing STBC-SM schemes in different application scenarios.