Generalized Space-Time Block Coded Quadrature Spatial Modulation

Abstract

Recently, quadrature spatial modulation (QSM) has been proposed for MIMO communication systems. It introduced to enhance the overall throughput of conventional spatial modulation (SM) techniques by creating an extra modulation spatial dimension. Here, a novel structuring scheme is proposed, that is called space-time block coded quadrature spatial modulation (STBC QSM). The paper includes an enhancement of the conventional QSM to the STBCs to achieve transmit-diversity gain that QSM does not offer. In addition, it achieves higher spectral efficiency compared to the space-time block coded spatial modulation (STBC-SM). This is because of an additional modulation dimensions (space and time) that are created, which allows for a transmitting diversity and multiplexing gains. This structuring scheme is based on Alamouti’s STBC code, but can be extended to other STBC codes using the scheme proposed. Both the diversity and complexity of the proposed design is analyzed and discussed. Simulation results show the effectiveness of STBC-QSM proposed compared to other state-of-art SM schemes, like conventional QSM and STBC-SM , which also corroborate the theoretical ones.