Space Time Block Coding and Structured Multiplexing for Quadrature Spatial Modulation

Massive multiple-input multiple-output (mMIMO) technology is emerging as a pragmatic approach to guarantee tremendous data traffic for future wireless communication systems. In this paper, a transmission scheme described as a space-time block coded structured quadrature spatial modulation (STBC-SQSM) for the mMIMO system is proposed. The STBC-SQSM scheme guarantees the diversity benefits of the STBC system. Moreover, the SQSM symbols take over the conventional STBC constellation points to convey additional information bits by antenna indices rather than individually by STBC blocks. Besides, it requires only a limited number of radio frequency (RF) chains despite the enormous data rate achieved by employing spatial multiplexing of multiple QSM symbols. Further, the proposed system proposes a structured Bayesian compressive sensing (S-BCS) and a structured multipath orthogonal matching pursuit (S-mOMP) based detectors with significantly reduced computational complexity. The simulation results confirm that the proposed scheme renders a more beneficial bit error rate (BER) performance and spectral gain than the existing systems.