Transmit antenna grouping quadrature spatial modulation for MIMO systems

Abstract

With quadrature spatial modulation (QSM), an innovative and effective signaling technique for multiple-input multiple-output (MIMO) systems, index modulation is performed by activating one or two antennas at each time interval. However, for large-scale MIMO systems, it has been observed that QSM is limited in providing high spectral efficiency, which is a requirement of next generation communication systems. In order to increase spectral efficiency, a transmit antenna grouping quadrature spatial modulation (TAG-QSM) system model, which aims to increase the number of bits transmitted by antenna indexing, is proposed in this study. In the proposed system, transmitting antennas are divided into groups such that there are equal number of antennas in each group, and a certain number of antenna groups are determined separately for the real and virtual parts of the transmitted symbol. Then, separate antenna indices are determined for the transmission of the real and imaginary parts of the signal from the specified groups. After the TAG-QSM system model is introduced, the average bit error probability (ABEP) analysis of the system has been made. In addition, it has been shown by Monte Carlo simulations that the TAG-QSM system model achieves better error performance than parallel QSM (PQSM) and classical QSM systems in the literature for the same spectral efficiency with the same number of transmitter and receiver antennas.