Sub-optimal low-complexity detector for generalised quadrature spatial modulation

Abstract

Quadrature spatial modulation (QSM) is one of the recently emerging transmission schemes to improve the throughput of the multi-input multi-output systems. QSM transmits an M-ary complex symbol whose real and imaginary parts activate an antenna index independently thus provides an extra spatial dimension compared to conventional spatial modulation (SM). A generalised QSM (GQSM) transmission is considered in which a set of M-ary complex symbols activate multiple antennas to transmit their real and imaginary parts separately, which offers higher throughput in terms of bits per channel use (bpcu) than other SM techniques. A detector is proposed, ordering-based structured orthogonal matching pursuit for GQSM using compressive sensing (CS), which performs very close to the maximum likelihood detector with significantly lesser complexity. Also, the proposed algorithm performs superior to other CS-based detectors and offers a better trade-off between complexity and performance.