Low-complexity EDAS and low-complexity detection scheme for MPSK spatial modulation

Euclidean-distance antenna selection (EDAS) is an effective transmit AS technique for spatial modulation (SM). This study presents a low-complexity (LC) EDAS scheme for the M-ary phase shift keying (MPSK) SM. The LC-EDAS for MPSK SM (LC-MPSK-EDAS) is achieved by exploiting the rotational symmetry of the MPSK constellation and using singular value decomposition (SVD_EDAS) for factorisation of the modified channel matrix. A further reduction in complexity is achieved by eliminating the process of conditioning on elements of the MPSK symbol set. The complexity of the proposed scheme is independent of the order M of MPSK. Also, in this study, an LC near maximum likelihood (ML) detection scheme for MPSK SM systems, signal vector-based detection (SVD), is implemented. Though this scheme provides poor results when using the M-ary quadrature amplitude modulation constellation, it is found that the error performance of this scheme for MPSK constellations has very near ML results. The simulation results show that even at high signal-to-noise values this scheme maintains near ML performance. To support the results, the closed-form expression of the bit error rate for the MPSK constellation is derived.