Performance Analysis of Spatial Modulation Aided NOMA With Full-Duplex Relay

A spatial modulation aided non-orthogonal multiple access with full-duplex relay (SM-NOMA-FDR) scheme is proposed for the coordinated direct and relay transmission in this paper. Specifically, the signal of the near user is mapped to an $M$-ary modulated symbol and the signal of the far user is mapped to an SM symbol. The base station first transmits signals to the near user and relay via SM-NOMA, and then the relay decodes and retransmits the signal of the far user. An SM-assisted FDR is used in this scheme to improve the spectral efficiency while reducing energy consumption and making full use of the antenna resources at the relay, since SM only activates one antenna in each transmission. We derive the ergodic capacity and bit error rate of the proposed scheme over independent Rayleigh fading channels. Numerical results validate the accuracy of the theoretical analysis and show the superior performance of the proposed SM-NOMA-FDR scheme.