Error performance of cooperative relaying systems empowered by SWIPT and NOMA

Abstract

In this paper, we consider a cooperative relaying system (CRS) empowered by simultaneous wireless information power transfer (SWIPT) and non-orthogonal multiple access (NOMA) where SWIPT and NOMA are implemented for their energy and spectral efficiencies, respectively. We analyze error performance of the considered CRS-SWIPT-NOMA and derive exact closed-form average bit error probability (ABEP) over Nakagami-m fading channels which is perfectly-matched with computer simulations. The considered CRS-SWIPT-NOMA outperforms the benchmark (no energy harvesting) significantly which is very promising for green communications. Then, we discuss diversity order of the CRS-SWIPT-NOMA and, with extensive simulations, we revealed that it is equal to minimum shape parameter (i.e., m) between nodes. Lastly, we investigate the effects of SWIPT and NOMA parameters on the error performance and discuss the optimum parameters in terms of minimum ABEP. We also discuss the relay position to improve the performance of the CRS-SWIPT-NOMA.