Outage performance of the downlink noma relay networks with RF energy harvesting and buffer aided relay

In this paper, we investigate performance of a decode-and-forward Non-Orthogonal Multiple Access (NOMA) relay system using Simultaneous Information and Power Transfer (SWIPT). In the considered system a source node transmits data in the downlink simultaneously to two destination nodes via an energy-harvesting relay node. In order to cope with fading channels the relay is assumed to have an infinite capacity buffer to store data if the transmission link is in outage. We analyze outage performance of the system and obtain the closed-form expressions for the system outage probability for two cases, i.e. the relay is equipped and not equipped with the buffer. Numerical results are provided to demonstrate the merit of using the buffer-aided relay. © 2019, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.