Performance Analysis of SWIPT- Enabled Cooperative NOMA System with Partial Relay Selection

Recently, non-orthogonal multiple access (NOMA) and radio frequency (RF) energy harvesting (EH) techniques are applied in cooperative communication systems for 5G and beyond wireless communications. To exploit the benefits of the aforementioned techniques, we investigate the performance of a simultaneous wireless information and power transfer (SWIPT)-enabled cooperative NOMA system with decode-and-forward (DF) relaying technique. We consider a scenario, where a base station (BS) communicates with two users with the help of one EH relay, which is selected out of multiple relays using partial relay selection (PRS) scheme. The selected relay harvests energy through RF signals received from BS using a time-switching-based relaying (TSR) EH protocol. Furthermore, the relay utilizes the harvested energy from BS to forward the decoded information to the mobile users. The performance of the proposed system model is analyzed by deriving closed-form expressions for outage probability, ergodic capacity, energy efficiency, and overall system throughput over Rayleigh fading channels. Since perfect channel state information (CSI) and successive interference cancellation (SIC) are not practically possible at the receiver nodes in the proposed system model, we have also considered the effects of imperfect CSI and SIC on the system performance. Finally, Monte-Carlo simulations are presented to verify the correctness of the analytical expressions.