Outage Analysis of NOMA Exploited Coordinated Direct and Relay assisted Uplink Transmission

An uplink Non-orthogonal multiple access exploiting coordinated direct and relay aided communication protocol named as UNOMA is proposed, where a user having better channel experience directly communicates with the base station and a user having comparatively bad channel experience communicates by the assistance of a half-duplex decode-and-forward relay. Under the considerations of perfect and imperfect successive interference cancellations (SICs), the outage probability (OP) of UNOMA is analysed over Rayleigh fading channels. The effect of different physical parameters on the OP is investigated. To justify the analytical results, Monte-Carlo simulations are provided that verifies the correctness under both imperfect and perfect SICs. Finally, the OP of the UNOMA is compared with the traditional uplink orthogonal multiple access (UOMA) scheme that demonstrates the advantage of UNOMA over UOMA conditioned on the system parameters.