Outage Performance of NOMA-based DF Relay Sharing Networks over Nakagami-m Fading Channels

In this paper, we study the performance of cooperative non-orthogonal multiple access (C-NOMA) spectrum-sharing networks with a decode-and-forward (DF) relay over Nakagami-m Fading Channels. Two sources are paired to perform NOMA and transmit information to two paired destinations in the opposite direction via one shared half-duplex (HD) DF relay. New closed-form expressions for the outage probability, the asymptotic outage probability and the system throughput, as performance metrics, are derived over such a channel fading model. Simulation results investigate the correctness of our derivations and demonstrate the impact of the fading parameters and average channel coefficients on the performance.