Performance Enhancement of Random Cognitive Radio Networks with Non-orthogonal Multiple Access

In this paper, a random cognitive radio networks schemes combined with Non-orthogonal Multiple Access (NOMA) is investigated. In the proposed protocol, relying on the channel gains, a secondary source selects two best secondary destinations to transmit the data. For performance evaluation and comparison, we derive exact and asymptotic closed-form expressions of outage probability (OP) over Rayleigh fading channel. Finally, Monte-Carlo simulations are performed to verify the theoretical results.