Outage Performance of Partial Relay Selection in Underlay CR-NOMA Networks

This paper investigates the impact of partial relay selection scheme (PRSS) on cooperative underlay cognitive radio (CR) non-orthogonal multiple access (NOMA) networks. Decode-and-forward (DF) protocol is used at the selected relay to assist simultaneous transmission from the source node to destination users. Based on the above assumptions, we obtain the closed-form expressions of the outage probability (OP) for the secondary users. Moreover, the analytical results of this paper verify the impacts of relay node's number and power allocation (PA) on the system performance. Monte Carlo (MC) simulations validate the theoretical results.