Joint Relay And Antenna Selection For Cognitive Radio-Inspired Non-Orthogonal Multiple Access

This paper investigates the joint relay and antenna selection strategy for amplify-and-forward (AF) cognitive radio-inspired non-orthogonal multiple access (CR-NOMA) systems. The outage performance is analyzed for the cooperative CRNOMA networks over Nakagami-m fading channels. The exact expression for the outage probability is derived in closed-form as well as the asymptotic expression. Based on the analytical results, the impacts of relay numbers, antenna numbers and fading parameters on outage performance are clearly revealed. Finally, simulation results demonstrate that CR-NOMA can meet different users' quality of service (QoS) requirements and achieve superior outage performance over NOMA with fixed power allocation (F-NOMA). Compared with orthogonal multiple access (OMA) relaying networks, CR-NOMA can achieve a significant performance gain and user fairness.