Transmission Design and Performance Analysis for a Cognitive NOMA-Based Relay Sharing Network

In this paper, we consider a non-orthogonal multiple access (NOMA)-based relay sharing scheme in cognitive radio network, in which the relay in the secondary network (SN) is asked to assist in the transmission of the primary network (PN). To guarantee the quality of service (QoS) of primary transmission and simultaneously minimize the outage probability (OP) of SN, dynamic power allocation is carried out. To characterize the performance of this scheme, we derive the OPs of both PN and SN. To gain more insights, the corresponding asymptotic results at high signal-to-noise ratio are developed as well. Finally, numerical simulations verify the accuracy of our derived results and show that our proposed scheme achieves superior outage performance than other benchmark schemes.