Performance Analysis of Cooperative Underlay NOMA-Assisted Cognitive Radio Networks

This paper analyzes the outage performance of the cooperative underlay NOMA-based cognitive radio (CR) network with the proposed channel-dependent interference threshold constraint (ch-ITC) scheme. Unlike the conventional fixed interference threshold constraint (f-ITC) scheme, to improve the performance of the secondary network (SN), the proposed channel-dependent ITC scheme imposes the transmit power constraint dynamically on SN that depends on the channel conditions of the primary wireless link. The outage probability expressions are derived to evaluate the performance of the underlay CR network, and the results reveal that the ch-ITC scheme performs better than the f-ITC scheme.