Non-Orthogonal Multiple Access-assisted Cognitive Radio Networks: Performance Analysis

Non-Orthogonal Multiple Access (NOMA) is a prospective paradigm, which drastically improves spectral efficiency by permitting several users to partake concurrently the same transmission medium. Also, Cognitive Radio Networks (CRNs) considerably enhance spectral utilization efficiency by permitting unlicensed users to opportunistically transmit on frequency bands of licensed users subject to acceptable reliability of licensed users. Therefore, NOMA-assisted CRNs have attracted greatly interest from both academia and industry for attaining both high spectral efficiency and spectral utilization efficiency. Nonetheless, the outage performance of NOMA-assisted CRNs has not been analyzed thoroughly to gain insights and serve design guidelines. Towards this end, we firstly propose such an analysis by deriving precise explicit expressions of the outage probabilities of the far and near unlicensed receivers for these networks. Subsequently, the exactness of these expressions is corroborated extensively by computer simulations. Eventually, various results are supplied to demonstrate the outage probabilities in crucial system parameters.