Outage analysis of cognitive non‐orthogonal multiple access downlink system with secondary source selection in Nakagami‐m fading environment

Abstract

Summary Cognitive inspired non‐orthogonal multiple access (Cognitive‐NOMA) technique allows multiple primary and secondary users to utilize the same time and frequency resources to explore the reliability and spectral efficient requirements of 5G communication networks. In this paper Cognitive‐NOMA downlink system with multiple secondary source (SS) nodes is proposed. An optimal SS node is selected based on the signal to interference plus noise ratio (SINR) requirements of both near and far primary users and the secondary user node. Each optimal SS node incorporates simultaneous wireless information and power transfer (SWIPT) and full‐duplex technique to harvest energy and transceiver operation. Analytical outage probability expressions of the proposed system are derived over Nakagami‐m fading environment with the assumption that SS transmission links are correlated. Numerical results infer that the outage performance of the proposed system depends on the number of SS nodes, self‐interference at the SS node, and the SINR constraint for the selection of optimal SS node.