Performance Analysis and Evaluation of Underlay Two-Way Cooperative Networks with NOMA

In this paper, we investigate two-way decode-and-forward scheme with non-orthogonal multiple access (NOMA) in underlay cognitive networks to increase efficiency of spectrum utilization as well as requirements of future networks. Secondary users communicate with each other via a secondary relay to decode and forward signal using the NOMA technology. We analyze and evaluate system performance in terms of outage probabilities with Rayleigh fading channels. The theoretical analyses are exactly validated by the Monte Carlo simulation method. The analysis and simulation results show that the system performance is improved by higher interference constraint thresholds and by closer locations to the secondary users of the cooperative relay.