Outage Probability Analysis for Relay Networks Combined with RIS-NOMA Systems

This paper explores the use of the non-orthogonal multiple access (NOMA) method for a two-user downlink relay network combined with reconfigurable intelligent surfaces (RISs). The network's performance is analyzed under the influence of relay and RIS techniques. Closed-form formulas for the outage probability (OP) of the two users are derived. Monte Carlo simulations are employed to confirm the accuracy of the analytical OP results. The results demonstrate that RIS integration greatly enhances performance, and relay placement, especially in terms of distance, has a significant impact on system performance. Additionally, the distribution of power to users through the NOMA approach highlights its effect on system efficiency.