On the Performance of Multi‐User CoNOMA With Practical Constraints

ABSTRACT In this paper, we present a cooperative non‐orthogonal multiple access (CoNOMA) communication system featuring two source users, two destination users, and a decode‐and‐forward relay. Using a single relay, both sources communicate to their respective destination using the NOMA scheme. Further, to improve the user's performance, both the direct and the relayed links at the destination are combined using the maximal ratio combining technique. To assess the robustness of our proposed framework, we formulate mathematical equations for the outage probability of the end users. To consider a more realistic scenario, practical constraints like hardware impairments (HI), imperfect channel state information (imCSI), and imperfect successive interference cancellation (imSIC) are considered at the destination node. We have presented the proposed system's average bit error rate performance to prove its effectiveness over existing systems. The analytical results have been validated through Monte Carlo simulations. Our work contributes to advancing the understanding and reliability of cooperative NOMA systems, offering insights that can be pivotal for designing future communication networks.