Performance evaluation of an IRS-assisted NOMA communication system with two-way relaying

Abstract

Intelligent Reflecting Surfaces (IRS) have emerged as a key enabling technology for B5G/6G systems which can smartly reconfigure the changing wireless environment. This study addresses key B5G network use cases like massive device connectivity and enhanced urban coverage, ideal for smart cities and large-scale IoT. Integrating an IRS into a non-orthogonal multiple access (NOMA) based two-way relay system reduces outage probability (OP), boosts ergodic capacity (EC), and tackles challenges like spectrum scarcity, energy efficiency, and the growing demand for reliable connectivity in densely populated environments. In this work, a novel NOMA communication system model assisted by a relay and an IRS has been analyzed in both uplink and downlink scenarios. The analytical expression for the outage probability (OP) of the relay-IRS-user link with new channel characteristics and Nakagami-m fading has been derived. This work also presents an analysis of the range of reflective elements required to ensure the minimum quality of service (QoS) for the far user. The system's ergodic capacity (EC) has also been analyzed. Finally, simulation results of outage probability (OP) and ergodic capacity (EC) have been presented. The results demonstrate that incorporating an IRS into the system model significantly improves performance.