On Partitioning Enabled IRS-Assisted Co-Operative NOMA with Mode Switching

This paper investigates a partition-based intelli-gent reflective surface (IRS) aided two-user cooperative non-orthogonal multiple access (C-NOMA) framework where the source communicates with the near user (NU) and the far user (FU). Based on feedback bits from the users, intelligent mode switching among non-orthogonal multiple access (NOMA), orthogonal multiple access (OMA), and C-NOMA is performed to ensure that NU does not compromise its performance while cooperating with FU. Further, the IRS surface is partitioned into two subsurfaces to ensure a fair quality of service at both users. The choice of IRS partitioning is also varied in accordance to the transmission modes. Considering mode switching, we derive the closed-form expressions for the throughput of both NU and FU. It is also demonstrated that the IRS-assisted network with opportunistic mode switching ensures higher throughput in comparison to the C-NOMA framework without incorporating IRS. Monte Carlo simulations validate the derived analytical expressions.