ABSTRACT One of the most important technologies for sixth‐generation (6G) wireless communication is the Intelligent reflecting surface (IRS), which provides intelligence, low power consumption, and reconfigurability. For 5G and beyond, nonorthogonal multiple access (NOMA) is a favorable technology for next‐generation wireless communication systems. To enhance the performance of upcoming wireless communication networks, IRS‐NOMA, a new hybrid technique, combines the benefits of IRS and NOMA. In this study, an IRS‐assisted NOMA network is investigated over the κ‐μ fading channel. The statistical channel model for the downlink IRS‐NOMA system is developed and validated through Monte Carlo simulations. Also, analytical expressions for the outage probability (OP) and average sum rate are also derived for both near and far users. Furthermore, the impact of performance factors such as imperfect successive interference cancellation (SIC), user pairing under different imperfect channel and SIC conditions, number of reflecting surfaces of IRS and imperfect channel estimation on the performance metrics is examined. It has been observed that a performance gain of 1.349 bits per channel use (BPCU) in terms of sum rate is achieved when the number of reflecting elements is increased from 1 to 10 at 5 dB SNR. It is also observed that pairing users in the six‐user IRS‐NOMA system with the most distinct channel conditions achieves a 5.77% gain at 5 dB SNR in terms of sum rate, as compared to pairing users with the smallest difference in their channel conditions.
Khan et al. (Thu,) studied this question.