Performance analyses of intelligent reflecting surface aided downlink multi-user rate-splitting multiple access system for 6G applications

Abstract

The future wireless networks will handle extremely high data rates and fundamentally new applications, demanding a paradigm leap in wireless radio technology. The combination of rate-splitting multiple access (RSMA) and an intelligent reflecting surface (IRS) is an efficient way for improving the spectral/energy efficiency of next-generation wireless networks, such as 5G and beyond and 6G. In this paper, we propose an IRS-assisted downlink multi-user RSMA system towards 6G applications. Near users (NU) and cell edge users (CEU) are the two types of users considered in the proposed system, with NUs directly connected to the BS and CEUs connected via IRS. During transmission, the IRS acts as a relay and we investigate the performance of an IRS-aided RSMA system in terms of sum rate and outage probability under various NU and CEU scenarios. The novelty of the work is to derive the sum rate of the system model over Rayleigh and Rician fading channel we also derive the outage probability expression of the system for direct and indirect transmission to the CEUs and direct transmission to the NUs. Here we plot and analyzed the sum rate and outage probability results by varying the user power allocation, transmit power, transmit signal to noise ratio (SNR) ρB and other parameters. The results show that at 7dBm of transmit power, the NU achieves an outage probability greater than 10−1 and the CEU achieves an outage probability less than 10−2.