On the Performance of Multi-User IRS-Assisted NOMA–ISABC Networks in the Presence of Interference

Abstract

To support Internet of Things (IoT) applications, next-generation networks are envisioned to provide both sensing functionality and low-power communications. This letter investigates the impact of co-channel interference (CCI) on a multi-user intelligent reconfigurable surface (IRS)-assisted non-orthogonal multiple access (NOMA) system with integrated sensing and backscatter communication (ISABC). Taking into account the effects of CCI signals on the communication users and the sensing receiver, as well as error propagation in successive interference cancellation (SIC), new closed-form expressions for communication performance, including ergodic rate, and sensing performance, including the probabilities of false alarm and detection, are developed. The analytical results are validated through Monte Carlo simulations. Numerical results demonstrate that CCI degrades both communication and sensing performance, which can be alleviated by increasing the number of reflecting elements and collected samples. Moreover, to gain deeper insights, asymptotic analysis is also obtained to evaluate the system performance. The effects of imperfect SIC and backscattered signals on the communication rate are also analyzed.