Performance Analysis of Cascaded RIS-Assisted Two-Way Wireless Communication System

In this letter, a cascaded reconfigurable intelligent surfaces (RIS)-assisted two-way communication system is proposed, and its performance is explored under $\kappa -\mu $ fading channels, supporting simultaneous information exchange between the transmitter and receiver. To more accurately reflect practical communication scenarios, the impacts of transceiver hardware impairments (HWI), phase errors, path loss, and loop interference (LI) are taken into account. Approximate closed-form expressions for the outage probability (OP) and ergodic capacity (EC) are derived, and the accuracy of the theoretical formulas is validated through Monte Carlo simulations. The results demonstrate that the effects of HWI, phase errors, path loss, and LI degrade the communication performance of the system. In addition, the EC of the proposed system is improved by approximately twice the one-way system, highlighting the significant advantage of two-way communication in enhancing spectral efficiency.