Reconfigurable intelligent surface (RIS)-assisted wireless communications with a virtual reality (VR) case study
Tianrui Chen, Minglei You, Yangyishi Zhang, James Talbot, Fabrizio De Paolis, Fraser A. Burton, Gabriele Gradoni · IET conference proceedings. · 2024
Reconfigurable intelligent surface (RIS)/intelligent reflecting surface (IRS) has become a low-cost and effective technique to enhance system performance in wireless communications by adjusting phase shifts of its reflecting elements. However, RIS optimization typically entails the consideration of a substantial number of elements, thereby resulting in an expansive search space. Hence, it is difficult to solve the RIS phase shift design problem considering practical applications. This paper introduces a cross-entropy (CE) optimization method for binary RIS phase shifts which does not require channel estimation and only collects the end user’s performance such as received signal-to-noise ratio (SNR) and signal strength. Hence, this method is friendly to implement in real-world applications. The performance of the CE algorithm for RIS optimization is evaluated via two experimental case studies including a general wireless communication system and a special case of wireless virtual reality (VR) system. Experimental results demonstrate great advantages achieved by deploying RIS with CE algorithm in wireless networks such as improved SNR, channel hardening effect, and VR user experience compared to benchmark solutions.