Standalone Intelligent Reflecting Surface With Automatic Update of Phase-Shift Switching Schedule for Improved Communication and Localization

An intelligent reflecting surface (IRS) allows to control signal propagation and may substantially improve the energy utilization efficiency for sixth-generation mobile communications. We previously proposed a wireless communication system using a standalone IRS that solves two problems: 1) channel estimation overhead for the reflective elements and 2) shared IRS use by multiple wireless network operators. The standalone IRS sweeps the reflected beam by periodically switching the phase shift to cover a wide area. However, when the user area is limited, signals with a phase shift that is not reflected in the user direction are lost. Hence, we propose a method for the standalone IRS to automatically detect useless phase shifts and update the phase-shift switching schedule according to the communication environment. Furthermore, we propose an indoor localization method that supports the automatic update for potential applications such as smart factories and smart homes, in which both communication and the localization of user equipment are required. Simulation results show that the proposed method improves the communication efficiency and localization accuracy by properly updating the phase-shift switching schedule.