Visually Steered Reconfigurable Intelligent Surface-Assisted Mobile Communications

This letter proposes a novel, visually steered Reconfigurable Intelligent Surface (RIS) beam tracking method to enable rapid beam steering actions for high-mobility users. The approach utilizes advanced machine vision algorithms driven by artificial intelligence models, incorporating a specially designed 2-bit phase-quantized reflective metasurface and an embedded system control module. In this architecture, the RIS maintains line-of-sight visibility to both the base station and user, while the base station and user themselves remain in a non-line-of-sight configuration. Positioning the vision sensor at the RIS offers comprehensive environmental awareness, facilitating real-time user localization and motion prediction capabilities that are unattainable at either the transmitter or the user. The RIS dynamically updates codebooks to maintain stable links between transmitter and user without relying on feedback. Experiments confirm that the system achieves milliseconds-level tracking and reliable communication, offering a low-overhead solution for highly dynamic scenarios.