Theory and application of reconfigurable intelligent surfaces with integrated sensing

One major challenge in achieving uninterrupted wireless communications with high data rate is the loss due to propagation environment, such as signal blockage by buildings or signal diffraction by various surfaces. To circumvent these issues, the technique of using reconfigurable intelligent surfaces (RIS) has been proposed. RIS can redirect reflected signals toward intended users, thus avoiding signal blockage, mitigating interference, or increasing security.

Engineering the desired propagation environment, however, requires knowledge about important parameters such as the directions of the users or transmitters to be available at the RIS. To address this need, this project will develop a new type of hybrid reconfigurable intelligent surfaces (HRIS). The HRIS will be designed to sense the incident waves on the entire surface, deduce relevant information, such as the directions of users and transmitters, and reconfigure their reflection patterns accordingly.

By developing the HRIS, this project paves the way for the implementation of a truly smart and autonomous propagation environment. This project also examines other opportunities that can be enabled by the HRIS to sense the environment with high spatial resolution, such as imaging objects for context-aware homes and buildings or threat detection. The research project is complemented by a comprehensive educational plan to engage graduate and undergraduate students in designing metasurfaces and HRIS, developing compressive sensing techniques, and devising intelligent electromagnetic environments.

This project also includes several undergraduate-led efforts where they will learn to use the HRIS to track devices and provide them with focused beams for wireless power transfer (WPT). The resulting adaptive WPT demonstrations will be used in interactive workshops on topics of electromagnetic research and emerging trends in wireless communications and sensing, as well as at outreach events.

This research project will outline the design of HRIS and experimentally demonstrate their utility in typical wireless communications settings. It will thus make innovative contributions including 1) the design of a novel metasurface that allows for reconfigurable reflection and sensing of the incident wave, 2) the development and experimental validation of novel algorithms for compressive sensing of the propagation environment with high spatial resolution using only a few receiving units, 3) a smart adaptive communications link where the HRIS detects the transmitter and users and transform its reflection patterns accordingly, and 4) development and experimental validation of novel imaging configurations where the scattered wireless communications signals (signals of opportunities) are collected by the HRIS and processed to retrieve reflectivity maps.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.