Reconfigurable Intelligent Surface Aided Wireless Imaging with Ring-Type Codebook

The sixth-generation wireless system (6G) is poised to incorporate sensing capability with communication, serving as a foundational infrastructure to facilitate emerging usage scenarios. Meanwhile, reconfigurable intelligent surface (RIS), as an innovative network deployment device, has emerged as a promising technology within the 6G radio network topology, offering a large array size at low cost and power consumption. This paper introduces RIS to further enhance high-resolution wireless imaging alongside typical communication functionalities, implemented by a ring-type codebook (RTC) suitable for near-field beam focusing and a back projection (BP) algorithm for real-aperture imaging. The near-field beam generated using RTC can offer additional range-dimension resolution capability and enable the system to dynamically adjust the granularity of beam scanning based on the different use case requirements. Numerical simulation results are provided to substantiate the viability of the proposed RIS-aided wireless imaging scheme, showcasing its ability to facilitate centimeter-level two-dimensional (2D) wireless imaging and provide additional range-dimension resolution capability for a narrowband system.