Work

Beyond Diagonal Reconfigurable Intelligent Surface Enabled Sensing: Cramér-Rao Bound Optimization

Year: 2025

Type: article

Abstract: Recently, beyond diagonal reconfigurable intelligent surface (BD-RIS) has emerged as a more flexible solution to engineer the wireless propagation channels, thanks to its non-diagonal reflecting matrix. Although the gain of the BD-RIS over the conventional RIS in communication has been revealed in many works, its gain in 6G sensing is still unknown. This motivates us to study the BD-RIS assisted sensing in this letter. Specifically, we derive the Cramér-Rao bound (CRB) for estimating the angle-of-arrival (AOA) from the target to the BD-RIS under the constraint that the BD-RIS scattering matrix is unitary. To minimize the CRB, we develop an optimization scheme based on an adaptive Riemannian steepest ascent algorithm that can satisfy the non-convex unitary constraint. Numerical results demonstrate that the proposed BD-RIS-assisted target localization method achieves superior sensing performance.

Source: IEEE Wireless Communications Letters

DOI: 10.1109/lwc.2025.3599590

Authors: Xiaoqi Zhang, Liang Liu, Shuowen Zhang, Haijun Zhang

Institutions: Hong Kong Polytechnic University, University of Science and Technology Beijing

Language: English

Topic: Advanced Wireless Communication Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funder: National Natural Science Foundation of China

Award: G7459745449