Passive Multi-Target Localization in RIS-Assisted WLAN Systems
摘要
This study investigates passive multi-target indoor localization in reconfigurable intelligent surface (RIS)-assisted wireless local area network (WLAN) systems. Unlike conventional methods that rely on the receiver’s spatial resolution, we propose a novel formulation that directly exploits the spatial resolution of the RIS for improved localization accuracy. To tackle the challenge of high-dimensional joint parameter estimation, we develop a low-complexity off-grid sparse representation model by applying geometric approximations and reformulating the problem into a coarse, non-uniform framework. This transformation enables efficient and accurate joint localization by fully leveraging signal sparsity. Moreover, we design a variational Bayesian algorithm for joint sparse signal recovery, which simultaneously estimates all target positions and incorporates a grid refinement strategy to enhance accuracy. Numerical results demonstrate the effectiveness and robustness of the proposed approach.