Abstract
Reconfigurable intelligent surface (RIS)–aided localization in the radiating near-field requires range-aware spherical-wave models, which inherently couple angles and range and thus complicate accurate 3D positioning. Using the Fresnel approximation, we show that the RIS response can be expressed as the element-wise product of a 2D far-field steering vector and a range-dependent quadratic-phase chirp. By modeling these chirp components within a low-dimensional subspace, we reformulate the joint recovery of azimuth, elevation, and range under a 2D super-resolution framework, resulting in a 2D atomic norm minimization (2D-ANM) problem. Solving this via a semi-definite program (SDP) yields gridless azimuth-elevation estimation and high-accuracy range estimation. Simulations demonstrate accurate 3D localization and enhanced robustness of the proposed scheme, compared with subspace and compressive sensing methods.
| Original language | English |
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| Title of host publication | 2026 IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM) (http://arxiv.org/abs/2509.18774) |
| Publication status | Submitted - 18 Sept 2025 |