{"ID":2824377,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2512.23506","arxiv_id":"2512.23506","title":"Affine-Projection Recovery of Continuous Angular Power Spectrum: Geometry and Resolution","abstract":"This paper considers recovering a continuous angular power spectrum (APS) from the channel covariance. Building on the projection-onto-linear-variety (PLV) algorithm, an affine-projection approach introduced by Miretti \\emph{et. al.}, we analyze PLV in a well-defined \\emph{weighted} Fourier-domain to emphasize its geometric interpretability. This yields an explicit fixed-dimensional trigonometric-polynomial representation and a closed-form solution via a positive-definite matrix, which directly implies uniqueness. We further establish an exact energy identity that yields the APS reconstruction error and leads to a sharp identifiability/resolution characterization: PLV achieves perfect recovery if and only if the ground-truth APS lies in the identified trigonometric-polynomial subspace; otherwise it returns the minimum-energy APS among all covariance-consistent spectra.","short_abstract":"This paper considers recovering a continuous angular power spectrum (APS) from the channel covariance. Building on the projection-onto-linear-variety (PLV) algorithm, an affine-projection approach introduced by Miretti \\emph{et. al.}, we analyze PLV in a well-defined \\emph{weighted} Fourier-domain to emphasize its geom...","url_abs":"https://arxiv.org/abs/2512.23506","url_pdf":"https://arxiv.org/pdf/2512.23506v1","authors":"[\"Shengsong Luo\",\"Ruilin Wu\",\"Chongbin Xu\",\"Junjie Ma\",\"Xiaojun Yuan\",\"Xin Wang\"]","published":"2025-12-29T14:46:36Z","proceeding":"cs.IT","tasks":"[\"cs.IT\",\"eess.SP\"]","methods":"[]","has_code":false}