{"ID":2874515,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2509.03980","arxiv_id":"2509.03980","title":"Approximate Message Passing for Multi-Preamble Detection in OTFS Random Access","abstract":"This article addresses the problem of multiple preamble detection in random access systems based on orthogonal time frequency space (OTFS) signaling. This challenge is formulated as a structured sparse recovery problem in the complex domain. To tackle it, the authors propose a new approximate message passing (AMP) algorithm that enforces double sparsity: the sparse selection of preambles and the inherent sparsity of OTFS signals in the delay-Doppler domain. From an algorithmic standpoint, the non-separable complex sparsity constraint necessitates a careful derivation and leads to the design of a novel AMP denoiser. Simulation results demonstrate that the proposed method achieves robust detection performance and delivers significant gains over state-of-the-art techniques.","short_abstract":"This article addresses the problem of multiple preamble detection in random access systems based on orthogonal time frequency space (OTFS) signaling. This challenge is formulated as a structured sparse recovery problem in the complex domain. To tackle it, the authors propose a new approximate message passing (AMP) algo...","url_abs":"https://arxiv.org/abs/2509.03980","url_pdf":"https://arxiv.org/pdf/2509.03980v1","authors":"[\"Alessandro Mirri\",\"Vishnu Teja Kunde\",\"Enrico Paolini\",\"Jean-Francois Chamberland\"]","published":"2025-09-04T08:07:38Z","proceeding":"eess.SP","tasks":"[\"eess.SP\"]","methods":"[]","has_code":false}