{"ID":2882859,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2508.09882","arxiv_id":"2508.09882","title":"On Beamforming for Transmitter Location Privacy in MIMO Systems","abstract":"In this paper, we introduce a beamforming framework to ensure transmitter location privacy against sensing-capable MIMO receivers. We propose a novel privacy metric called the direction-of-arrival obfuscation power ratio (DoA-OPR) to design the transmit beamformer. The design approach reshapes the angular power distribution observed at the receiver so that a false direction appears dominant without nulling the line-of-sight (LoS) component. We derive closed-form bounds on the feasible range of DoA-OPR via generalized eigenvalue analysis and formulate an achievable rate-maximization problem under the DoA-OPR constraint. The resulting problem is non-convex but can be efficiently solved using semidefinite relaxation, eigenmode selection, and optimal power allocation. Numerical results demonstrate that the proposed DoA-OPR-based beamformer achieves a trade-off between location privacy and communication rate. The proposed design attains higher achievable rates than existing LoS-nulling approaches while maintaining comparable location privacy. A suboptimal design strategy is also proposed with reduced complexity. It achieves a near-optimal communication rate with a reduction of nearly 85%.","short_abstract":"In this paper, we introduce a beamforming framework to ensure transmitter location privacy against sensing-capable MIMO receivers. We propose a novel privacy metric called the direction-of-arrival obfuscation power ratio (DoA-OPR) to design the transmit beamformer. The design approach reshapes the angular power distrib...","url_abs":"https://arxiv.org/abs/2508.09882","url_pdf":"https://arxiv.org/pdf/2508.09882v2","authors":"[\"Umair Ali Khan\",\"Lester Ho\",\"Holger Claussen\",\"Mark F. Flanagan\",\"Chinmoy Kundu\"]","published":"2025-08-13T15:32:10Z","proceeding":"eess.SP","tasks":"[\"eess.SP\"]","methods":"[]","has_code":false}