{"ID":2847124,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2511.01099","arxiv_id":"2511.01099","title":"On the Performance of Tri-Hybrid Beamforming Using Pinching Antennas","abstract":"The Pinching-Antenna System (PASS) reconfigures wireless channels through \\emph{pinching beamforming}, in which the active positions of pinching antennas (PAs) along dielectric waveguides are optimized to shape the radiation pattern. This article investigates the performance of PASS-enabled tri-hybrid beamforming, where pinched waveguides are integrated with a hybrid digital-analog beamformer to mitigate path loss and enhance spectral efficiency. The channel capacity of the proposed system is characterized by deriving the optimal tri-hybrid beamformer at both the digital and analog domains, as well as the optimal placement of PAs. Closed-form upper and lower bounds of the channel capacity are obtained, leading to a capacity scaling law with respect to the number of PAs. Numerical results verify the tightness of the derived bounds and demonstrate that applying PASS to tri-hybrid beamforming yields a significant performance gain over conventional hybrid beamforming under the same number of radio-frequency chains.","short_abstract":"The Pinching-Antenna System (PASS) reconfigures wireless channels through \\emph{pinching beamforming}, in which the active positions of pinching antennas (PAs) along dielectric waveguides are optimized to shape the radiation pattern. This article investigates the performance of PASS-enabled tri-hybrid beamforming, wher...","url_abs":"https://arxiv.org/abs/2511.01099","url_pdf":"https://arxiv.org/pdf/2511.01099v2","authors":"[\"Zhenqiao Cheng\",\"Chongjun Ouyang\",\"Nicola Marchetti\"]","published":"2025-11-02T22:29:17Z","proceeding":"eess.SP","tasks":"[\"eess.SP\"]","methods":"[]","has_code":false}