Movable Antenna-Enhanced Near-Field Flexible Beamforming: Performance Analysis and Optimization

Fuente: arXiv
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Autori principali: Yang, Shun, Wei, Xin, Su, Nianbing, Mei, Weidong, Chen, Zhi, Ning, Boyu
Natura: Preprint
Pubblicazione: 2026
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author Yang, Shun
Wei, Xin
Su, Nianbing
Mei, Weidong
Chen, Zhi
Ning, Boyu
author_facet Yang, Shun
Wei, Xin
Su, Nianbing
Mei, Weidong
Chen, Zhi
Ning, Boyu
contents As an emerging wireless communication technology, movable antennas (MAs) offer the ability to adjust the spatial correlation of steering vectors, enabling more flexible beamforming compared to fixed-position antennas (FPAs). In this paper, we investigate the use of MAs for two typical near-field beamforming scenarios: beam nulling and multi-beam forming. In the first scenario, we aim to jointly optimize the positions of multiple MAs and the beamforming vector to maximize the beam gain toward a desired direction while nulling interference toward multiple undesired directions. In the second scenario, the objective is to maximize the minimum beam gain among all the above directions. However, both problems are non-convex and challenging to solve optimally. To gain insights, we first analyze several special cases and show that, with proper positioning of the MAs, directing the beam toward a specific direction can lead to nulls or full gains in other directions in the two scenarios, respectively. For the general cases, we propose a discrete sampling method and an alternating optimization algorithm to obtain high-quality suboptimal solutions to the two formulated problems. Furthermore, considering the practical limitations in antenna positioning accuracy, we analyze the impact of position errors on the performance of the optimized beamforming and MA positions, by introducing a Taylor series approximation for the near-field beam gain at each target. Numerical results validate our theoretical findings and demonstrate the effectiveness of our proposed algorithms.
format Preprint
id arxiv_https___arxiv_org_abs_2601_17825
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Movable Antenna-Enhanced Near-Field Flexible Beamforming: Performance Analysis and Optimization
Yang, Shun
Wei, Xin
Su, Nianbing
Mei, Weidong
Chen, Zhi
Ning, Boyu
Signal Processing
As an emerging wireless communication technology, movable antennas (MAs) offer the ability to adjust the spatial correlation of steering vectors, enabling more flexible beamforming compared to fixed-position antennas (FPAs). In this paper, we investigate the use of MAs for two typical near-field beamforming scenarios: beam nulling and multi-beam forming. In the first scenario, we aim to jointly optimize the positions of multiple MAs and the beamforming vector to maximize the beam gain toward a desired direction while nulling interference toward multiple undesired directions. In the second scenario, the objective is to maximize the minimum beam gain among all the above directions. However, both problems are non-convex and challenging to solve optimally. To gain insights, we first analyze several special cases and show that, with proper positioning of the MAs, directing the beam toward a specific direction can lead to nulls or full gains in other directions in the two scenarios, respectively. For the general cases, we propose a discrete sampling method and an alternating optimization algorithm to obtain high-quality suboptimal solutions to the two formulated problems. Furthermore, considering the practical limitations in antenna positioning accuracy, we analyze the impact of position errors on the performance of the optimized beamforming and MA positions, by introducing a Taylor series approximation for the near-field beam gain at each target. Numerical results validate our theoretical findings and demonstrate the effectiveness of our proposed algorithms.
title Movable Antenna-Enhanced Near-Field Flexible Beamforming: Performance Analysis and Optimization
topic Signal Processing
url https://arxiv.org/abs/2601.17825