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arXiv · 2311.15292

Active-Sensing-Based Beam Alignment for Near Field MIMO Communications

Hao Jiang·Zhaolin Wang·Yuanwei Liu
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Abstract

An active-sensing-based learning algorithm is proposed to solve the near-field beam alignment problem with the aid of wavenumber-domain transform matrices (WTMs). Specifically, WTMs can transform the antenna-domain channel into a sparse representation in the wavenumber domain. The dimensions of WTMs can be further reduced by exploiting the dominance of line-of-sight (LoS) links. By employing these lower-dimensional WTMs as mapping functions, the active-sensing-based algorithm is executed in the wavenumber domain, resulting in an acceleration of convergence. Compared with the codebook-based beam alignment methods, the proposed method finds the optimal beam pair in a ping-pong fashion, thus avoiding high training overheads caused by beam sweeping. Finally, the numerical results validate the effectiveness of the proposed method.

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Hao Jiang, Zhaolin Wang, Yuanwei Liu. 2023-11-26. Active-Sensing-Based Beam Alignment for Near Field MIMO Communications. https://arxiv.org/abs/2311.15292

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