RIS-Assisted Beamfocusing in Near-Field IoT Communication Systems: A Transformer-Based Approach

Fuente: arXiv
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Autori principali: Zhou, Quan, Zhao, Jingjing, Cai, Kaiquan, Zhu, Yanbo
Natura: Preprint
Pubblicazione: 2025
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author Zhou, Quan
Zhao, Jingjing
Cai, Kaiquan
Zhu, Yanbo
author_facet Zhou, Quan
Zhao, Jingjing
Cai, Kaiquan
Zhu, Yanbo
contents The massive number of antennas in extremely large aperture array (ELAA) systems shifts the propagation regime of signals in internet of things (IoT) communication systems towards near-field spherical wave propagation. We propose a reconfigurable intelligent surfaces (RIS)-assisted beamfocusing mechanism, where the design of the two-dimensional beam codebook that contains both the angular and distance domains is challenging. To address this issue, we introduce a novel Transformer-based two-stage beam training algorithm, which includes the coarse and fine search phases. The proposed mechanism provides a fine-grained codebook with enhanced spatial resolution, enabling precise beamfocusing. Specifically, in the first stage, the beam training is performed to estimate the approximate location of the device by using a simple codebook, determining whether it is within the beamfocusing range (BFR) or the none-beamfocusing range (NBFR). In the second stage, by using a more precise codebook, a fine-grained beam search strategy is conducted. Experimental results unveil that the precision of the RIS-assisted beamfocusing is greatly improved. The proposed method achieves beam selection accuracy up to 97% at signal-to-noise ratio (SNR) of 20 dB, and improves 10% to 50% over the baseline method at different SNRs.
format Preprint
id arxiv_https___arxiv_org_abs_2504_12889
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle RIS-Assisted Beamfocusing in Near-Field IoT Communication Systems: A Transformer-Based Approach
Zhou, Quan
Zhao, Jingjing
Cai, Kaiquan
Zhu, Yanbo
Signal Processing
Systems and Control
The massive number of antennas in extremely large aperture array (ELAA) systems shifts the propagation regime of signals in internet of things (IoT) communication systems towards near-field spherical wave propagation. We propose a reconfigurable intelligent surfaces (RIS)-assisted beamfocusing mechanism, where the design of the two-dimensional beam codebook that contains both the angular and distance domains is challenging. To address this issue, we introduce a novel Transformer-based two-stage beam training algorithm, which includes the coarse and fine search phases. The proposed mechanism provides a fine-grained codebook with enhanced spatial resolution, enabling precise beamfocusing. Specifically, in the first stage, the beam training is performed to estimate the approximate location of the device by using a simple codebook, determining whether it is within the beamfocusing range (BFR) or the none-beamfocusing range (NBFR). In the second stage, by using a more precise codebook, a fine-grained beam search strategy is conducted. Experimental results unveil that the precision of the RIS-assisted beamfocusing is greatly improved. The proposed method achieves beam selection accuracy up to 97% at signal-to-noise ratio (SNR) of 20 dB, and improves 10% to 50% over the baseline method at different SNRs.
title RIS-Assisted Beamfocusing in Near-Field IoT Communication Systems: A Transformer-Based Approach
topic Signal Processing
Systems and Control
url https://arxiv.org/abs/2504.12889