Wavenumber-Domain Near-Field Channel Estimation: Beyond the Fresnel Bound

Fuente: arXiv
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Autores principales: Guo, Xufeng, Chen, Yuanbin, Wang, Ying, Wang, Zhaocheng, Yuen, Chau
Formato: Preprint
Publicado: 2024
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author Guo, Xufeng
Chen, Yuanbin
Wang, Ying
Wang, Zhaocheng
Yuen, Chau
author_facet Guo, Xufeng
Chen, Yuanbin
Wang, Ying
Wang, Zhaocheng
Yuen, Chau
contents In the near-field context, the Fresnel approximation is typically employed to mathematically represent solvable functions of spherical waves. However, these efforts may fail to take into account the significant increase in the lower limit of the Fresnel approximation, known as the Fresnel distance. The lower bound of the Fresnel approximation imposes a constraint that becomes more pronounced as the array size grows. Beyond this constraint, the validity of the Fresnel approximation is broken. As a potential solution, the wavenumber-domain paradigm characterizes the spherical wave using a spectrum composed of a series of linear orthogonal bases. However, this approach falls short of covering the effects of the array geometry, especially when using Gaussian-mixed-model (GMM)-based von Mises-Fisher distributions to approximate all spectra. To fill this gap, this paper introduces a novel wavenumber-domain ellipse fitting (WDEF) method to tackle these challenges. Particularly, the channel is accurately estimated in the near-field region, by maximizing the closed-form likelihood function of the wavenumber-domain spectrum conditioned on the scatterers' geometric parameters. Simulation results are provided to demonstrate the robustness of the proposed scheme against both the distance and angles of arrival.
format Preprint
id arxiv_https___arxiv_org_abs_2409_10123
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Wavenumber-Domain Near-Field Channel Estimation: Beyond the Fresnel Bound
Guo, Xufeng
Chen, Yuanbin
Wang, Ying
Wang, Zhaocheng
Yuen, Chau
Signal Processing
Information Theory
In the near-field context, the Fresnel approximation is typically employed to mathematically represent solvable functions of spherical waves. However, these efforts may fail to take into account the significant increase in the lower limit of the Fresnel approximation, known as the Fresnel distance. The lower bound of the Fresnel approximation imposes a constraint that becomes more pronounced as the array size grows. Beyond this constraint, the validity of the Fresnel approximation is broken. As a potential solution, the wavenumber-domain paradigm characterizes the spherical wave using a spectrum composed of a series of linear orthogonal bases. However, this approach falls short of covering the effects of the array geometry, especially when using Gaussian-mixed-model (GMM)-based von Mises-Fisher distributions to approximate all spectra. To fill this gap, this paper introduces a novel wavenumber-domain ellipse fitting (WDEF) method to tackle these challenges. Particularly, the channel is accurately estimated in the near-field region, by maximizing the closed-form likelihood function of the wavenumber-domain spectrum conditioned on the scatterers' geometric parameters. Simulation results are provided to demonstrate the robustness of the proposed scheme against both the distance and angles of arrival.
title Wavenumber-Domain Near-Field Channel Estimation: Beyond the Fresnel Bound
topic Signal Processing
Information Theory
url https://arxiv.org/abs/2409.10123