Near/Far-Field Channel Estimation For Terahertz Systems With ELAAs: A Block-Sparse-Aware Approach

作     者：Wang, Hongwei Fang, Jun Duan, Huiping Li, Hongbin 

作者机构：National Key Laboratory of Wireless Communications University of Electronic Science and Technology of China Chengdu611731 China School of Information and Communications Engineering University of Electronic Science and Technology of China Chengdu611731 China Department of Electrical and Computer Engineering Stevens Institute of Technology HobokenNJ07030 United States 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Channel estimation 

摘      要：Millimeter wave/Terahertz (mmWave/THz) communication with extremely large-scale antenna arrays (ELAAs) offers a promising solution to meet the escalating demand for high data rates in next-generation communications. A large array aperture, along with the ever increasing carrier frequency over the mmWave/THz bands, leads to a large Rayleigh distance. As a result, the traditional planar-wave assumption may not hold valid for mmWave/THz systems featuring ELAAs. In this paper, we consider the problem of hybrid near/far-field channel estimation by taking spherical wave propagation into account. By analyzing the coherence properties of any two near-field steering vectors, we prove that the hybrid near/far-field channel admits a blocksparse representation on a specially designed unitary matrix. Specifically, the percentage of nonzero elements of such a blocksparse representation is in the order of 1/pN, which tends to zero as the number of antennas, N, grows. Such a block-sparse representation allows to convert channel estimation into a blocksparse signal recovery problem. Simulation results are provided to verify our theoretical results and illustrate the performance of the proposed channel estimation approach in comparison with existing state-of-the-art methods. Copyright © 2024, The Authors. All rights reserved.