Channel Estimation for RIS-Aided Multi-User mmWave Systems with Uniform Planar Arrays

作     者：Peng, Zhendong Zhou, Gui Pan, Cunhua Ren, Hong Lee Swindlehurst, A. Popovski, Petar Wu, Gang 

作者机构：The University of Electronic Science and Technology China  Erlangen91054 Germany The National Mobile Communications Research Laboratory Southeast University Nanjing210096 China The Center for Pervasive Communications and Computing University of California IrvineCA92697 United States The Department of Electronic Systems Aalborg University Aalborg9220 Denmark The National Key Laboratory of Science and Technology on Communication University of Electronic Science and Technology of China Chengdu611731 China 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2022年

核心收录：

主　　题：Channel estimation 

摘      要：In this paper, we adopt a three-stage based uplink channel estimation protocol with reduced pilot overhead for an reconfigurable intelligent surface (RIS)-aided multi-user (MU) millimeter wave (mmWave) communication system, in which both the base station (BS) and the RIS are equipped with a uniform planar array (UPA). Specifically, in Stage I, the channel state information (CSI) of a typical user is estimated. To address the power leakage issue for the common angles-of-arrival (AoAs) estimation in this stage, we develop a low-complexity one-dimensional search method. In Stage II, a re-parameterized common BS-RIS channel is constructed with the estimated information from Stage I to estimate other users CSI. In Stage III, only the rapidly varying channel gains need to re-estimated. Furthermore, the proposed method can be extended to multi-antenna UPA-type users, by decomposing the estimation of a multi-antenna channel with J scatterers into estimating J single-scatterer channels for a virtual single-antenna user. An orthogonal matching pursuit (OMP)-based method is proposed to estimate the angles-of-departure (AoDs) at the users. Simulation results demonstrate that the proposed algorithm significantly achieves high channel estimation accuracy, which approaches the genie-aided upper bound in the high signal-to-noise ratio (SNR) regime. Copyright © 2022, The Authors. All rights reserved.