论文标题
RIS辅助多用户MMWave系统的频道估计具有均匀的平面阵列
Channel Estimation for RIS-Aided Multi-User mmWave Systems with Uniform Planar Arrays
论文作者
论文摘要
在本文中，我们采用了一个基于三阶段的上行链路通道估计协议，其飞行员开销降低了可重构智能表面（RIS）辅助的多用户（MU）毫米波（MMWave）通信系统，其中基地站（BS）和RIS都配备了均匀的平面阵列（UPA）。具体而言，在第一阶段，估计了典型用户的通道状态信息（CSI）。为了解决此阶段的常见角度（AOAS）估计的功率泄漏问题，我们开发了一种低复杂性的一维搜索方法。在第二阶段，重新参数化的常见BS-RIS通道是通过I阶段I估算其他用户CSI的估计信息构建的。在第三阶段，只有迅速变化的通道收益才需要重新估计。此外，通过分解具有$ j $ scatterers的多端nane频道的估算来估算虚拟单散射器通道的估算，可以将所提出的方法扩展到多Antenna UPA型用户。提出了一种基于正交的匹配追踪（OMP）方法，以估算用户的开发角度（AOD）。仿真结果表明，所提出的算法显着达到了高通道估计的精度，该算法接近了高SNR状态中的Genie辅助上限。
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 SNR regime.
