论文标题
锚固辅助智能反映多源通信的表面渠道估计
Anchor-Assisted Intelligent Reflecting Surface Channel Estimation for Multiuser Communications
论文作者
论文摘要
由于智能反射表面（IRS）的被动性质，通道估计是IRS辅助无线网络的基本挑战。特别是，随着反映IRS服务用户的IRS的数量和/或IRS服务用户的数量增加，渠道培训间接开销变得过高。为了应对这一挑战，我们在本文中提出了一种新的锚固辅助两相通道估计方案，其中将两个锚节点（即A1和A2）部署在IRS附近，以帮助基站（BS）获取层叠的BS-IRS-IRS-user通道。具体而言，在第一阶段，通过估算BS-IRS-A1/A2通道和A1-IRS-A2通道，可以获得BS-IRS链接的部分通道状态信息（CSI），即BS-IRS链接的元素频道增益正方形。然后，在第二阶段，通过利用对所有用户共有的BS-IRS通道的部分知识，可以有效地估计单个级联的BS-IRS-用户通道。仿真结果表明，与传统方案相比，所提出的锚固辅助通道估计方案能够实现可比的于点误差（MSE）性能，但大大减少了通道训练时间。
Due to the passive nature of Intelligent Reflecting Surface (IRS), channel estimation is a fundamental challenge in IRS-aided wireless networks. Particularly, as the number of IRS reflecting elements and/or that of IRS-served users increase, the channel training overhead becomes excessively high. To tackle this challenge, we propose in this paper a new anchor-assisted two-phase channel estimation scheme, where two anchor nodes, namely A1 and A2, are deployed near the IRS for helping the base station (BS) to acquire the cascaded BS-IRS-user channels. Specifically, in the first phase, the partial channel state information (CSI), i.e., the element-wise channel gain square, of the BS-IRS link is obtained by estimating the BS-IRS-A1/A2 channels and the A1-IRS-A2 channel, separately. Then, in the second phase, by leveraging such partial knowledge of the BS-IRS channel that is common to all users, the individual cascaded BS-IRS-user channels are efficiently estimated. Simulation results demonstrate that the proposed anchor-assisted channel estimation scheme is able to achieve comparable mean-squared error (MSE) performance as compared to the conventional scheme, but with significantly reduced channel training time.
