论文标题
双IIRS辅助多用户MIMO的上行链路通道估计
Uplink Channel Estimation for Double-IRS Assisted Multi-User MIMO
论文作者
论文摘要
为了实现在传统的单人IRS系统上的双智能反射表面（IRS）辅助系统中更有前途的被动横梁成型增长，通道估计实际上是必不可少的，而且是一个更具挑战性的问题，不仅存在单个单一的链接，而且还存在双重反转链接。在本文中，我们为双IR辅助上行链路多输入多输出（MIMO）通信系统提出了一种新的高效通道估计方案，以解决其单次和双重反射链接的级联通道状态信息（CSI）。首先，对于单用户案例，通过利用其级联河道系数是较低单维通道的级别级别的版本，在多训练开销中有效地估计了高尺寸的双重反射通道（BS），其训练开销低下。然后，提出的通道估计方案将扩展到多用户案例，在给定任意用户的级联信道估计的情况下，如单用户案例，其他用户的级联通道是其缩放版本的，因此可以通过减少的训练开头来估计培训。与基准方案相比，仿真结果验证了所提出的通道估计方案的有效性。
To achieve the more promising passive beamforming gains in the double-intelligent reflecting surface (IRS) assisted system over the conventional single-IRS system, channel estimation is practically indispensable but also a more challenging problem to tackle, due to the presence of not only the single- but also double-reflection links that are intricately coupled. In this paper, we propose a new and efficient channel estimation scheme for the double-IRS assisted uplink multiple-input multiple-output (MIMO) communication system to resolve the cascaded channel state information (CSI) of both its single- and double-reflection links. First, for the single-user case, the higher-dimensional double-reflection channel is efficiently estimated at the multi-antenna base station (BS) with low training overhead by exploiting the fact that its cascaded channel coefficients are scaled versions of those of a lower-dimensional single-reflection channel. Then, the proposed channel estimation scheme is extended to the multi-user case, where given an arbitrary user's cascaded channel estimated as in the single-user case, the other users' cascaded channels are scaled versions of it and thus can be estimated with reduced training overhead. Simulation results verify the effectiveness of the proposed channel estimation scheme as compared to the benchmark scheme.
