A realistic performance assessment of any wireless technology requires the
use of a channel model that reflects its main characteristics. The independent
and identically distributed Rayleigh fading channel model has been (and still
is) the basis of most theoretical research on multiple antenna technologies in
scattering environments. This letter shows that such a model is not physically
appearing when using a reconfigurable intelligent surface (RIS) with
rectangular geometry and provides an alternative physically feasible Rayleigh
fading model that can be used as a baseline when evaluating RIS-aided
communications. The model is used to revisit the basic RIS properties, e.g.,
the rank of spatial correlation matrices and channel hardening.

本文评估了使用可重构智能表面（RIS）时，独立同分布的瑞利衰落信道模型不再是基于散射环境中的多天线技术的理论研究的基础，并提出了一种可用于评估 RIS 辅助通信的可行的瑞利衰落模型。该模型用于重新审视 RIS 的基本属性，例如，空间相关矩阵的秩和信道硬化。