Title: Generalised Impedance Model of Wireless Links Assisted by Reconfigurable Intelligent Surfaces Show Chinese title

Title: 基于可重构智能表面辅助的无线链路广义阻抗模型

Abstract: We devise an end-to-end communication channel model that describes the performance of RIS-assisted MIMO wireless links. The model borrows the impedance (interaction) matrix formalism from the Method of Moments and provides a physics-based communication model. In configurations where the transmit and receive antenna arrays are distant from the RIS beyond a wavelength, a reduced model provides accurate results for arbitrary RIS unit cell geometry. Importantly, the simplified model configures as a cascaded channel transfer matrix whose mathematical structure is compliant with widely accepted, but less accurate, system level RIS models. A numerical validation of the communication model is presented for the design of binary RIS structures with scatterers of canonical geometry. Attained results are consistent with path-loss models: For obstructed line-of-sight between transmitter and receiver, the channel capacity of the (optimised) RIS-assisted link scales as $R^{-2}$, with $R$ RIS-receiver distance at fixed transmitter position. Our results shows that the applicability of communication models based on mutual impedance matrices is not restricted to canonical minimum scattering RIS unit cells. Show Chinese abstract

Abstract: 我们设计了一个端到端的通信信道模型，该模型描述了RIS辅助的MIMO无线链路的性能。 该模型借鉴了矩量法中的阻抗（相互作用）矩阵形式，并提供了一个基于物理的通信模型。 在发射和接收天线阵列远离RIS超过波长的配置中，一个简化模型能够为任意RIS单元结构几何提供准确的结果。 重要的是，简化模型配置为级联信道转移矩阵，其数学结构符合广泛接受但准确性较低的系统级RIS模型。 针对具有规范几何散射体的二进制RIS结构的设计，给出了通信模型的数值验证。 获得的结果与路径损耗模型一致：对于发射器和接收器之间的遮挡视距，(优化) RIS辅助链路的信道容量按 $R^{-2}$变化，其中在固定发射器位置时，$R$为RIS接收器距离。 我们的结果表明，基于互阻抗矩阵的通信模型的应用并不局限于规范的最小散射RIS单元结构。