论文标题
除了对角线可重构智能表面：从传输和反射模式到单，组和完全连接的体系结构
Beyond Diagonal Reconfigurable Intelligent Surfaces: From Transmitting and Reflecting Modes to Single-, Group-, and Fully-Connected Architectures
论文作者
论文摘要
可重构智能表面（RISS）被设想为未来无线通信的有前途的技术。通过各种硬件实现，RIS可以在不同的模式（反射/传播/混合动力车）下工作，或具有不同的架构（单/组/完全连接）。但是，大多数现有的研究都集中在单连接的反射性RIS上，以对角相移矩阵为特征，而缺乏对RISS统一不同模式/体系结构的全面研究。在本文中，我们通过分析和提出了一个通用的RIS辅助通信模型来解决此问题。具体而言，我们建立了一个不限于对角线相移矩阵的RIS模型，这是一个新的分支，称为对角线RIS（BD-RIS），统一模式和体系结构。通过提出的模型，我们开发了有效的算法来共同设计传输预编码器和BDRIS矩阵，以最大程度地提高RIS AIDED系统的总和率。我们还提供了仿真结果，以将BD-Riss的性能与不同的模式/体系结构进行比较。仿真结果表明，在同一模式下，与单连接的RI相比，在完全和组相互连接的RIS可以有效地提高总和率的性能，而Hybrid RIS的表现优于具有相同架构的反射/透射性RI。
Reconfigurable intelligent surfaces (RISs) are envisioned as a promising technology for future wireless communications. With various hardware realizations, RISs can work under different modes (reflective/transmissive/hybrid) or have different architectures (single/group/fully-connected). However, most existing research focused on single-connected reflective RISs, mathematically characterized by diagonal phase shift matrices, while there is a lack of a comprehensive study for RISs unifying different modes/architectures. In this paper, we solve this issue by analyzing and proposing a general RIS-aided communication model. Specifically, we establish an RIS model not limited to diagonal phase shift matrices, a novel branch referred to as beyond diagonal RIS (BD-RIS), unifying modes and architectures. With the proposed model, we develop efficient algorithms to jointly design transmit precoder and BDRIS matrix to maximize the sum-rate for RIS-aided systems. We also provide simulation results to compare the performance of BD-RISs with different modes/architectures. Simulation results show that under the same mode, fully- and group-connected RIS can effectively increase the sum-rate performance compared with single-connected RIS, and that hybrid RIS outperforms reflective/transmissive RIS with the same architecture.
