论文标题
无线通信的非局部可重新配置智能表面：建模和物理层方面
Nonlocal Reconfigurable Intelligent Surfaces for Wireless Communication: Modeling and Physical Layer Aspects
论文作者
论文摘要
用于无线通信的常规可重构智能表面（RIS）在表面上具有局部依赖位置（相梯度）散射响应。我们考虑更一般的RIS结构，称为非局部（或重定向）RI，它们能够根据入射角有选择地操纵撞击波。重定向RI具有非局部波前选择性散射行为，可以使用多层阵列（例如金属）实现。我们证明，这种更复杂的表面类型具有多个优点，例如：通过基于CoodeBook的可重构性，解耦的波浪操作以及通过多功能操作在多源场景中较高的效率。此外，重定向RIS体系结构极大地使波浪传播在高频下的定向性质，并且可以最有效地支持集成的Fronthaul和访问（IFA）网络。我们还讨论了可伸缩性和紧凑性问题，并提出了有效的非本地RIS体系结构，例如基于镜头的RIS和镜像支持的相掩膜结构，这些结构不需要额外的控制复杂性和开销，同时仍然提供比常规本地RIS更好的性能。
Conventional Reconfigurable intelligent surfaces (RIS) for wireless communications have a local position-dependent (phase-gradient) scattering response on the surface. We consider more general RIS structures, called nonlocal (or redirective) RIS, that are capable of selectively manipulate the impinging waves depending on the incident angle. Redirective RIS have nonlocal wavefront-selective scattering behavior and can be implemented using multilayer arrays such as metalenses. We demonstrate that this more sophisticated type of surfaces has several advantages such as: lower overhead through coodebook-based reconfigurability, decoupled wave manipulations, and higher efficiency in multiuser scenarios via multifunctional operation. Additionally, redirective RIS architectures greatly benefit form the directional nature of wave propagation at high frequencies and can support integrated fronthaul and access (IFA) networks most efficiently. We also discuss the scalability and compactness issues and propose efficient nonlocal RIS architectures such as fractionated lens-based RIS and mirror-backed phase-masks structures that do not require additional control complexity and overhead while still offering better performance than conventional local RIS.
