[论文解读] Smart Radio Environments Empowered by AI Reconfigurable Meta-Surfaces: An Idea Whose Time Has Come

Marco Di Renzo, Mérouane Debbah+12 more|arXiv (Cornell University)|Mar 21, 2019

Advanced Wireless Communication Technologies参考文献 108被引用 50

一句话总结

本文主张通过 AI 驱动的可重构超表面实现的智能无线环境，这些超表面能够感知、报告并重塑无线传播，以提升通信并在不产生新射频信号的情况下实现节能感知与计算。

ABSTRACT

Future wireless networks are expected to constitute a distributed intelligent wireless communications, sensing, and computing platform, which will have the challenging requirement of interconnecting the physical and digital worlds in a seamless and sustainable manner. Currently, two main factors prevent wireless network operators from building such networks: 1) the lack of control of the wireless environment, whose impact on the radio waves cannot be customized, and 2) the current operation of wireless radios, which consume a lot of power because new signals are generated whenever data has to be transmitted. In this paper, we challenge the usual "more data needs more power and emission of radio waves" status quo, and motivate that future wireless networks necessitate a smart radio environment: A transformative wireless concept, where the environmental objects are coated with artificial thin films of electromagnetic and reconfigurable material (that are referred to as intelligent reconfigurable meta-surfaces), which are capable of sensing the environment and of applying customized transformations to the radio waves. Smart radio environments have the potential to provide future wireless networks with uninterrupted wireless connectivity, and with the capability of transmitting data without generating new signals but recycling existing radio waves. This paper overviews the current research efforts on smart radio environments, the enabling technologies to realize them in practice, the need of new communication-theoretic models for their analysis and design, and the long-term and open research issues to be solved towards their massive deployment. In a nutshell, this paper is focused on discussing how the availability of intelligent reconfigurable meta-surfaces will allow wireless network operators to redesign common and well-known network communication paradigms.

研究动机与目标

• 将智能无线环境概念作为解决失控的无线传播和高功耗的方案进行动机说明。
• 介绍可重构超表面作为实现环境中可控波变换的使能技术。
• 讨论超表面的感知、报告与计算能力及其在网络控制中的整合。
• 提出一种新的通信理论模型，用于分析和优化表面启用环境的大规模部署。
• 明确至大规模部署的开放研究问题和实际挑战。

提出的方法

• 描述超表面和可重构界面的物理原理（局部相位位移、反射/折射的一般化定律）。
• 提出一种系统架构，由网络控制器通过感知数据和反馈来配置环境表面。
• 说明基于 meta-surface 的调制用于传感数据传输，无需额外辐射。
• 对比智能无线环境与传统网络，并讨论能源中性运行和回传链路考虑。
• 主张一种新的理论框架，将环境视为一个主动、可编程的要素，而非被动障碍。

实验结果

研究问题

• RQ1 如何在大规模无线网络中集成和协调可重构超表面？
• RQ2 采用可重构表面的智能无线环境的网络的最终性能极限是什么？
• RQ3 为实现环境的最佳配置需要多少感知和反馈数据？
• RQ4 需要哪些实际算法和模型来实时编排大量的元表面？
• RQ5 元表面对未来网络的能效、干扰和安全性有何影响？

主要发现

• 可重构的 meta-surfaces 可以将环境对象转换为可编程反射器，从而改善覆盖范围和链路可靠性。
• 基于 meta-surface 的调制通过将数据编码到反射波中，使微小、由电池供电的传感器能够进行通信，潜在地消除新传输的需要。
• 智能无线环境提供一种节能、可扩展的方式来循环利用现有的无线电波，而不是生成新的信号。
• 提出了一种在通信理论模型上的转变：从端点为中心的优化转向环境感知的联合优化。
• 本文指出关键的开放性问题，包括数据开销、感知需求，以及在大规模网络中对多个表面的编排。