Wireless information and energy transfer (WIET) represents an emerging paradigm that employs controllable transmission of radio frequency signals for the dual purpose of data communication and wireless charging. As such, WIET is widely regarded as an enabler of envisioned sixth-generation (6G) use cases that rely on energy-sustainable Internet-of-Things (IoT) networks, such as smart cities and smart grids. Meeting the quality-of-service demands of WIET, in terms of both data transfer and power delivery, requires effective codesign of the information and energy signals. In this article, we present the main principles and design aspects of WIET, focusing on its integration in 6G networks. First, we discuss how conventional communication notions, such as resource allocation and waveform design, need to be revisited in the context of WIET. Next, we consider various candidate 6G technologies that can boost WIET efficiency, namely, holographic multiple-input multiple-output, near-field beamforming, terahertz communication, intelligent reflecting surfaces (IRSs), and reconfigurable (fluid) antenna arrays. We introduce respective WIET design methods, analyze the promising performance gains of these WIET systems, and discuss challenges, open issues, and future research directions. Finally, a near-field energy beamforming scheme and a power-based IRS beamforming algorithm are experimentally validated using a wireless energy transfer testbed. The vision of WIET in communication systems has been gaining momentum in recent years, with constant progress with respect to theoretical and also practical aspects. The comprehensive overview of the state of the art of WIET presented in this article highlights the potential of WIET systems and their overall benefits in 6G networks.

中文翻译：

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6G 通信时代的无线信息和能量传输


无线信息和能量传输 （WIET） 代表了一种新兴的范式，它采用射频信号的可控传输来实现数据通信和无线充电的双重目的。因此，WIET 被广泛认为是设想的第六代 （6G） 用例的推动者，这些用例依赖于能源可持续的物联网 （IoT） 网络，例如智能城市和智能电网。满足 WIET 在数据传输和电力传输方面的服务质量要求，需要信息和能源信号的有效协同设计。在本文中，我们介绍了 WIET 的主要原则和设计方面，重点介绍了它在 6G 网络中的集成。首先，我们讨论了如何在 WIET 的背景下重新审视传统的通信概念，例如资源分配和波形设计。接下来，我们考虑了可以提高 WIET 效率的各种候选 6G 技术，即全息多输入多输出、近场波束成形、太赫兹通信、智能反射表面 （IRS） 和可重构（流体）天线阵列。我们介绍了各自的 WIET 设计方法，分析了这些 WIET 系统有前景的性能增益，并讨论了挑战、开放问题和未来的研究方向。最后，使用无线能量传输测试台对近场能量波束形成方案和基于功率的 IRS 波束形成算法进行了实验验证。近年来，WIET 在通信系统方面的愿景势头强劲，在理论和实践方面不断进步。本文全面概述了 WIET 的最新技术水平，重点介绍了 WIET 系统的潜力及其在 6G 网络中的整体优势。