Unmanned aerial vehicle (UAV)-enabled wireless power transfer (WPT) has recently emerged as a promising technique to provide sustainable energy supply for widely distributed low-power ground devices (GDs) in large-scale wireless networks. Compared with the energy transmitters (ETs) in conventional WPT systems which are deployed at fixed locations, UAV-mounted aerial ETs can fly flexibly in the three-dimensional (3D) space to charge nearby GDs more efficiently. This paper provides a tutorial overview on UAV-enabled WPT and its appealing applications, in particular focusing on how to exploit UAVs' controllable mobility via their 3D trajectory design to maximize the amounts of energy transferred to all GDs in a wireless network with fairness. First, we consider the single-UAV-enabled WPT scenario with one UAV wirelessly charging multiple GDs at known locations. To solve the energy maximization problem in this case, we present a general trajectory design framework consisting of three innovative approaches to optimize the UAV trajectory, which are multi-location hovering, successive-hover-and-fly, and time-quantization-based optimization, respectively. Next, we consider the multi-UAV-enabled WPT scenario where multiple UAVs cooperatively charge many GDs in a large area. Building upon the single-UAV trajectory design, we propose two efficient schemes to jointly optimize multiple UAVs' trajectories, based on the principles of UAV swarming and GD clustering, respectively. Furthermore, we consider two important extensions of UAV-enabled WPT, namely UAV-enabled wireless powered communication networks (WPCN) and UAV-enabled wireless powered mobile edge computing (MEC).
A Comprehensive Overview on 5G-and-Beyond Networks with UAVs: From Communications to Sensing and Intelligence
University of Macau（澳门大学）；Future Network of Intelligence Institute（未来网络智能研究院）；The Chinese University of Hong Kong (Shenzhen)（香港中文大学（深圳））；Southeast University（东南大学）；Purple Mountain Laboratories（紫金山实验室）；University of New South Wales（新南威尔士大学）；University of Texas at Dallas（德克萨斯大学达拉斯分校）；Friedrich-Alexander-University Erlangen-Nurnberg（弗里德里希-亚历山大-埃尔朗根-纽伦堡大学）；University of California, Irvine（加州大学欧文分校）
Artificial Neural Networks-Based Machine Learning for Wireless Networks: A Tutorial
Beijing University of Posts and Telecommunications（北京邮电大学）；The Chinese University of Hong Kong, Shenzhen（香港中文大学（深圳））；Princeton University（普林斯顿大学）；The University of Edinburgh（爱丁堡大学）；Virginia Tech（弗吉尼亚理工大学）；Huawei France R & D（华为法国研发中心）
