In this paper, we design, prototype, and experiment a closed-loop radiative wireless power transfer (WPT) system with adaptive waveform and beamforming using limited feedback. Spatial and frequency domains are exploited by jointly utilizing multi-sine waveform and multi-antenna beamforming at the transmitter in WPT system to adapt to the multipath fading channel and boost the output dc power. A closed-loop architecture based on a codebook design and a low complexity over-the-air limited feedback using an IEEE 802.15.4 RF interface is proposed. The codebook consists of multiple codewords where each codeword represents particular waveform and beamforming. The transmitter sweeps through the codebook and then the receiver feeds back the index of the optimal codeword, so that the waveform and beamforming can be adapted to the multipath fading channel to maximize the output dc power without requiring explicit channel estimation and the knowledge of accurate Channel State Information. The proposed closed-loop WPT with adaptive waveform and beamforming using limited feedback is prototyped using a Software Defined Radio equipment and measured in a real indoor environment. The measurement results show that the proposed closed-loop WPT with adaptive waveform and beamforming can increase the output dc power by up to 14.7 dB compared with the conventional single-tone and single-antenna WPT system.

翻译：在本文中,我们设计、原型和实验一个使用有限反馈的适应波形和波形成形的闭路散热无线电源传输系统(WPT)系统。空间和频域通过在WPT系统中的发报器上联合使用多线波形和多线天线波形波状和多线天线光束波状,以适应多路流淡化频道,并提升输出 dc 功率。一个基于代码簿设计和低复杂性的超线环无线无线电传输系统(WPT)系统,使用IEEEE 802.15.4 RF接口。代码手册包括多个编码词,其中每个编码代表特定的波形和波形。发送器通过代码簿扫描,然后接收器反馈最佳编码的索引,以便波形波状和波状光束能够适应多路路道,从而在不需要明确频道估计和准确的频道状态信息知识的情况下,最大限度地实现输出 dc。拟议的有适应波状波状和成型的封闭式WPT,使用有限的反馈,将使用软件定义和波形系统进行原样化,通过编码进行扫描,通过编码扫描的比较的无线电波状无线电设备进行扫描测量,以显示实际的平整型无线电波状,在常规环境中测制成。