标题： 无线能量传输的波形设计 显示英文标题

标题： Waveform Design for Wireless Power Transfer

摘要： 远场无线功率传输（WPT）近年来引起了广泛关注。尽管取得了快速进展，但过去十年里研究社区的重点仍然主要集中在改进能量收集器（即所谓的整流天线）的设计上，而忽略了发射机设计的影响。本文研究了发射波形的设计以增强整流天线的直流输出功率。我们推导出整流天线非线性的一个可处理模型，并将其与文献中常用的线性模型进行了比较。然后，我们利用这些模型来设计适应信道状态信息（CSI）的新颖多正弦波形。有趣的是，虽然线性模型倾向于窄带传输并将所有功率分配到单一频率，而非线性模型则倾向于在多个频率上分配功率。通过现实的仿真表明，基于非线性模型设计的波形在收集的直流功率方面比基于线性模型设计的波形以及非自适应波形提供了显著增益。我们还从理论上计算了各种波形下收集的能量随正弦波数量和发送天线数量变化的理论标度规律。这些标度规律强调了在WPT中发射机处了解CSI的重要性，以及基于非线性整流天线模型的WPT设计优于线性模型。结果还激发了对一种有前景架构的研究，该架构依赖于大规模多正弦多天线波形用于WPT。最后，结果强调了在涉及无线功率的任何系统设计中建模并考虑整流天线非线性的重要性。 显示英文摘要

摘要： Far-field Wireless Power Transfer (WPT) has attracted significant attention in recent years. Despite the rapid progress, the emphasis of the research community in the last decade has remained largely concentrated on improving the design of energy harvester (so-called rectenna) and has left aside the effect of transmitter design. In this paper, we study the design of transmit waveform so as to enhance the DC power at the output of the rectenna. We derive a tractable model of the non-linearity of the rectenna and compare with a linear model conventionally used in the literature. We then use those models to design novel multisine waveforms that are adaptive to the channel state information (CSI). Interestingly, while the linear model favours narrowband transmission with all the power allocated to a single frequency, the non-linear model favours a power allocation over multiple frequencies. Through realistic simulations, waveforms designed based on the non-linear model are shown to provide significant gains (in terms of harvested DC power) over those designed based on the linear model and over non-adaptive waveforms. We also compute analytically the theoretical scaling laws of the harvested energy for various waveforms as a function of the number of sinewaves and transmit antennas. Those scaling laws highlight the benefits of CSI knowledge at the transmitter in WPT and of a WPT design based on a non-linear rectenna model over a linear model. Results also motivate the study of a promising architecture relying on large-scale multisine multi-antenna waveforms for WPT. As a final note, results stress the importance of modeling and accounting for the non-linearity of the rectenna in any system design involving wireless power.