Some New Research Trends in Wirelessly Powered Communications

TL;DR

This paper reviews emerging research trends in wirelessly powered communications (WPC), highlighting practical innovations like backscatter antennas and waveform design, as well as theoretical limits involving super-directivity and large-scale arrays.

Contribution

It introduces new practical techniques and theoretical insights that address key challenges and open problems in advancing WPC from theory to real-world applications.

Findings

Backscatter antennas enable low-complexity passive device support

Spiky waveforms improve power transfer efficiency

Large-scale distributed antenna arrays can enhance fundamental limits

Abstract

The vision of seamlessly integrating information transfer (IT) and microwave based power transfer (PT) in the same system has led to the emergence of a new research area, called wirelessly power communications (WPC). Extensive research has been conducted on developing WPC theory and techniques, building on the extremely rich wireless communications litera- ture covering diversified topics such as transmissions, resource allocations, medium access control and network protocols and architectures. Despite these research efforts, transforming WPC from theory to practice still faces many unsolved prob- lems concerning issues such as mobile complexity, power transfer efficiency, and safety. Furthermore, the fundamental limits of WPC remain largely unknown. Recent attempts to address these open issues has resulted in the emergence of numerous new research trends in the WPC area. A few promising trends are introduced in this article. From the practical perspective, the use of backscatter antennas can support WPC for low-complexity passive devices, the design of spiky waveforms can improve the PT efficiency, and analog spatial decoupling is proposed for solving the PT-IT near-far problem in WPC. From the theoretic perspective, the fundamental limits of WPC can be quantified by leveraging recent results on super-directivity and the limit can be improved by the deployment of large-scale distributed antenna arrays. Specific research problems along these trends are discussed, whose solutions can lead to significant advancements in WPC.