Status and Prospect of Intelligent Reflecting Surfaces for Green Communication System

With the further evolution of communication technology, the era of the Internet of Everything is becoming a visible future. In Sixth-Generation (6G) communication networks, in addition to higher communication rates, lower latency, and more intelligent network management, larger system capacity, wider coverage, lower energy consumption, and lower costs are also required. The combination of Reconfigurable Intelligent Surface (RIS) technology and Simultaneous Wireless Information and Power Transfer (SWIPT) technology can not only ensure the communication quality, but also provide reliable technical support for 6G communication in terms of low power consumption, low cost and wide coverage. This paper presents an overview of the development process and existing problems of RIS-assisted SWIPT systems, aiming to discuss the application potentials and challenges of these systems in 6G communication. Firstly, the new demands in 6G communication are discussed, and by comparing Wireless Power Transfer (WPT) technology and SWIPT technology, the advantages and unresolved issues of SWIPT technology in wireless communication scenarios are elaborated. Then, the characteristics and research status of RIS technology were introduced. The paper points out that RIS assisted SWIPT systems will achieve improvements in spectral and energy efficiency, and analyzes the technical challenges currently present in the system. Finally, the future research directions and application prospects of RIS assisted SWIPT systems are discussed.