{"title":"Robust Energy Efficiency Optimization for Double-RIS-Assisted Wireless-Powered Backscatter Communications","authors":"Yongjun Xu;Yingxiang Bai;Yunjian Jia;Haibo Zhang;Qingqing Wu;Chau Yuen","doi":"10.1109/TCCN.2024.3438354","DOIUrl":null,"url":null,"abstract":"To explore the potential of multiple collaborative reconfigurable intelligent surfaces (RISs) for wireless-powered backscatter communications (WP-BackCom), in this paper, we investigate a robust energy efficiency (EE) optimization problem for a double-RIS-assisted WP-BackCom system, where a power station (PS) transmits wireless energy signals to multiple backscatter devices (BDs) via one RIS during the energy-harvesting phase, and then all BDs use the harvested energy for active transmission via another RIS. The total EE of all BDs with bounded channel uncertainties is maximized by jointly optimizing the beamforming vectors of the PS and RISs, transmission power, reflection coefficients, and time allocation factors. To solve the challenging problem, an iterative robust resource allocation algorithm is designed by employing the alteration optimization approach, the worst-case approach, the penalty function method, and the Gaussian randomization method. Simulation results verify that the proposed algorithm has strong robustness and higher EE.","PeriodicalId":13069,"journal":{"name":"IEEE Transactions on Cognitive Communications and Networking","volume":"10 5","pages":"1718-1729"},"PeriodicalIF":7.4000,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Transactions on Cognitive Communications and Networking","FirstCategoryId":"94","ListUrlMain":"https://ieeexplore.ieee.org/document/10623417/","RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"TELECOMMUNICATIONS","Score":null,"Total":0}
引用次数: 0
Abstract
To explore the potential of multiple collaborative reconfigurable intelligent surfaces (RISs) for wireless-powered backscatter communications (WP-BackCom), in this paper, we investigate a robust energy efficiency (EE) optimization problem for a double-RIS-assisted WP-BackCom system, where a power station (PS) transmits wireless energy signals to multiple backscatter devices (BDs) via one RIS during the energy-harvesting phase, and then all BDs use the harvested energy for active transmission via another RIS. The total EE of all BDs with bounded channel uncertainties is maximized by jointly optimizing the beamforming vectors of the PS and RISs, transmission power, reflection coefficients, and time allocation factors. To solve the challenging problem, an iterative robust resource allocation algorithm is designed by employing the alteration optimization approach, the worst-case approach, the penalty function method, and the Gaussian randomization method. Simulation results verify that the proposed algorithm has strong robustness and higher EE.
期刊介绍:
The IEEE Transactions on Cognitive Communications and Networking (TCCN) aims to publish high-quality manuscripts that push the boundaries of cognitive communications and networking research. Cognitive, in this context, refers to the application of perception, learning, reasoning, memory, and adaptive approaches in communication system design. The transactions welcome submissions that explore various aspects of cognitive communications and networks, focusing on innovative and holistic approaches to complex system design. Key topics covered include architecture, protocols, cross-layer design, and cognition cycle design for cognitive networks. Additionally, research on machine learning, artificial intelligence, end-to-end and distributed intelligence, software-defined networking, cognitive radios, spectrum sharing, and security and privacy issues in cognitive networks are of interest. The publication also encourages papers addressing novel services and applications enabled by these cognitive concepts.