Pub Date : 2024-11-20DOI: 10.1109/LCOMM.2024.3502716
Tao Luo;Hancheng Lu;Baolin Chong
User-centric networking is expected to be a promising technology to implement ultra-reliable and low-latency communication (URLLC). However, the densely deployed access points (APs) in a user-centric network (UCN) will involve significant hardware costs and energy consumption. To address this issue, we propose a reconfigurable intelligent surface (RIS)-aided UCN for URLLC. Then, a joint optimization problem with consideration of active beamforming at APs and passive beamforming at RISs is formulated to achieve optimal energy efficiency (EE). Since the problem is intractable and non-convex, we develop an alternating optimization algorithm based on the inner approximation framework to solve it efficiently. Numerical results verify that the proposed algorithm outperforms baseline algorithms regarding EE. Particularly, with the proposed algorithm, our RIS-aided UCN achieves up to 147% performance gains in terms of EE compared to traditional UCN.
{"title":"Energy Efficiency Optimization for URLLC in RIS-Aided User-Centric Networks","authors":"Tao Luo;Hancheng Lu;Baolin Chong","doi":"10.1109/LCOMM.2024.3502716","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3502716","url":null,"abstract":"User-centric networking is expected to be a promising technology to implement ultra-reliable and low-latency communication (URLLC). However, the densely deployed access points (APs) in a user-centric network (UCN) will involve significant hardware costs and energy consumption. To address this issue, we propose a reconfigurable intelligent surface (RIS)-aided UCN for URLLC. Then, a joint optimization problem with consideration of active beamforming at APs and passive beamforming at RISs is formulated to achieve optimal energy efficiency (EE). Since the problem is intractable and non-convex, we develop an alternating optimization algorithm based on the inner approximation framework to solve it efficiently. Numerical results verify that the proposed algorithm outperforms baseline algorithms regarding EE. Particularly, with the proposed algorithm, our RIS-aided UCN achieves up to 147% performance gains in terms of EE compared to traditional UCN.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"110-114"},"PeriodicalIF":3.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142940867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1109/LCOMM.2024.3503754
Qin Zhang;Han Wu;Hai Li;Zhengyu Song;Shujuan Hou
In this letter, we investigate a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided integrated sensing and communication (ISAC) system. Our object is to maximize the energy efficiency (EE) of the ISAC system by jointly optimizing the beamforming at the base station (BS), the transmitting/reflecting coefficient matrices of the STAR-RIS, as well as the deployment location of the STAR-RIS. Since the formulated problem is non-convex, we propose an alternative optimization scheme by decomposing the original problem into three sub-problems, where the sub-problems are solved based on semidefinite relaxation (SDR) and fractional programming. Simulation results demonstrate that the STAR-RIS aided ISAC system achieves a higher EE than conventional RIS scheme, and the location optimization for STAR-RIS can significantly improve the system EE. Furthermore, the EE declines rapidly when the radar beampattern gain threshold increases to a larger value.
{"title":"Joint Location and Beamforming Design for Energy Efficient STAR-RIS-Aided ISAC Systems","authors":"Qin Zhang;Han Wu;Hai Li;Zhengyu Song;Shujuan Hou","doi":"10.1109/LCOMM.2024.3503754","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3503754","url":null,"abstract":"In this letter, we investigate a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided integrated sensing and communication (ISAC) system. Our object is to maximize the energy efficiency (EE) of the ISAC system by jointly optimizing the beamforming at the base station (BS), the transmitting/reflecting coefficient matrices of the STAR-RIS, as well as the deployment location of the STAR-RIS. Since the formulated problem is non-convex, we propose an alternative optimization scheme by decomposing the original problem into three sub-problems, where the sub-problems are solved based on semidefinite relaxation (SDR) and fractional programming. Simulation results demonstrate that the STAR-RIS aided ISAC system achieves a higher EE than conventional RIS scheme, and the location optimization for STAR-RIS can significantly improve the system EE. Furthermore, the EE declines rapidly when the radar beampattern gain threshold increases to a larger value.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"140-144"},"PeriodicalIF":3.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this letter, we propose a novel communication system for multiple Non-Orthogonal Multiple Access (NOMA)-based end-users, leveraging a mixed THz-RF wireless communication approach. The THz link serves as the backhaul communication link and is characterized by an $alpha -mu $