大规模STAR-RIS辅助的近场ISAC传输方法  

Large-Scale STAR-RIS Assisted Near-Field ISAC Transmission Method

作　　者：王小明[1] 李佳琪 刘婷[2] 蒋锐[1] 徐友云 WANG Xiaoming;LI Jiaqi;LIU Ting;JIANG Rui;XU Youyun(School of Communication and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China;School of Artificial Intelligence(School of Future Technology),Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京邮电大学通信与信息工程学院,南京210003 [2]南京信息工程大学人工智能学院(未来技术学院),南京210044

出　　处：《电子与信息学报》2025年第1期147-155,共9页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(62101274,62371246)。

摘　　要：同时透射和反射可重构智能表面(STAR-RIS)能够创建全空间智能无线电环境,有效提高无线通信系统性能,具有广阔的研究潜力。因此,该文提出一种大规模STAR-RIS辅助的近场通感一体化(ISAC)方法,并对感知目标3维参数估计的克拉美罗界(CRB)进行优化。首先,搭建近场系统模型,分别推导基站、STAR-RIS、通信用户、感知目标与传感器之间的导向矢量。其次,通过设计基站发射波束成形矩阵、发射信号协方差矩阵和STAR-RIS透射反射系数,实现感知性能最优化。再次,针对非凸优化问题利用半正定松弛方法进行求解。仿真结果表明了所提出ISAC方案的有效性,以及近场额外距离自由度所带来的定位性能优势。Objective The growing demand for advanced service applications and the stringent performance requirements envisioned in future 6G networks have driven the development of Integrated Sensing and Communication(ISAC).By combining sensing and communication capabilities,ISAC enhances spectral efficiency and has attracted significant research attention.However,real-world signal propagation environments are often suboptimal,making it difficult to achieve optimal transmission and sensing performance under harsh or dynamic conditions.To address this,Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surfaces(STAR-RIS)enable a full-space programmable wireless environment,offering an effective solution to enhance wireless system capabilities.In large-scale 6G industrial scenarios,STAR-RIS panels could be deployed on rooftops and walls for comprehensive coverage.As the number of reflecting elements increases,near-field effects become significant,rendering the conventional far-field assumption invalid.This paper explores the application of large-scale STAR-RIS in near-field ISAC systems,highlighting the role of near-field effects in enhancing sensing and communication performance.It highlights the importance of incorporating near-field phenomena into system design to exploit the additional degrees of freedom provided by large-scale STAR-RIS for improved localization accuracy and communication quality.Methods First,near-field ISAC system is formulated,where a large-scale STAR-RIS assists both sensing and communication processes.The theoretical framework of near-field steering vectors is applied to derive the steering vectors for each link,including those from the Base Station(BS)to the STAR-RIS,from the STAR-RIS to communication users,from the STAR-RIS to sensing targets,and from sensing targets to sensors.Based on these vectors,a system model is constructed to characterize the relationships among transmitted signals,signals reflected or transmitted via the STAR-RIS,and received signals for both communication

关 键 词：可重构智能表面 通感一体化 近场通信 克拉美罗界 

分 类 号：TN929.5[电子电信—通信与信息系统]