STAR-RISs: Simultaneous Transmitting and Reflecting Reconfigurable Intelligent Surfaces
TLDR
Compared with the conventional reflecting-only RISs, the coverage of STAR-RISs is extended to 360 degrees via simultaneous transmission and reflection and channel models are proposed for the near-field and the far-field scenarios, base on which the diversity gain is analyzed and compared with that of the conventional RISs.Abstract:
In this letter, simultaneous transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) are studied. Compared with the conventional reflecting-only RISs, the coverage of STAR-RISs is extended to 360 degrees via simultaneous transmission and reflection. A general hardware model for STAR-RISs is presented. Then, channel models are proposed for the near-field and the far-field scenarios, based on which the diversity gain of the STAR-RISs is analyzed and compared with that of the conventional RISs. Numerical simulations are provided to verify analytical results and to demonstrate that full diversity order can be achieved on both sides of the STAR-RIS.read more
Citations
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Journal ArticleDOI
Reconfigurable Intelligent Surfaces for Wireless Communications: Overview of Hardware Designs, Channel Models, and Estimation Techniques
Men Jian,George C. Alexandropoulos,Ertugrul Basar,Chongwen Huang,Ruiqi Liu,Yuanwei Liu,Chau Yuen +6 more
TL;DR: An overview and taxonomize the latest advances in RIS hardware architectures as well as the most recent developments in the modeling of RIS unit elements and RIS-empowered wireless signal propagation, which constitute a prerequisite step for the optimized incorporation of RISs in future wireless networks.
Journal ArticleDOI
Coverage Characterization of STAR-RIS Networks: NOMA and OMA
TL;DR: In this paper, a sum coverage range maximization problem is formulated for both NOMA and orthogonal multiple access (OMA), where the resource allocation at the access point and the transmission and reflection coefficients at the STAR-RIS are jointly optimized to satisfy the communication requirements of users.
Journal ArticleDOI
Simultaneous Transmission and Reflection Reconfigurable Intelligent Surface Assisted Secrecy MISO Networks
TL;DR: This work exploits the potential of a novel simultaneous transmission and reflection reconfigurable intelligent surface (STAR-RIS) in improving the security in a multiple-input single-output (MISO) network, where three transmission protocols, namely, energy splitting, mode selection, and time splitting, are studied.
Joint Design for Simultaneously Transmitting and Reflecting (STAR) RIS Assisted NOMA Systems
TL;DR: In this paper , a novel RIS assisted NOMA (STAR-RIS-NOMA) system is proposed to maximize the achievable sum rate by jointly optimizing the decoding order, power allocation coefficients, active beamforming, and transmission and reflection beamforming.
Journal ArticleDOI
Reconfigurable Intelligent Surfaces: Channel Characterization and Modeling
Jie Huang,Chenghai Wang,Yingzhuo Sun,Rui Feng,Jialing Huang,Bolun Guo,Zhimeng Zhong,Tie Jun Cui +7 more
TL;DR: RIS-based channel modeling works are investigated, including large-scale path loss models and small-scale multipath fading models, and future research directions related to RIS-assisted channels are discussed.
References
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Reconfigurable Intelligent Surfaces: Principles and Opportunities
TL;DR: A comprehensive overview of the state-of-the-art on RISs, with focus on their operating principles, performance evaluation, beamforming design and resource management, applications of machine learning to RIS-enhanced wireless networks, as well as the integration of RISs with other emerging technologies.