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Related papers: Multi-Active RIS-Assisted THz Cell-Free Systems: S…

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In this paper, a multiple-input multiple-output (MIMO) wireless system incorporating a reconfigurable intelligent surface (RIS) to efficiently operate at terahertz (THz) frequencies is considered. The transmitter, Alice, employs…

Information Theory · Computer Science 2024-12-30 Sushil Kumar , Soumya P. Dash , Debasish Ghose , George C. Alexandropoulos

In this paper, we explore the integration of low-power, low-cost stacked intelligent metasurfaces (SIM) into cell-free (CF) massive multiple-input multiple-output (mMIMO) systems to enhance access point (AP) capabilities and address high…

Information Theory · Computer Science 2024-09-20 Enyu Shi , Jiayi Zhang , Yiyang Zhu , Jiancheng An , Chau Yuen , Bo Ai

In this paper, we investigate an reconfigurable intelligent surface (RIS)-aided integrated sensing and communication (ISAC) system. Our objective is to maximize the achievable sum rate of the multi-antenna communication users through the…

Signal Processing · Electrical Eng. & Systems 2024-02-09 Yasheng Jin , Hong Ren , Cunhua Pan , Zhiyuan Yu , Ruisong Weng , Boshi Wang , Gui Zhou , Yongchao He , Maged Elkashlan

Active reconfigurable intelligent surface (RIS) emerges as an effective technique to resist the double-fading attenuation of passive RIS. By embedding with power harvesting function, it further evolves to zero-power active RIS, which can…

Information Theory · Computer Science 2025-10-17 Xiao Zheng , Wenchi Cheng , Jingqing Wang , Zhuohui Yao , Jiangzhou Wang

Reconfigurable intelligent surface (RIS)-assisted communication have recently attracted the attention of the wireless communication community as a potential candidate for the next $6$-th generation (6G) of wireless networks. Various studies…

Signal Processing · Electrical Eng. & Systems 2022-05-18 Recep A. Tasci , Fatih Kilinc , Ertugrul Basar , George C. Alexandropoulos

This work considers a dual-functional radar and communication (DFRC) system with an active reconfigurable intelligent surface (RIS) and a potential eavesdropper. Our purpose is to maximize the secrecy rate (SR) of the system by jointly…

Signal Processing · Electrical Eng. & Systems 2024-02-06 Yang Zhang , Hong Ren , Cunhua Pan , Boshi Wang , Zhiyuan Yu , Ruisong Weng , Tuo Wu , Yongchao He

In next-generation wireless networks, reconfigurable intelligent surface (RIS)-assisted multiple-input multiple-output (MIMO) systems are foreseeable to support a large number of antennas at the transceiver as well as a large number of…

Information Theory · Computer Science 2023-01-24 Chang Cai , Xiaojun Yuan , Ying-Jun Angela Zhang

The reconfigurable intelligent surface (RIS) plays an important role in maintaining the connectivity in millimeter wave (mmWave) MIMO systems when the direct channel between the transceivers is blocked. However, it is difficult to acquire…

Signal Processing · Electrical Eng. & Systems 2021-03-04 Rafaela Schroeder , Jiguang He , Markku Juntti

Reconfigurable intelligent surfaces (RISs) have recently received widespread attention in the field of wireless communication. An RIS can be controlled to reflect incident waves from the transmitter towards the receiver; a feature that is…

Information Theory · Computer Science 2021-09-15 Jiangfeng Hu , Haifan Yin , Emil Björnson

Reconfigurable intelligent surfaces (RISs) have become a promising candidate for the development of future mobile systems. In the context of massive machine-type communications (mMTC), a RIS can be used to support the transmission from a…

Signal Processing · Electrical Eng. & Systems 2024-12-11 Sergi Liesegang , Alessio Zappone , Olga Muñoz , Antonio Pascual-Iserte

Reconfigurable intelligent surface (RIS) is considered to be an energy-efficient approach to reshape the wireless environment for improved throughput. Its passive feature greatly reduces the energy consumption, which makes RIS a promising…

Information Theory · Computer Science 2020-01-20 Keke Ying , Zhen Gao , Shanxiang Lyu , Yongpeng Wu , Hua Wang , Mohamed-Slim Alouini

This paper considers an active reconfigurable intelligent surface (RIS)-aided integrated sensing and communication (ISAC) system. We aim to maximize radar signal-to-interference-plus-noise-ratio (SINR) by jointly optimizing the beamforming…

Information Theory · Computer Science 2024-02-06 Zhiyuan Yu , Hong Ren , Cunhua Pan , Gui Zhou , Boshi Wang , Mianxiong Dong , Jiangzhou Wang

Low-cost passive intelligent reflecting surfaces (IRSs) have recently been envisioned as a revolutionary technology capable of reconfiguring the wireless propagation environment through carefully tuning reflection elements. This paper…

Signal Processing · Electrical Eng. & Systems 2021-09-14 Zhangjie Peng , Zhenkun Zhang , Cunhua Pan , Li Li , A. Lee Swindlehurst

Reconfigurable Intelligent Surfaces (RISs) are an emerging technology for future wireless communication systems, enabling improved coverage in an energy efficient manner. RISs are usually metasurfaces, constituting of two-dimensional…

Information Theory · Computer Science 2022-03-28 Konstantinos D. Katsanos , Nir Shlezinger , Mohammadreza F. Imani , George C. Alexandropoulos

In this paper, we propose and study a multi-functional reconfigurable intelligent surface (MF-RIS) architecture. In contrast to conventional single-functional RIS (SF-RIS) that only reflects signals, the proposed MF-RIS simultaneously…

Signal Processing · Electrical Eng. & Systems 2023-10-05 Wen Wang , Wanli Ni , Hui Tian , Yonina C. Eldar , Rui Zhang

In this paper, we investigate simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RIS), which enables to communicate with users both sides by transmitting signals to users forward and reflecting signals to…

Information Theory · Computer Science 2021-12-14 Ruitianyi Lu , Kehao Wang

This paper proposes a joint active and passive beamforming design for reconfigurable intelligent surface (RIS)-aided wireless communication systems, adopting a piece-wise near-field channel model. While a traditional near-field channel…

Information Theory · Computer Science 2024-06-24 Weijian Chen , Zai Yang , Zhiqiang Wei , Derrick Wing Kwan Ng , Michail Matthaiou

We consider a multiple-input multiple-output (MIMO) channel in the presence of a reconfigurable intelligent surface (RIS). Specifically, our focus is on analyzing the spatial multiplexing gains in line-of-sight and low-scattering MIMO…

Information Theory · Computer Science 2023-01-10 Giulio Bartoli , Andrea Abrardo , Nicolo Decarli , Davide Dardari , Marco Di Renzo

In this letter, we study the reconfigurable intelligent surfaces (RIS) aided full-duplex (FD) communication system. By jointly designing the active beamforming of two multi-antenna sources and passive beamforming of RIS, we aim to maximize…

Signal Processing · Electrical Eng. & Systems 2022-05-25 Yiru Wang , Pengxin Guan , Hongkang Yu , Yuping Zhao

Reconfigurable intelligent surface (RIS)-based communication networks promise to improve channel capacity and energy efficiency. However, the promised capacity gains could be negligible for passive RISs because of the double pathloss…

Information Theory · Computer Science 2022-06-30 Shayan Zargari , Azar Hakimi , Chintha Tellambura , Sanjeewa Herath