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Related papers: Broad Beam Reflection for RIS-Assisted MIMO System…

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In this correspondence, we present a reconfigurable intelligent surface (RIS) that reflects an incident signal to the desired direction, depending on the pulse width. This unique reconfigurability emerges by virtue of the transient response…

The amalgamation of cell-free networks and reconfigurable intelligent surface (RIS) has become a prospective technique for future sixth-generation wireless communication systems. In this paper, we focus on the precoding and beamforming…

Information Theory · Computer Science 2023-11-23 Peng Zhang , Jiayi Zhang , Huahua Xiao , Xiaodan Zhang , Derrick Wing Kwan Ng , Bo Ai

Large-scale antenna arrays employed by the base station (BS) constitute an essential next-generation communications technique. However, due to the constraints of size, cost, and power consumption, it is usually considered unrealistic to use…

Information Theory · Computer Science 2021-10-28 Kunzan Liu , Zijian Zhang , Linglong Dai , Lajos Hanzo

The spectrum shift from the sub-6G band to the high-frequency band has posed an ever-increasing demand on the paradigm shift from narrowband beamforming to wideband beamforming. Despite recent research efforts, the problem of wideband…

Computational Engineering, Finance, and Science · Computer Science 2024-07-09 Xiaowei Qian , Xiaoling Hu , Chenxi Liu , Mugen Peng

Reconfigurable intelligent surfaces (RISs) have attracted great attention as a potential beyond 5G technology. These surfaces consist of many passive elements of metamaterials whose impedance can be controllable to change the phase,…

Information Theory · Computer Science 2021-09-09 Özlem Tuğfe Demir , Emil Björnson

Reconfigurable intelligent surface (RIS)-aided cell-free (CF) massive multiple-input multiple-output (mMIMO) is a promising technology for further improving spectral efficiency (SE) with low cost and power consumption. However, conventional…

Information Theory · Computer Science 2025-12-02 Yizhuo Li , Jiakang Zheng , Bokai Xu , Yiyang Zhu , Jiayi Zhang , Dusit Niyato , Bo Ai

Cell-free massive MIMO (multiple-input multiple-output) is a promising network architecture for beyond 5G systems, which can particularly offer more uniform data rates across the coverage area. Recent works have shown how reconfigurable…

Signal Processing · Electrical Eng. & Systems 2024-09-25 Özlem Tuğfe Demir , Emil Björnson

The adoption of a Reconfigurable Intelligent Surface (RIS) for downlink multi-user communication from a multi-antenna base station is investigated in this paper. We develop energy-efficient designs for both the transmit power allocation and…

Information Theory · Computer Science 2022-06-23 Chongwen Huang , Alessio Zappone , George C. Alexandropoulos , Mérouane Debbah , Chau Yuen

This paper considers the application of reconfigurable intelligent surfaces (RISs) (a.k.a. intelligent reflecting surfaces (IRSs)) to assist multiuser multiple-input multiple-output (MIMO) uplink transmission from several multi-antenna user…

Information Theory · Computer Science 2021-09-14 Li You , Jiayuan Xiong , Yufei Huang , Derrick Wing Kwan Ng , Cunhua Pan , Wenjin Wang , Xiqi Gao

Recently, the reconfigurable intelligent surface (RIS), benefited from the breakthrough on the fabrication of programmable meta-material, has been speculated as one of the key enabling technologies for the future six generation (6G)…

Information Theory · Computer Science 2022-06-23 Chongwen Huang , Ronghong Mo , Chau Yuen

Reconfigurable intelligent surface (RIS) is a new paradigm that has great potential to achieve cost-effective, energy-efficient information modulation for wireless transmission, by the ability to change the reflection coefficients of the…

Signal Processing · Electrical Eng. & Systems 2020-07-07 Wankai Tang , Jun Yan Dai , Ming Zheng Chen , Kai-Kit Wong , Xiao Li , Xinsheng Zhao , Shi Jin , Qiang Cheng , Tie Jun Cui

This paper considers wireless communication assisted by a reconfigurable intelligent surface (RIS), focusing on the two-timescale approach, in which the RIS phase shifts are optimized based on channel statistics to mitigate the overheads…

Information Theory · Computer Science 2025-07-30 Masoud Sadeghian , Angel Lozano , Gabor Fodor

Reconfigurable intelligent surfaces (RIS) as an effective technique for intelligently manipulating channel paths through reflection to serve desired users. Full-duplex (FD) systems, enabling simultaneous transmission and reception from a…

Information Theory · Computer Science 2023-11-08 Li-Hsiang Shen , Chia-Jou Ku , Kai-Ten Feng

Cell-free systems can effectively eliminate the inter-cell interference by enabling multiple base stations (BSs) to cooperatively serve users without cell boundaries at the expense of high costs of hardware and power sources due to the…

Information Theory · Computer Science 2020-11-18 Yutong Zhang , Boya Di , Hongliang Zhang , Jinlong Lin , Yonghui Li , Lingyang Song

Reconfigurable intelligent surfaces (RISs) can improve the capacity of wireless communication links by passively beamforming the impinging signals in desired directions. This feature has been demonstrated both analytically and…

Signal Processing · Electrical Eng. & Systems 2025-01-23 Emil Björnson , Özlem Tuğfe Demir

We consider transmit beamforming and reflection pattern design in reconfigurable intelligent surface (RIS)-assisted integrated sensing and communication (ISAC) systems to jointly precode communication symbols and radar waveforms. We treat…

Signal Processing · Electrical Eng. & Systems 2022-06-16 R. S. Prasobh Sankar , Sundeep Prabhakar Chepuri , Yonina C. Eldar

Reconfigurable intelligent surface (RIS) can improve the communications between a source and a destination. Recently, continuous aperture RIS is proved to have better communication performance than discrete aperture RIS and has received…

Signal Processing · Electrical Eng. & Systems 2022-10-04 Yuhua Jiang , Feifei Gao , Mengnan Jian , Shun Zhang , Wei Zhang

Wireless communications aided by reconfigurable intelligent surfaces (RISs) is a promising way to improve the coverage for cellular users. The controlled reflection of signals from RISs is especially useful in mm-wave/THz networks when the…

Information Theory · Computer Science 2023-03-14 Vikrant Malik , Gourab Ghatak , Abhishek K. Gupta , Sanket S. Kalamkar

In this paper, we consider a reconfigurable intelligent surface (RIS)-assisted two-way relay network, in which two users exchange information through the base station (BS) with the help of an RIS. By jointly designing the phase shifts at…

Information Theory · Computer Science 2021-05-11 Jun Wang , Ying-Chang Liang , Jingon Joung , Xiaojun Yuan , Xinguo Wang

Reconfigurable intelligent surface (RIS) is a revolutionary technology for sixth-generation (6G) networks owing to its ability to manipulate wireless environments. As a frequency-selective device, RIS can only effectively shape the…

Information Theory · Computer Science 2022-11-01 Sifan Liu , Rang Liu , Ming Li , Yang Liu , Qian Liu