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Related papers: Beamforming Design for Beyond Diagonal RIS-Aided C…

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Stacked intelligent metasurface (SIM) has emerged as a technology enabling wave domain beamforming through multiple stacked reconfigurable intelligent surfaces (RISs). SIM has been implemented so far with diagonal RIS (D-RIS), while SIM…

Information Theory · Computer Science 2024-05-14 Matteo Nerini , Bruno Clerckx

In this letter, we present in detail the system-level modeling of reconfigurable intelligent surface (RIS)-assisted cellular systems by considering a 3-dimensional channel model between base station, RIS, and user. We prove that the optimal…

Information Theory · Computer Science 2023-05-03 Pavan Reddy M. , SaiDhiraj Amuru , Kiran Kuchi

In cell-free multiple input multiple output (MIMO) networks, multiple base stations (BSs) collaborate to achieve high spectral efficiency. Nevertheless, high penetration loss due to large blockages in harsh propagation environments is often…

Information Theory · Computer Science 2023-03-16 Chen Chen , Sai Xu , Jiliang Zhang , Jie Zhang

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

The cell-free networking paradigm constitutes a revolutionary architecture for future generations of wireless networks, which has been recently considered in synergy with Reconfigurable Intelligent Surfaces (RISs), a promising…

Signal Processing · Electrical Eng. & Systems 2026-01-15 Konstantinos D. Katsanos , George C. Alexandropoulos

This work focuses on the synergy of rate-splitting multiple access (RSMA) and beyond diagonal reconfigurable intelligent surface (BD-RIS) to enlarge the coverage, improve the performance, and save on antennas. Specifically, we employ a…

Information Theory · Computer Science 2024-01-05 Hongyu Li , Shanpu Shen , Bruno Clerckx

Beyond-diagonal reconfigurable intelligent surfaces (BD-RISs) extend conventional diagonal RISs by allowing inter-element coupling, thereby enlarging the set of attainable scattering matrices and improving the achievable signal-to-noise…

Signal Processing · Electrical Eng. & Systems 2026-05-08 Konstantinos Ntougias , Ioannis Krikidis

This paper investigates reconfigurable intelligent surface (RIS)-assisted secure multiuser communication systems subject to hardware impairments (HIs). We jointly optimize the beamforming vectors at the base station (BS) and the phase…

Information Theory · Computer Science 2022-10-12 Zhangjie Peng , Ruisong Weng , Cunhua Pan , Gui Zhou , Marco Di Renzo , A. Lee Swindlehurst

Reconfigurable intelligent surfaces (RISs) have emerged as a spectrum- and energy-efficient technology to enhance the coverage of wireless communications within the upcoming 6G networks. Recently, novel extensions of this technology,…

Signal Processing · Electrical Eng. & Systems 2024-06-07 Mostafa Samy , Hayder Al-Hraishawi , Abuzar B. M. Adam , Konstantinos Ntontin , Symeon Chatzinotas , Björn Otteresten

Reconfigurable intelligent surface (RIS) as an emerging cost-effective technology can enhance the spectrum- and energy-efficiency of wireless networks. In this paper, we consider an RIS-aided green edge inference system, where the inference…

Signal Processing · Electrical Eng. & Systems 2024-10-30 Sheng Hua , Yong Zhou , Kai Yang , Yuanming Shi

Although reconfigurable intelligent surfaces (RISs) have demonstrated the potential to boost network capacity and expand coverage by adjusting their electromagnetic properties, existing RIS architectures have certain limitations, such as…

Signal Processing · Electrical Eng. & Systems 2024-05-28 Wanli Ni , Ailing Zheng , Wen Wang , Dusit Niyato , Naofal Al-Dhahir , Merouane Debbah

Reconfigurable intelligent surface (RIS) is an attractive technology to improve the transmission rate of millimetre-wave (mmWave) communication systems. The previous {research} on RIS technology mainly focused on improving the transmission…

Signal Processing · Electrical Eng. & Systems 2022-11-01 Yunis Xanthos , Wanting Lyu , Songjie Yang , Chadi Assi , Xianbing Zou , Ning Wei

Recent advances in reconfigurable antennas have led to the new concept of the fluid antenna system (FAS) for shape and position flexibility, as another degree of freedom for wireless communication enhancement. This paper explores the…

Signal Processing · Electrical Eng. & Systems 2025-04-15 Jiangong Chen , Yue Xiao , Zhendong Peng , Jing Zhu , Xia Lei , Christos Masouros , Kai-Kit Wong

Integrating the reconfigurable intelligent surface in a cell-free (RIS-CF) network is an effective solution to improve the capacity and coverage of future wireless systems with low cost and power consumption. The reflecting coefficients of…

Signal Processing · Electrical Eng. & Systems 2021-03-10 Quang Nhat Le , Van-Dinh Nguyen , Octavia A. Dobre , Ruiqin Zhao

Mutual Coupling (MC) is an unavoidable feature in Reconfigurable Intelligent Surfaces (RISs) with sub-wavelength inter-element spacing. Its inherent presence naturally leads to non-local RIS structures, which can be efficiently described…

Information Theory · Computer Science 2024-04-09 Dilki Wijekoon , Amine Mezghani , George C. Alexandropoulos , Ekram Hossain

A near-field wideband beamforming scheme is investigated for reconfigurable intelligent surface (RIS) assisted multiple-input multiple-output (MIMO) systems, in which a deep learning-based end-to-end (E2E) optimization framework is proposed…

Information Theory · Computer Science 2025-01-30 Ji Wang , Jian Xiao , Yixuan Zou , Wenwu Xie , Yuanwei Liu

Reconfigurable intelligent surfaces enhance wireless systems by reshaping propagation environments. However, dynamic metasurfaces (MSs) with numerous phase-shift elements incur undesired control and hardware costs. In contrast, static MSs…

Signal Processing · Electrical Eng. & Systems 2024-12-30 Ziyuan Zheng , Qingqing Wu , Wen Chen , Xiangming Wu , Weiren Zhu

Massive multiple-input multiple-output (MIMO) and reconfigurable intelligent surface (RIS) are two promising technologies for 5G-and-beyond wireless networks, capable of providing large array gain and multiuser spatial multiplexing. Without…

Information Theory · Computer Science 2021-09-07 Trinh Van Chien , Hien Quoc Ngo , Symeon Chatzinotas , Björn Ottersten

In this paper, the problem of maximizing the sum of data rates of all users in an intelligent reflecting surface (IRS)-assisted millimeter wave multicast multiple-input multiple-output communication system is studied. In the considered…

Signal Processing · Electrical Eng. & Systems 2022-08-16 Songling Zhang , Zhaohui Yang , Mingzhe Chen , Danpu Liu , Kai-Kit Wong , H. Vincent Poor

In this paper, we study the problem of joint active and passive beamforming for reconfigurable intelligent surface (RIS)-assisted massive multiple-input multiple-output systems towards the extension of the wireless cellular coverage in 3D,…

Signal Processing · Electrical Eng. & Systems 2023-12-18 Yu Tian , Ahmed Alhammadi , Jiguang He , Aymen Fakhreddine , Faouzi Bader