English
Related papers

Related papers: Parallel Factor Decomposition Channel Estimation i…

200 papers

Reconfigurable Intelligent Surfaces (RISs) are envisioned to play a key role in future wireless communications, enabling programmable radio propagation environments. They are usually considered as nearly passive planar structures that…

Signal Processing · Electrical Eng. & Systems 2022-02-14 Haiyang Zhang , Nir Shlezinger , Idban Alamzadeh , George C. Alexandropoulos , Mohammadreza F. Imani , Yonina C. Eldar

For downlink massive multiple-input multiple-output (MIMO) operating in time-division duplex protocol, users can decode the signals effectively by only utilizing the channel statistics as long as channel hardening holds. However, in a…

Information Theory · Computer Science 2022-05-17 Tung T. Vu , Trinh Van Chien , Canh T. Dinh , Hien Quoc Ngo , Michail Matthaiou

A significant increase in the number of reconfigurable intelligent surface (RIS) elements results in a spherical wavefront in the near field of extremely large-scale RIS (XL-RIS). Although the channel matrix of the cascaded two-hop link may…

Signal Processing · Electrical Eng. & Systems 2023-11-14 Zixing Tang , Yuanbin Chen , Ying Wang , Tianqi Mao , Qingqing Wu , Marco Di Renzo , Lajos Hanzo

The reconfigurable intelligent surface (RIS) is one of the promising technologies contributing to the next generation smart radio environment. A novel physics-based RIS channel model is proposed. Particularly, we consider the RIS and the…

Signal Processing · Electrical Eng. & Systems 2020-08-04 Jiaqi Xu , Yuanwei Liu

In this paper, we propose a novel two-stage based uplink channel estimation strategy with reduced pilot overhead and error propagation for a reconfigurable intelligent surface (RIS)-aided multi-user (MU) millimeter wave (mmWave) system.…

Signal Processing · Electrical Eng. & Systems 2022-08-24 Zhendong Peng , Cunhua Pan , Gui Zhou , Hong Ren

The use of multiple Reconfigurable Intelligent Sur- faces (RIS) has gained attention in 6G networks to enhance coverage. However, the feasibility of deploying multiple RIS relies on efficient channel estimation and reduced pilot overhead.…

Information Theory · Computer Science 2025-11-25 Roberto C. G. Porto , Rodrigo C. de Lamare

Reconfigurable intelligent surface (RIS) is a recent low-cost and energy-efficient technology with potential applicability for future wireless communications. Performance gains achieved by employing RIS directly depend on accurate channel…

Signal Processing · Electrical Eng. & Systems 2024-12-24 Paulo R. B. Gomes , Amarilton L. Magalhães , André L. F. de Almeida

Reconfigurable intelligent surface (RIS) is very promising for wireless networks to achieve high energy efficiency, extended coverage, improved capacity, massive connectivity, etc. To unleash the full potentials of RIS-aided communications,…

Information Theory · Computer Science 2022-01-03 Yabo Guo , Peng Sun , Zhengdao Yuan , Chongwen Huang , Qinghua Guo , Zhongyong Wang , Chau Yuen

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

Reconfigurable intelligent surface (RIS) has emerged as a promising technology for improving capacity and extending coverage of wireless networks. In this work, we consider RIS-aided millimeter wave (mmWave) multiple-input and…

Information Theory · Computer Science 2023-04-17 Yabo Guo , Peng Sun , Zhengdao Yuan , Qinghua Guo , Zhongyong Wang

Recent research has focused on reconfigurable intelligent surface (RIS)-assisted cell-free systems with the goal of enhancing coverage and lowering the cost of cell-free networks. However, current research makes the assumption that the…

Signal Processing · Electrical Eng. & Systems 2022-07-29 Songjie Yang , Chenfei Xie , Mingwei Wang , Zhongpei Zhang

Flexible Intelligent Metasurfaces (FIMs) enable wireless systems to adapt their three-dimensional geometry through morphing, thereby providing new spatial degrees of freedom. However, continuous deformation complicates the accurate…

Signal Processing · Electrical Eng. & Systems 2026-05-29 Vinícius L. Romano , André L. F. de Almeida , Daniel C. Araújo

Reconfigurable intelligent surfaces (RISs) have been proposed recently as new technology to tune the wireless propagation channels in real-time. However, most of the current works assume single-RIS (S-RIS)-aided systems, which can be…

Signal Processing · Electrical Eng. & Systems 2021-09-21 Khaled Ardah , Sepideh Gherekhloo , André L. F. de Almeida , Martin Haardt

The integration of reconfigurable intelligent surfaces (RIS) with extremely large multiple-input multiple-output (MIMO) arrays at the base station has emerged as a key enabler for enhancing wireless network performance. However, this setup…

Signal Processing · Electrical Eng. & Systems 2025-08-05 Ahmad Dkhan , Simon Tarboush , Hadi Sarieddeen , Tareq Y. Al-Naffouri

Reconfigurable intelligent surface (RIS) has been explored as a supportive technology for wireless communication since around 2019. While the literature highlights the potential of RIS in different modern applications, two key issues have…

Signal Processing · Electrical Eng. & Systems 2025-06-10 Daniel C. Alcantara , Daniel V. C. de Oliveira , Gilderlan T. de Araújo , Paulo R. B. Gomes , André L. F. de Almeida

Double-reconfigurable intelligent surface (RIS) is a promising technique, achieving a substantial gain improvement compared to single-RIS techniques. However, in double-RIS-aided systems, accurate channel estimation is more challenging than…

Information Theory · Computer Science 2022-11-30 Songjie Yang , Wanting Lyu , Yue Xiu , Zhongpei Zhang , Chau Yuen

The deployment of reconfigurable intelligent surfaces (RISs) in a communication system provides control over the propagation environment, which facilitates the augmentation of a multitude of communication objectives. As these performance…

Signal Processing · Electrical Eng. & Systems 2023-05-04 Bilal Ahmad , Kevin Weinberger , Aydin Sezgin , Bilal Zafar , Martin Haardt

Cell-Free Massive multiple-input multiple-output (MIMO) and reconfigurable intelligent surface (RIS) are two promising technologies for application to beyond-5G networks. This paper considers Cell-Free Massive MIMO systems with the…

Information Theory · Computer Science 2021-12-20 Trinh Van Chien , Hien Quoc Ngo , Symeon Chatzinotas , Marco Di Renzo , Björn Ottersten

Deploying multiple beyond diagonal reconfigurable intelligent surfaces (BD-RISs) can potentially improve the communication performance thanks to inter-element connections of each BD-RIS and inter-surface cooperative beamforming gain among…

Signal Processing · Electrical Eng. & Systems 2026-02-23 Junyuan Gao , Shuowen Zhang , Liang Liu

This work studies the net sum-rate performance of a distributed reconfigurable intelligent surfaces (RISs)-assisted multi-user multiple-input-single-output (MISO) downlink communication system under imperfect instantaneous-channel state…

Signal Processing · Electrical Eng. & Systems 2023-08-10 Bayan Al-Nahhas , Qurrat-UI-Ain Nadeem , Aryan Kaushik , Anas Chaaban