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Related papers: RIS-aided Near-Field MIMO Communications: Codebook…

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Extremely large-scale massive multiple-input-multiple-output (XL-MIMO) is regarded as a promising technology for next-generation communication systems. In order to enhance the beamforming gains, codebook-based beam training is widely…

Information Theory · Computer Science 2022-09-29 Wang Liu , Hong Ren , Cunhua Pan , Jiangzhou Wang

The paper studies a reconfigurable intelligent surface (RIS)-assisted multi-user uplink massive multiple-input multiple-output (MIMO) system with imperfect hardware. At the RIS, the paper considers phase noise, while at the base station,…

Information Theory · Computer Science 2022-08-18 Zhangjie Peng , Xianzhe Chen , Cunhua Pan , Maged Elkashlan , Jiangzhou Wang

A novel reconfigurable intelligent surface (RIS)-aided hybrid reflection/transmitter design is proposed for achieving information exchange in cross-media communications. In pursuit of the balance between energy efficiency and low-cost…

Signal Processing · Electrical Eng. & Systems 2022-11-08 Mingming Wu , Yue Xiao , Yulan Gao , Ming Xiao

Practical hardware limitations often impose a reduced number of available phase shifts at the elements of a reconfigurable intelligent surface (RIS). Most works often assume continuous phase-shits at the RIS elements for the transmit and…

Information Theory · Computer Science 2023-04-20 Nuno Souto

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 studies a reconfigurable intelligent surface (RIS)-assisted cell-free massive multiple-input multiple-output (CF-mMIMO) system with multiple RISs. Joint design of transmit precoding, RIS coefficients, and receive combining is…

Signal Processing · Electrical Eng. & Systems 2025-10-21 Navid Reyhanian , Reza Ghaderi Zefreh , Parisa Ramezani , Emil Bjornson

Reconfigurable intelligent surface (RIS) provides a promising way to build programmable wireless transmission environments. Owing to the massive number of controllable reflecting elements on the surface, RIS is capable of providing…

Information Theory · Computer Science 2022-10-03 Xiaoyan Ma , Yuguang Fang , Haixia Zhang , Shuaishuai Guo , Dongfeng Yuan

The plethora of wirelessly connected devices, whose deployment density is expected to largely increase in the upcoming sixth Generation (6G) of wireless networks, will naturally necessitate substantial advances in multiple access schemes.…

Information Theory · Computer Science 2024-10-29 Konstantinos D. Katsanos , Paolo Di Lorenzo , George C. Alexandropoulos

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

This paper explores the performance of reconfigurable intelligent surface (RIS) assisted spatial modulation (SM) downlink communication systems, focusing on the average bit error probability (ABEP). Notably, in scenarios with a large number…

Information Theory · Computer Science 2024-04-02 Xusheng Zhu , Qingqing Wu , Wen Chen

The reconfigurable intelligent surface (RIS) technology is a promising enabler for millimeter wave (mmWave) wireless communications, as it can potentially provide spectral efficiency comparable to the conventional massive multiple-input…

Information Theory · Computer Science 2022-02-22 Xuemeng Zhou , Zhiyu Yang , Tianyi Zhang , Yi Jiang

In conventional colocated multiple-input multiple-output (MIMO) radars, practical waveform constraints including peak-to-average power ratio, constant or bounded modulus lead to a significant performance reduction of transmit beampattern,…

Signal Processing · Electrical Eng. & Systems 2024-10-08 Shengyao Chen , Minghui He , Longyao Ran , Hongtao Li , Feng Xi , Sirui Tian , Zhong Liu

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

In this paper, we consider and study a cell-free massive MIMO (CF-mMIMO) system aided with reconfigurable intelligent surfaces (RISs), where a large number of access points (APs) cooperate to serve a smaller number of users with the help of…

Information Theory · Computer Science 2021-05-17 Bayan Al-Nahhas , Mohanad Obeed , Anas Chaaban , Md. Jahangir Hossain

The ever-growing popularity and rapid improving of artificial intelligence (AI) have raised rethinking on the evolution of wireless networks. Mobile edge computing (MEC) provides a natural platform for AI applications since it provides rich…

Information Theory · Computer Science 2021-02-08 Shanfeng Huang , Shuai Wang , Rui Wang , Miaowen Wen , Kaibin Huang

In this letter, we derive an expression for the achievable rate in a multiple-input multiple-output (MIMO) system assisted by a beyond-diagonal reconfigurable intelligent surface (BD-RIS) when the channels to and from the BD-RIS are…

Information Theory · Computer Science 2025-04-11 Ignacio Santamaria , Jesus Gutierrez , Mohammad Soleymani , Eduard Jorswieck

The performance of wireless communication systems is fundamentally constrained by random and uncontrollable wireless channels. Recently, reconfigurable intelligent surfaces (RIS) has emerged as a promising solution to enhance wireless…

Signal Processing · Electrical Eng. & Systems 2023-12-29 Xiaohao Mo , Lin Gui , Kai Ying , Xichao Sang , Xiaqing Diao

Reconfigurable intelligent surfaces (RIS) and flexible intelligent metasurfaces (FIM) have been widely adopted in multi-user wireless communication systems to enhance channel quality through simultaneous transmission and reflection of…

Signal Processing · Electrical Eng. & Systems 2025-09-23 Ayla Eftekhari , Maryam Cheraghy , Armin Farhadi , Mohammad Robat Mili , Qingqing Wu

Intelligent surfaces that reshape electromagnetic waves are regarded as disruptive technologies for wireless networks. However, existing designs sit at two costly extremes: dynamic reconfigurable intelligent surfaces (RISs) offer fine beam…

Signal Processing · Electrical Eng. & Systems 2025-11-24 Ziyuan Zheng , Qingqing Wu , Wen Chen , Weiren Zhu , Ying Gao

Recently, simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) have received significant research interest. The employment of large STAR-RIS and high-frequency signaling inevitably make the near-field…

Information Theory · Computer Science 2023-06-27 Haochen Li , Yuanwei Liu , Xidong Mu , Yue Chen , Zhiwen Pan , Yonina C. Eldar