English
Related papers

Related papers: A New Old Idea: Beam-Steering Reflectarrays for Ef…

200 papers

We propose a power- and hardware-efficient, pragmatic, modular, multiuser/multibeam array-fed RIS architecture particularly suited to operate in very high frequency bands (high mmWave and sub-THz), where channels are typically sparse in the…

Signal Processing · Electrical Eng. & Systems 2024-10-10 Krishan Kumar Tiwari , Giuseppe Caire

We present a novel, power and hardware efficient, antenna system leveraging the eigenmodes of the over-the-air propagation matrix from an active multi-antenna feeder (AMAF) to a large reflective intelligent surface (RIS), both configured as…

Signal Processing · Electrical Eng. & Systems 2023-10-26 Krishan K. Tiwari , Giuseppe Caire

In our previous work [2], we introduced a hardware- and power-efficient architecture for hybrid digital-analog (HDA) multiuser MIMO (MU-MIMO) based on stacking identical basic modules. Each module consists of a small active multi-antenna…

Signal Processing · Electrical Eng. & Systems 2026-03-09 Krishan Kumar Tiwari , Giuseppe Caire

Reconfigurable intelligent surfaces (RISs) have been deemed as one of potential components of future wireless communication systems because they can adaptively manipulate the wireless propagation environment with low-cost passive devices.…

Signal Processing · Electrical Eng. & Systems 2022-03-23 Yanan Ma , Rang Liu , Yang Liu , Ming Li , Qian Liu

Intelligent reflecting surface (IRS) is envisioned to play a significant role in future wireless communication systems as an effective means of reconfiguring the radio signal propagation environment. In this paper, we study a new multi-IRS…

Information Theory · Computer Science 2021-08-25 Weidong Mei , Rui Zhang

In this paper, we investigate the potential of employing reconfigurable intelligent surface (RIS) in integrated sensing and communication (ISAC) systems. In particular, we consider an RIS-assisted ISAC system in which a multi-antenna base…

Signal Processing · Electrical Eng. & Systems 2023-01-27 Rang Liu , Ming Li , A. Lee Swindlehurst

Reconfigurable intelligent surface (RIS) has been deemed as one of potential components of future wireless communication systems because it can adaptively manipulate the wireless propagation environment with low-cost passive devices.…

Signal Processing · Electrical Eng. & Systems 2024-10-28 Yanan Ma , Ming Li , Yang Liu , Qingqing Wu , Qian Liu

Reconfigurable intelligent surface (RIS) provides a promising way to build the programmable wireless transmission environments in the future. Owing to the large number of reflecting elements used at the RIS, joint optimization for the…

Information Theory · Computer Science 2021-01-11 Xiaoyan Ma , Shuaishuai Guo , Haixia Zhang , Yuguang Fang , Dongfeng Yuan

Reconfigurable intelligent surface (RIS) has emerged as a cost-effective solution for green communications in 6G. However, its further extensive use has been greatly limited due to its fully passive characteristics. Considering the…

Information Theory · Computer Science 2025-01-15 Jintao Wang , Chengzhi Ma , Shiqi Gong , Xi Yang , Shaodan Ma

Reconfigurable intelligent surfaces (RIS)-assisted cell-free massive multiple-input multiple-output (CF mMIMO) systems have emerged as a promising technology for sixth-generation communication systems. These systems capitalize on RIS to…

Signal Processing · Electrical Eng. & Systems 2024-12-24 Yu Lu , Jiayi Zhang , Enyu Shi , Peng Zhang , Derrick Wing Kwan Ng , Dusit Niyato , Bo Ai

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

Reconfigurable intelligent surfaces (RISs) can be densely deployed in the environment to create multi-reflection line-of-sight (LoS) links for signal coverage enhancement. However, conventional reflection-only RISs can only achieve…

Signal Processing · Electrical Eng. & Systems 2025-05-21 Bonan An , Weidong Mei , Yuanwei Liu , Dong Wang , Zhi Chen

Although reconfigurable intelligent surfaces (RISs) can improve the performance of wireless networks by smartly reconfiguring the radio environment, existing passive RISs face two key challenges, i.e., double-fading attenuation and…

Signal Processing · Electrical Eng. & Systems 2023-10-05 Wen Wang , Wanli Ni , Hui Tian , Naofal Al-Dhahir

Space-fed large antenna arrays offer superior efficiency, simplicity, and reductions in size, weight, power, and cost (SWaP-C) compared to constrained-feed systems. Historically, horn antennas have been used for space feeding, but they…

Signal Processing · Electrical Eng. & Systems 2025-05-15 Krishan Kumar Tiwari , Thomas Flisgen , Wolfgang Heinrich , Giuseppe Caire

Reconfigurable intelligent surface (RIS) provides a promising way to proactively augment propagation environments for better transmission performance in wireless communications. Existing multi-RIS works mainly focus on link-level…

Networking and Internet Architecture · Computer Science 2024-05-22 Xiaoyan Ma , Haixia Zhang , Xianhao Chen , Yuguang Fangmand Dongfeng Yuan

The concept of reconfigurable intelligent surface (RIS) has been proposed to change the propagation of electromagnetic waves, e.g., reflection, diffraction, and refraction. To accomplish this goal, the phase values of the discrete RIS units…

Signal Processing · Electrical Eng. & Systems 2019-11-11 Jiguang He , Henk Wymeersch , Tachporn Sanguanpuak , Olli Silvén , Markku Juntti

In this work, we propose a new single-RF MIMO architecture which enjoys high scalability and energy-efficiency. The transmitter in this proposal consists of a single RF illuminator radiating towards a reflecting surface. Each element on the…

Information Theory · Computer Science 2020-03-20 Ali Bereyhi , Vahid Jamali , Ralf R. Müller , Antonia M. Tulino , Georg Fischer , Robert Schober

This paper investigates a modular beamforming framework for reconfigurable intelligent surface (RIS)-aided multi-user (MU) communications in the near-field regime, built upon a novel antenna architecture integrating an active multi-antenna…

Signal Processing · Electrical Eng. & Systems 2025-08-13 Giulia Torcolacci , Malte Schellmann , Davide Dardari

As communication systems that employ millimeter wave (mmWave) frequency bands must use large antenna arrays to overcome the severe propagation loss of mmWave signals, hybrid beamforming has been considered as an integral component of mmWave…

Signal Processing · Electrical Eng. & Systems 2022-06-28 Sung Hyuck Hong , Jaeyong Park , Sung-Jin Kim , Junil Choi

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
‹ Prev 1 2 3 10 Next ›