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This paper presents a reconfigurable intelligent sensing surface (RISS) that combines passive and active elements to achieve simultaneous reflection and direction of arrival (DOA) estimation tasks. By utilizing DOA information from the RISS…

Information Theory · Computer Science 2023-12-01 Cheng Luo , Jie Hu , Luping Xiang , Kun Yang

Intelligent reflective surface (IRS) is an emergent technology for future wireless communications. It consists of a large 2D array of passive scattering elements that control the electromagnetic properties of radio-frequency waves so that…

Signal Processing · Electrical Eng. & Systems 2020-01-22 Gilderlan T. de Araújo , André L. F. de Almeida

The fluid antenna concept represents shape-flexible and position-flexible antenna technologies designed to enhance wireless communication applications. In this paper, we apply this concept to reconfigurable intelligent surfaces (RISs),…

Signal Processing · Electrical Eng. & Systems 2025-02-25 Abdelhamid Salem , Kai-Kit Wong , George Alexandropoulos , Chan-Byoung Chae , Ross Murch

Reconfigurable Intelligent Surfaces (RISs) have been recently considered as an energy-efficient solution for future wireless networks due to their fast and low-power configuration, which has increased potential in enabling massive…

Information Theory · Computer Science 2022-06-27 Li Wei , Chongwen Huang , George C. Alexandropoulos , Chau Yuen , Zhaoyang Zhang , Mérouane Debbah

Due to the passive nature of Intelligent Reflecting Surface (IRS), channel estimation is a fundamental challenge in IRS-aided wireless networks. Particularly, as the number of IRS reflecting elements and/or that of IRS-served users…

Information Theory · Computer Science 2020-08-04 Xinrong Guan , Qingqing Wu , Rui Zhang

This paper proposes a scalable channel estimation and reflection optimization framework for reconfigurable intelligent surface (RIS)-enhanced orthogonal frequency division multiplexing (OFDM) systems. Specifically, the proposed scheme…

Information Theory · Computer Science 2021-10-26 Jiancheng An , Qingqing Wu , Chau Yuen

Reconfigurable intelligent surfaces (RISs), with the potential to realize a smart radio environment, have emerged as an energy-efficient and a cost-effective technology to support the services and demands foreseen for coming decades. By…

Information Theory · Computer Science 2021-07-13 Sarah Basharat , Syed Ali Hassan , Haris Pervaiz , Aamir Mahmood , Zhiguo Ding , Mikael Gidlund

Channel state information (CSI) is essential to unlock the potential of reconfigurable intelligent surfaces (RISs) in wireless communication systems. Since massive RIS elements are typically implemented without baseband signal processing…

Signal Processing · Electrical Eng. & Systems 2025-09-03 Weicong Chen , Jiajia Guo , Yiming Cui , Xiao Li , Shi Jin

A reconfigurable intelligent surface (RIS) can shape the radio propagation environment by virtue of changing the impinging electromagnetic waves towards any desired directions, thus, breaking the general Snell's reflection law. However, the…

Signal Processing · Electrical Eng. & Systems 2021-01-15 Jiguang He , Henk Wymeersch , Markku Juntti

Orthogonal multi-user multiple-input multiple-output (MU-MIMO) channels allow for optimum performance with simplified precoding/equalization, and they achieve maximum multiplexing gain which is shared fairly among users. Reconfigurable…

Information Theory · Computer Science 2023-05-01 Juan Vidal Alegria , Fredrik Rusek

Integrated sensing and communication (ISAC) is recognized as a promising technology with great potential in saving hardware and spectrum resources, since it simultaneously realizes radar detection and user communication functions in the…

Signal Processing · Electrical Eng. & Systems 2023-02-22 Qi Zhu , Ming Li , Rang Liu , Qian Liu

Reconfigurable intelligent surfaces (RISs), an emerging technology proposed for inclusion in next generation wireless communication systems, are programmable surfaces that can adaptively reflect incident electromagnetic radiation in…

Signal Processing · Electrical Eng. & Systems 2025-12-30 Miguel Saavedra-Melo , Benjamin Bradshaw , Vanessa Yao , Ender Ayanoglu , Lee Swindlehurst , Filippo Capolino

With the rapid development of Internet of Things (IoT), massive machine-type communication has become a promising application scenario, where a large number of devices transmit sporadically to a base station (BS). Reconfigurable intelligent…

Information Theory · Computer Science 2021-01-26 Shuhao Xia , Yuanming Shi , Yong Zhou , Xiaojun Yuan

Active reconfigurable intelligent surfaces (RISs) can improve the performance of integrated sensing and communication (ISAC), and therefore enable simultaneous data transmission and target sensing. However, when the line-of-sight (LoS) link…

Signal Processing · Electrical Eng. & Systems 2024-10-17 Ahmed Magbool , Vaibhav Kumar , Mark F. Flanagan

Hybrid Reconfigurable Intelligent Surfaces (HRISs), which are capable of simultaneous programmable reflections and sensing, are expected to play a significant role in future wireless networks, enabling various Integrated Sensing and…

Signal Processing · Electrical Eng. & Systems 2022-10-28 Jiguang He , Aymen Fakhreddine , George C. Alexandropoulos

Intelligent reflecting surface (IRS) has drawn a lot of attention recently as a promising new solution to achieve high spectral and energy efficiency for future wireless networks. By utilizing massive low-cost passive reflecting elements,…

Information Theory · Computer Science 2022-10-17 Ming-Min Zhao , Qingqing Wu , Min-Jian Zhao , Rui Zhang

The reconfigurable intelligent surface (RIS) technology has attracted interest due to its promising coverage and spectral efficiency features. However, some challenges need to be addressed to realize this technology in practice. One of the…

Signal Processing · Electrical Eng. & Systems 2020-10-21 Mehmet Ali Aygul , Mahmoud Nazzal , Huseyin Arslan

Reconfigurable intelligent surfaces (RISs) are arrays of passive elements that can control the reflection of the incident electromagnetic waves. While RIS are particularly useful to avoid blockages, the protocol aspects for their…

Information Theory · Computer Science 2026-03-16 Victor Croisfelt , Fabio Saggese , Israel Leyva-Mayorga , Radoslaw Kotaba , Gabriele Gradoni , Petar Popovski

Intelligent reflecting surface (IRS) that enables the control of wireless propagation environment has recently emerged as a promising cost-effective technology for boosting the spectrum and energy efficiency in future wireless communication…

Information Theory · Computer Science 2020-02-25 Samith Abeywickrama , Rui Zhang , Qingqing Wu , Chau Yuen

In this letter, we consider a double-active-intelligent reflecting surface (IRS) aided wireless communication system, where two active IRSs are properly deployed to assist the communication from a base station (BS) to multiple users located…

Information Theory · Computer Science 2023-07-25 Zhenyu Kang , Changsheng You , Rui Zhang