UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Fluid Reconfigurable Intelligent Surfaces: Joint On-Off Selection and Beamforming With Discrete Phase Shifts

Xiao, Han; Hu, Xiaoyan; Wong, Kai-Kit; Hong, Hanjiang; Alexandropoulos, George C; Chae, Chan-Byoung; (2025) Fluid Reconfigurable Intelligent Surfaces: Joint On-Off Selection and Beamforming With Discrete Phase Shifts. IEEE Wireless Communications Letters 10.1109/LWC.2025.3587070. (In press). Green open access

[thumbnail of WCL2025-FluidRIS-v5.pdf]
Preview
Text
WCL2025-FluidRIS-v5.pdf - Accepted Version

Download (2MB) | Preview

Abstract

This letter proposes a fluid reconfigurable intelligent surface (FRIS) paradigm, extending the conventional reconfigurable intelligent surface (RIS) technology to incorporate position reconfigurability of the elements. In our model, a ‘fluid’ element is realized by a dense matrix of subelements over a given space and dynamically selecting specific elements for signal modulation based on channel conditions. Specifically, we consider a FRIS-assisted single-user single-input single-output (SU-SISO) system and formulate an optimization problem that can jointly optimize element selection and their discrete phase shifts to maximize the achievable rate. To address this problem efficiently, we propose an iterative algorithm based on the cross-entropy optimization (CEO) framework. Simulation results reveal that FRIS achieves significant performance gains over traditional RIS.

Type: Article
Title: Fluid Reconfigurable Intelligent Surfaces: Joint On-Off Selection and Beamforming With Discrete Phase Shifts
Open access status: An open access version is available from UCL Discovery
DOI: 10.1109/LWC.2025.3587070
Publisher version: https://doi.org/10.1109/lwc.2025.3587070
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Fluid antenna system (FAS), fluid reconfigurable intelligent surface (FRIS), position optimization, discrete phaseshift, cross-entropy optimization (CEO)
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng
URI: https://discovery.ucl.ac.uk/id/eprint/10212704
Downloads since deposit
5Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item