RIS-Aided Integrated Sensing and Communication: Joint Beamforming and Reflection Design

TL;DR

This paper explores the use of reconfigurable intelligent surfaces (RIS) in integrated sensing and communication systems to enhance target detection and communication performance through joint beamforming and reflection optimization.

Contribution

It introduces a novel joint optimization framework for RIS-assisted ISAC systems, combining multiple optimization techniques to improve detection and communication performance.

Findings

RIS deployment significantly improves ISAC system performance

The proposed algorithm effectively optimizes beamforming and reflection coefficients

Simulation results confirm the advantages of RIS in ISAC applications

Abstract

Integrated sensing and communication (ISAC) has been envisioned as a promising technique to alleviate the spectrum congestion problem. Inspired by the applications of reconfigurable intelligent surface (RIS) in dynamically manipulating wireless propagation environment, in this paper, we investigate to deploy a RIS in an ISAC system to pursue performance improvement. Particularly, we consider a RIS-assisted ISAC system where a multi-antenna base station (BS) performs multi-target detection and multi-user communication with the assistance of a RIS. Our goal is maximizing the weighted summation of target detection signal-to-noise ratios (SNRs) by jointly optimizing the transmit beamforming and the RIS reflection coefficients, while satisfying the communication quality-of-service (QoS) requirement, the total transmit power budget, and the restriction of RIS phase-shift. An efficient alternating optimization algorithm combining the majorization-minimization (MM), penalty-based, and manifold optimization methods is developed to solve the resulting complicated non-convex optimization problem. Simulation results illustrate the advantages of deploying RIS in ISAC systems and the effectiveness of our proposed algorithm.