RIS-Aided Integrated Sensing and Communication Systems under Dual-polarized Channels

2025-01-01

AI Summary

This work addresses the integrated sensing and communication (ISAC) system assisted by a reconfigurable intelligent surface (RIS) under dual-polarized channels. We jointly optimize the dual-polarized base station beamforming matrix and the dual-polarized RIS reflection coefficients to simultaneously enhance communication rate and sensing performance. To overcome the limitation of conventional ISAC frameworks that neglect polarization effects, we establish a novel dual-polarized electromagnetic channel model. We further propose a low-complexity beamforming algorithm based on a penalty function and an RIS reflection coefficient optimization method leveraging the majorization-minimization (MM) framework. Simulation results demonstrate that the proposed dual-polarized architecture achieves significantly higher achievable sum rates compared to single-polarized counterparts, validating the critical performance gain offered by polarization diversity in ISAC. This work establishes a new design paradigm for high-frequency, high-dimensional ISAC systems.

Technology Category

• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Novel mobile and WoT systems, and system-of-systems
• Security and Privacy: Security and privacy of machine learning and AI applications
• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG

Abstract

This paper considers reconfigurable intelligent surface (RIS)-aided integrated sensing and communication (ISAC) systems under dual-polarized (DP) channels. Unlike the existing ISAC systems, which ignored polarization of electromagnetic waves, this study adopts DP base station (BS) and DP RIS to serve users with a pair of DP antennas. The achievable sum rate is maximized through jointly optimizing the beamforming matrix at the DP BS, and the reflecting coefficients at the DP RIS. To address this problem, we first utilize the weighted minimum mean-square error (WMMSE) method to transform the objective function into a more tractable form, and then an alternating optimization (AO) method is employed to decouple the original problem into two subproblems. Due to the constant modulus constraint, the DP RIS reflection matrix optimization problem is addressed by the majorization-minimization (MM) method. For the DP beamforming matrix, we propose a penalty-based algorithm that can obtain a low-complexity closed-form solution. Simulation results validate the advantage of deploying DP transmit array and DP RIS in the considered ISAC systems.

Problem

• Bipolar Signal Environment
• Intelligent Surface Assisted Communication
• Performance Enhancement

Innovation

• Bipolar Signal Environment
• Reconfigurable Intelligent Surface
• Weighted Least Squares Error Optimization