RSMA Assisted ISAC With Hybrid Beamforming

TL;DR

This paper proposes a hybrid beamforming assisted mmWave ISAC system enhanced with RSMA to improve emergency wireless communications, addressing interference issues and optimizing resource allocation through advanced algorithms.

Contribution

It introduces a novel RSMA-assisted HBF design for mmWave ISAC systems, jointly optimizing rate allocation and beamforming to enhance performance in resource-constrained environments.

Findings

RSMA improves interference management in HBF ISAC systems.

The proposed algorithm outperforms benchmark schemes in simulations.

Joint optimization significantly enhances weighted sum rate.

Abstract

The harsh environment and scarce resources post-disaster drive the equipment to be miniaturized and portable. Based on this, integrated sensing and communication (ISAC) systems play a significant role in providing emergency wireless networks. In order to reduce the hardware cost, a hybrid beamforming (HBF) assisted millimeter-wave (mmWave) ISAC system, which exploits the limited number of radio frequency (RF) chains, is considered in this paper. However, the HBF structure reduces the spatial degrees of freedom, thus leading to increased interference among communication users and radar sensing. To solve this problem, a rate-splitting multiple access (RSMA) strategy is adopted to enhance the emergency mmWave-ISAC system. We formulate the weighted sum rate (WSR) maximization objective by jointly designing common rate allocation and HBF. Then, we propose the penalty dual decomposition (PDD) coupled with the weighted mean squared error (WMMSE) method to solve this high-dimensional non-convex problem. Numerical results demonstrate the effectiveness of the proposed algorithm and show that the RSMA-ISAC scheme outperforms other benchmark schemes.