Rate-Splitting Multiple Access for 6G -- Part II: Interplay with Integrated Sensing and Communications

TL;DR

This paper explores how rate-splitting multiple access (RSMA) can enhance integrated sensing and communications (ISAC) in 6G, demonstrating improved trade-offs between radar sensing and communication performance through simulation results.

Contribution

It introduces a general RSMA-assisted ISAC architecture and waveform design that jointly optimizes target estimation and user fairness, highlighting RSMA's advantages over traditional methods.

Findings

RSMA improves the communication-sensing trade-off in ISAC.

Simulation results confirm RSMA's superiority in terrestrial and satellite scenarios.

RSMA offers a promising approach for 6G and beyond networks.

Abstract

This letter is the second part of a three-part tutorial focusing on rate-splitting multiple access (RSMA) for 6G. As Part II of the tutorial, this letter addresses the interplay between RSMA and integrated radar sensing and communications (ISAC). In particular, we introduce a general RSMAassisted ISAC architecture, where the ISAC platform has a dual capability to simultaneously communicate with downlink users and probe detection signals to a moving target. Then, the metrics of radar sensing and communications are respectively introduced, followed by a RSMA-assisted ISAC waveform design example which jointly minimizes the Cramer-Rao bound (CRB) of target estimation and maximizes the minimum fairness rate (MFR) amongst communication users subject to the per-antenna power constraint. The superiority of RSMA-assisted ISAC is verifed through simulation results in both terrestrial and satellite scenarios. RSMA is demonstrated to be a powerful multiple access and interference management strategy for ISAC, and provides a better communication-sensing trade-off compared with the conventional benchmark strategies. Consequently, RSMA is a promising technology for next generation multiple access (NGMA) and future networks such as 6G and beyond.