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

• Published in: IEEE communications letters Vol. 26; no. 10; pp. 2237 - 2241
• Main Authors: Yin, Longfei, Mao, Yijie, Dizdar, Onur, Clerckx, Bruno
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 6G mobile communication; Estimation; integrated sensing and communications (ISAC); Measurement; Moving targets; Multiple access; next generation multiple access~(NGMA); Radar; Radar cross-sections; Rate-splitting multiple access (RSMA); Sensors; Spaceborne radar; Splitting; Waveforms
• DOI: 10.1109/LCOMM.2022.3192032
• ISSN: 1089-7798

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 RSMA-assisted 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 Cramér-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 verified 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.