Coexistence of Radar and Communication with Rate-Splitting Wireless Access

TL;DR

This paper introduces a rate-splitting approach for uplink integrated sensing and communication, improving the trade-off between radar sensing and data transmission performance in wireless networks.

Contribution

It is the first to apply a rate-splitting strategy as a general framework for non-orthogonal coexistence of sensing and communication functions.

Findings

Achieves better sensing-communication trade-off than OMA and NOMA.

Derives optimal power split for maximizing communication performance.

Provides inner bounds on ergodic data and radar estimation rates.

Abstract

Future wireless networks are envisioned to facilitate the seamless coexistence of communication and sensing functionalities, thereby enabling the much-touted integrated sensing and communication (ISAC) paradigm. A key challenge in ISAC is managing inter-functionality interference while maintaining a balanced performance trade-off. In this work, we propose a rate-splitting (RS)-inspired approach to address this challenge in an uplink ISAC scenario, where a base station (BS) serves an uplink communication user while detecting a radar target. We derive inner bounds on the ergodic data information rate for the communication user and the ergodic radar estimation information rate for the sensing target. A closed-form solution is also derived for the optimal power split in RS that maximizes the communication user's performance. Compared to orthogonal multiple access (OMA)- and non-orthogonal multiple access (NOMA)-inspired approaches, the proposed approach achieves a more favorable sensing-communication trade-off by virtue of the decoding order flexibility introduced through splitting the communication message. Notably, this is the first work to employ an RS-inspired strategy as a general framework for non-orthogonal coexistence of sensing and communication, extending its applicability beyond traditional digital-only settings.