Fundamental Limits of Communication-Assisted Sensing in ISAC Systems

TL;DR

This paper introduces a communication-assisted sensing framework in ISAC systems, analyzing its fundamental limits and demonstrating how coordination can improve sensing quality beyond traditional methods.

Contribution

It develops an information-theoretic framework for CAS in ISAC, characterizes the limits of sensing quality, and demonstrates potential enhancements through a case study.

Findings

Achieves a theoretical characterization of sensing distortion limits.

Shows potential for improved sensing performance via CAS.

Demonstrates distortion minimization in a practical ISAC scenario.

Abstract

In this paper, we introduce a novel communication-assisted sensing (CAS) framework that explores the potential coordination gains offered by the integrated sensing and communication technique. The CAS system endows users with beyond-line-of-the-sight sensing capabilities, supported by a dual-functional base station that enables simultaneous sensing and communication. To delve into the system's fundamental limits, we characterize the information-theoretic framework of the CAS system in terms of rate-distortion theory. We reveal the achievable overall distortion between the target's state and the reconstructions at the end-user, referred to as the sensing quality of service, within a special case where the distortion metric is separable for sensing and communication processes. As a case study, we employ a typical application to demonstrate distortion minimization under the ISAC signaling strategy, showcasing the potential of CAS in enhancing sensing capabilities.