Fundamental Limits of Multiple-Access Integrated Sensing and Communication Systems

TL;DR

This paper investigates the fundamental limits of integrated sensing and communication in a multiple access channel, deriving improved bounds for capacity and sensing accuracy through novel cooperative schemes.

Contribution

It introduces new inner and outer bounds for the capacity-distortion region in a state-dependent multiple access channel with integrated sensing and communication.

Findings

Proposed bounds outperform existing bounds.

Numerical examples demonstrate strict improvements.

Unified cooperative communication and sensing scheme.

Abstract

A state-dependent discrete memoryless multiple access channel is considered to model an integrated sensing and communication system, where two transmitters wish to convey messages to a receiver while simultaneously estimating the state parameter sequences through echo signals. In particular, the sensing state parameters are assumed to be correlated with the channel state. In this setup, improved inner and outer bounds for capacity-distortion region are derived. The inner bound is based on an achievable scheme that combines message cooperation and joint compression of past transmitted codewords and echo signals at each transmitter, resulting in unified cooperative communication and sensing. The outer bound is based on the ideas of dependence balance for communication rate, genie-aided state estimator and rate-limited constraints on sensing distortion. The proposed inner and outer bounds are proved to improve the state-of-the-art bounds. Finally, numerical examples are provided to demonstrate that our new inner and outer bounds strictly improve the existing results.