Fronthaul Compression and Beamforming Optimization for Secure Cell-free ISAC Systems

TL;DR

This paper develops a joint optimization framework for fronthaul compression and beamforming in secure cell-free ISAC systems, enhancing sensing and communication security under limited fronthaul capacity.

Contribution

It introduces a novel joint design approach considering fronthaul constraints and secrecy requirements, solved via minorization-maximization and semidefinite programming.

Findings

Proposed algorithm outperforms distributed sensing and random beamforming schemes.

Enhanced sensing performance with secure communication in cell-free MIMO systems.

Effective handling of fronthaul capacity limitations and secrecy constraints.

Abstract

This letter aims to provide sensing capabilities for a potential eavesdropper, while simultaneously enabling the secure communications with the legitimate users in a cell-free multipleinput multiple-output system with limited fronthaul links. In order to maximize the sensing performance, the joint design of fronthaul compression and beamforming is proposed considering the constraints on the finite fronthaul-capacity links and the maximum power along with the worst-case secrecy rate requirements. To this end, we propose an algorithmic solution based on the minorization-maximization method and semidefinite programming relaxation techniques, whose performance superiority is verified via simulations compared to the reference schemes such as distributed sensing and random beamforming.