Joint Secure Transmit Beamforming Designs for Integrated Sensing and Communication Systems

TL;DR

This paper proposes joint beamforming strategies for integrated sensing and communication systems to enhance physical layer security by exploiting radar interference and artificial noise, ensuring secure and reliable multi-user communication and radar detection.

Contribution

It introduces novel joint transmit beamforming schemes that leverage radar interference and artificial noise to improve security in ISAC systems, considering both known and unknown eavesdropper CSI.

Findings

Proposed beamforming reduces eavesdropper SINR effectively.

Joint design guarantees QoS for legitimate users and radar performance.

Simulations confirm improved security and system robustness.

Abstract

Integrated sensing and communication (ISAC), which allows individual radar and communication systems to share the same spectrum bands, is an emerging and promising technique for alleviating spectrum congestion problems. In this paper, we investigate how to exploit the inherent interference from strong radar signals to ensure the physical layer security (PLS) for the considered multi-user multi-input single-output (MU-MISO) communication and colocated multi-input multi-output (MIMO) radar coexistence system. In particular, with known eavesdroppers' channel state information (CSI), we propose to jointly design the transmit beamformers of communication and radar systems to minimize the maximum eavesdropping signal-to-interference-plus-noise ratio (SINR) on multiple legitimate users, while guaranteeing the communication quality-of-service (QoS) of legitimate transmissions, the requirement of radar detection performance, and the transmit power constraints of both radar and communication systems. When eavesdroppers' CSI is unavailable, we develop a joint artificial noise (AN)-aided transmit beamforming design scheme, which utilizes residual available power to generate AN for disrupting malicious receptions as well as satisfying the requirements of both legitimate transmissions and radar target detection. Extensive simulations verify the advantages of the proposed joint beamforming designs for ISAC systems on secure transmissions and the effectiveness of the developed algorithms.