Communication Security and Sensing Privacy in FMCW-Based ISAC Through Signal Modulation

2026-05-22

AI Summary

This work addresses the dual challenges of insufficient communication security and vulnerable sensing privacy in integrated sensing and communication (ISAC) systems by proposing a novel signal modulation architecture tailored for frequency-modulated continuous-wave (FMCW) radar. The approach uniquely integrates index modulation (IM) with a purpose-designed phase coding (PC) scheme to simultaneously enhance physical-layer security and sensing privacy. Specifically, IM strengthens communication confidentiality, while the customized phase coding deliberately distorts the radar ambiguity function, thereby impeding unauthorized receivers from accurately estimating target range and velocity. Simulation results demonstrate that the proposed method significantly improves both communication security and sensing privacy protection without compromising high data throughput.

Abstract

This study proposes a novel radar-centric signaling design and architecture for secure integrated sensing and communication (ISAC) systems. The proposed framework is designed to provide robust physical layer security for data transmission while simultaneously enhancing sensing privacy. It employs index modulation and phase coding over frequency-modulated continuous-wave radar (FMCW) chirps, where index modulation (IM) provides an outer layer of data security, and we explicitly design the phase coding (PC) to perturb the resulting signal's ambiguity function (AF) to enhance sensing privacy. This design reduces the risk of unauthorized surveillance by rendering target velocity estimation practically infeasible for unauthorized passive sensing hardware (i.e., a sensing eavesdropper, S-Eve) and significantly impairing its range estimation capabilities. Furthermore, this study also presents the transmitter and receiver architectures required for effective modulation and demodulation of the proposed ISAC signaling and for performing sensing at the legitimate sensing hardware. Simulation results show that the proposed approach achieves high data throughput while enhancing communication security and sensing privacy.

Problem

• Integrated Sensing and Communication
• Physical Layer Security
• Sensing Privacy
• FMCW Radar
• Ambiguity Function

Innovation

• Index Modulation
• Phase Coding
• Ambiguity Function
• Integrated Sensing and Communication
• Physical Layer Security