Secure ISAC MIMO systems: exploiting interference with Bayesian Cramér-Rao bound optimization

Area of Science:

• Electrical Engineering
• Information Theory
• Signal Processing

Background:

• Integrated Sensing and Communication (ISAC) systems offer dual functionality but face security challenges.
• Potential eavesdroppers can exploit communication signals for surveillance.
• Optimizing sensing performance while ensuring communication security is crucial for ISAC.

Purpose of the Study:

• To develop a signaling design for secure ISAC systems.
• To optimize target sensing performance while maintaining communication quality of service.
• To enhance the physical layer security of ISAC systems against eavesdropping.

Main Methods:

• Utilizing a dual-functional MIMO base station for simultaneous communication and sensing.
• Minimizing the Bayesian Cramér-Rao bound for sensing performance optimization.
• Exploiting constructive interference to create destructive signal regions for eavesdroppers.
• Employing a successive convex approximation method to solve the non-convex optimization problem.

Main Results:

• The proposed signaling design effectively enhances the physical layer security of ISAC systems.
• The method successfully optimizes sensing performance by minimizing the Bayesian Cramér-Rao bound.
• Numerical results demonstrate superior performance compared to traditional block-level precoding techniques.
• Constructive interference is strategically used to degrade eavesdropper decoding probability.

Conclusions:

• The developed secure ISAC signaling design is effective in simultaneously achieving sensing optimization and communication security.
• The proposed successive convex approximation method provides an efficient solution for the complex optimization problem.
• This work significantly advances the physical layer security capabilities of ISAC systems.