A Secure Spatial Multiplexing Transmission Scheme in MIMO Amplify-and-Forward Wiretap Relaying Systems Using...

Area of Science:

• Wireless Communication
• Information Security
• Signal Processing

Background:

• Physical-layer security aims for low probability of interception (LPI) in wireless systems.
• Existing methods like beamforming and secrecy coding require eavesdropper channel knowledge, limiting practicality against passive eavesdropping.
• Artificial additive noise and artificial fast fading (AFF) offer LPI without channel state information, with AFF using random precoders to degrade eavesdropper detection.

Purpose of the Study:

• To propose a novel AFF design for spatial multiplexing multi-input multi-output (MIMO) amplify-and-forward (AF) relay systems.
• To enhance physical-layer security and low probability of interception (LPI) in wireless communications.
• To address the challenge of designing AFF schemes without requiring eavesdropper channel information.

Main Methods:

• Formulation of an optimization problem to minimize Bob's signal mean squared error (MMSE) while ensuring LPI.
• Application of a convex set approximation technique to handle the non-convex nature of the optimization problem.
• Derivation of a simple closed-form design for the AFF precoder.

Main Results:

• A novel closed-form AFF design for MIMO AF relay systems was successfully derived.
• The proposed design effectively balances the minimization of the legitimate receiver's (Bob) error with the maximization of the eavesdropper's (Eve) detection difficulty.
• Computer simulations validated the performance gains for both Bob and Eve, demonstrating the effectiveness of the proposed AFF scheme.

Conclusions:

• The developed AFF design provides an effective solution for enhancing physical-layer security in MIMO AF relay systems.
• The method achieves low probability of interception (LPI) without requiring knowledge of the eavesdropper's channel.
• The proposed approach offers a practical and efficient way to improve wireless communication security against eavesdropping.