Covert Communication Scheme for OOK in Asymmetric Noise Systems

Area of Science:

• Information Theory
• Communications Engineering
• Signal Processing

Background:

• Existing covert communication schemes using On-Off Keying (OOK) are limited by their inability to handle asymmetric noise environments.
• This limitation restricts their application in advanced scenarios like terahertz and underwater acoustic covert communications.

Purpose of the Study:

• To propose a novel phase-based OOK coding scheme designed for covert communications in asymmetric noise conditions.
• To enhance the performance of covert transmissions by exploiting noise characteristics for better masking.

Main Methods:

• A phase-based OOK coding scheme is proposed, allowing transmitter phase adjustment to align with stronger noise components.
• Kullback-Leibler (KL) divergence and mutual information are used to quantify covertness and transmission performance.
• An optimization problem is formulated and solved to maximize the covert transmission rate by adjusting signal distribution, amplitude, and initial phase.

Main Results:

• The initial phase angle and Gaussian noise components significantly impact both covertness and transmission rates in asymmetric noise systems.
• Optimizing the initial phase to align with lower noise directions effectively suppresses interference.
• The proposed scheme demonstrates improved covertness and transmission performance in asymmetric noise environments.

Conclusions:

• The phase-based OOK coding scheme offers a viable solution for covert communications in challenging asymmetric noise scenarios.
• Strategic adjustment of the initial phase is crucial for maximizing covertness and data rates.
• This research advances covert communication capabilities in complex environments like terahertz and underwater acoustics.