An Auto Loss Compensation System for Capacitive-Coupled Body Channel Communication

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Signal Processing

Background:

• Capacitive-coupled body channel communication (CC-BCC) faces challenges with time-variant path loss, particularly due to backward coupling effects.
• Dynamic changes in channel characteristics, common in wearable and motion scenarios, degrade communication quality.

Purpose of the Study:

• To propose and validate an auto loss compensation (ALC) system for CC-BCC.
• To address and mitigate the impact of time-variant path loss in CC-BCC systems.
• To enhance the robustness and reliability of CC-BCC, especially in dynamic environments.

Main Methods:

• Development of an auto loss compensation (ALC) system utilizing a time-division gradient indicator.
• Implementation of a proportional integral (PI) controller for dynamic adjustment of a compensation inductor.
• Utilizing a closed-loop topology for continuous monitoring and real-time compensation.

Main Results:

• The proposed ALC system effectively compensates for path loss induced by backward coupling without requiring calibration.
• The system demonstrates dynamic attenuation of path loss, adapting to time-varying channel characteristics.
• Significant reduction in backward path loss was observed in simulations and experiments, particularly in wearable and motion scenarios.

Conclusions:

• The developed ALC system offers a robust solution for mitigating time-variant path loss in CC-BCC.
• The system's ability to dynamically adapt makes it suitable for real-world applications involving body channel communication.
• The findings highlight the potential of ALC systems to improve the performance of wearable and mobile CC-BCC applications.