Energy-Efficient Time Synchronization Based on Nonlinear Clock Skew Tracking for Underwater Acoustic Networks

Area of Science:

• Underwater Acoustic Networks (UANs)
• Sensor Networks
• Signal Processing

Background:

• Time synchronization (TS) is critical for scheduling and positioning in UANs.
• Existing TS algorithms struggle with energy efficiency, clock skew estimation, and impulsive noise.
• Challenges include dynamic clock skew and non-Gaussian noise in underwater environments.

Purpose of the Study:

• To propose an energy-efficient TS method for UANs.
• To accurately track time-varying clock skew in dynamic conditions.
• To suppress impulsive noise and improve synchronization accuracy.

Main Methods:

• Developed a nonlinear clock skew tracking (NCST) method.
• Utilized a receiver-only (RO) paradigm for energy efficiency.
• Employed Gaussian Mixture Model (GMM) for non-Gaussian noise and Particle Filter (PF) for state tracking.

Main Results:

• NCST-TS significantly reduces accumulative Root Mean Square Errors (RMSE) from 10^-4 s to 10^-5 s.
• The proposed method demonstrates superior energy efficiency compared to other TS algorithms.
• Effective suppression of impulsive noise and accurate tracking of clock skew dynamics were achieved.

Conclusions:

• The NCST-TS method offers a robust and energy-efficient solution for time synchronization in UANs.
• It effectively addresses challenges posed by nonlinear clock skew and non-Gaussian noise.
• This advancement is crucial for improving the performance of UANs in various applications.