Joint Time Synchronization and Ranging Method Aided by Doppler Frequency Shift

Radio-based two-way message exchange is an important time synchronization method. However, the accuracy of synchronization and ranging decreases when the clock is not ideal. In this study, we considered a time-varying accumulated clock offset, and proposed a Doppler-shift assisted joint time synchronization and ranging method based on Extended Kalman Filter (EKF). The accumulated clock offset and local Doppler shift were modeled; time stamps and Doppler shift information were exchanged during synchronization; the joint estimation of clock and distance parameters were accomplished through the EKF. Simulation experiments showed that the proposed method can further improve the synchronization and ranging accuracy as well as reduce the convergence time compared with the recently proposed extended time-varying Kalman filter method.