A Novel Method Based on Kalman Filter for Phase Noise Rejection in Two-Way Optic-Fiber Time Transfer System

Optic-fiber time transfer is the main method for long-distance high-precision time synchronization, and is the supporting technology of national ground time synchronization system. To overcome the degradation of phase noise induced by long-distance optical fiber, optic relay amplifier and local frequency references in two-way optic-fiber time transfer based on spread spectrum, and to improve the accuracy of carrier phase measurement and time synchronization, the characteristic of phase noise in optic-fiber time transfer is analyzed. The high-precision carrier tracking model is proposed based on kalman filter and the joint optimization is analyzed in the presence of white noise and phase noise. This model has good performance on tracking carrier phase at the transmitting end, and improving carrier measurement accuracy. In all, it is useful for phase noise rejection and improving the accuracy and stability of time synchronization in long-distance high-precision time transfer.