Reliable Synchronization Technology for Continuous Variable Quantum Key Distribution System

Data synchronization is a critical technique for subsequent signal processing and secret key extraction of continuous variable quantum key distribution (CVQKD). In this paper, we propose a four-segment synchronization frame structure for CVQKD data synchronization at the first attempt. In order to verify the effectiveness of the structure, we build a data synchronization model containing device noise and fiber nonlinear noise. Simulation results indicate that the synchronization structure can effectively resist the influences of device electronic and fiber nonlinear noise, which is characterized by strong noise immunity, high reliability and easy implementation. The probability of bit synchronization and frame synchronization is 0.44 and 0.76 respectively when link distance is 50km.