Design of Wireless Time Synchronization System in Intelligent Transportation

Along with the development of science and technology, autonomous vehicles have gradually entered people's lives. The roadside monitoring system, autonomous vehicles and cloud control and command center will form a great intelligent transportation network. High precision time synchronization between various network nodes is the foundation for the stable and secure operation of the intelligent transportation network. At present, NTP and PTP network time synchronization methods are mostly used in the transportation networks with the accuracy in the magnitude of several microseconds. If the further development of intelligent transportation and some special application are taken into account, the higher time synchronization accuracy will required. A high precision time synchronization system for intelligent transportation is designed based on the principles of pseudo-random code ranging, two-way time comparison, and CDMA (code division multiple access) technology. And the experimental platforms are also built to verify the designed time synchronization system. The zero baseline experiment results show that the time synchronization accuracy better than 1 ns is reached. The time synchronization accuracy of ten nanoseconds can be achieved when the time synchronization equipment located in a running car, and the maximum speed of the car is 100km/h. The experiment results meet the application requirements of time synchronization between autonomous vehicles and roadside systems in intelligent transportation.