Integrated Time-frequency Data Transmission Base On WR

With the progress and development of communication and information science,the synchronization accuracy of the existing Network Time Protocol(NTP)is at the millisecond level,while the Precision Time Synchronization Protocol(PTP)can only reach submicroseconds at the highest.level of time accuracy.But new application scenarios such as the Internet of Things or next-generation 5G mobile communication networks require higher time synchronization accuracy and highly scalable synchronization protocols as well as higher transmission rates.This dissertation mainly studies two parts.One is to study the dual-port clock synchronization and distribution.The second is to study the data transmission of Gigabit Ethernet,and in the implementation process,the custom TCP/IP encapsulation logic needs to be compatible with the White Rabbit standard.In order to improve the transmission quality and reduce the production cost,the clock and data are fused together for Gigabit Ethernet fiber transmission.The main work done in this paper is as follows:1.Clarify the theory and realization principle of White Rabbit.It mainly includes White Rabbit clock synchronization algorithm,Synchronous Ethernet(Sync),Full Digital Dual Mixing Phase Detector(DDMTD),link delay asymmetry calculation and compensation technology,etc.,and analyzes the impact of White Rabbit key technologies on the performance of clock systems.2.Research the design scheme of clock interface and data transmission.First,the realization and advantages of high-precision dual-port node clock and the technology of high-precision clock phase adjustment are studied;and the clock modules of dual-port nodes can be cascaded to form a multi-node chain topology.Second,the research on the high-speed data transmission method based on the TCP/IP protocol of Microblaze embedded system;finally,the data and clock information are integrated and transmitted based on Gigabit Ethernet fiber.3.The realization of the specific hardware circuit of the dual-port clock data module.The selection,design and logic function of the hardware circuit in the clock interface and data transmission are described in detail.4.Using the developed dual-port clock data module,the corresponding performance tests are carried out on the clock interface and data transmission.Build an experimental test platform for time distribution to test the synchronization accuracy of multi-node time distribution.In the optical fiber link,experiments show that the point-to-point time synchronization deviation is 232.8ps,the time synchronization accuracy is 42.3ps,the cascaded time synchronization deviation is-421.3ps,and the time synchronization accuracy is 53.7ps.In terms of data testing,the data rate test results of the short-term test results and the long-term test results both reached about 190 Mbps.