Research on High-Speed Clock Synchronization Technology for Inter-satellite Coherent Laser Communication Link

In order to solve the interstellar high-rate transmission problem in satellite Internet and guarantee the rapid construction of space-based broadband information network, this paper focuses on the research of high-speed clock synchronization technology for interstellar coherent laser communication. We achieved clock synchronization of 100 Gbps high-speed signals by optimizing the Gardner feedback all-digital clock synchronization algorithm, which based on the PM-QPSK heterodyne digital coherent system. The traditional clock synchronization algorithm is difficult to meet the high precision synchronization demand of 100G rate laser communication. The clock synchronization algorithm described in this paper has the characteristics of high speed, full digital and full feedback. In addition, a high-speed clock synchronization technology verification test was built in the indoor equivalent verification environment of the inter-satellite laser communication terminal. The 100 Gbps high-speed coherent laser communication is realized, and the bit error rate is better than 1E-7. The effectiveness of the high-speed clock synchronization algorithm is verified, which is of great significance to the development of high-speed coherent laser communication between satellites.