Research On Signal Synchronization Of Low Signal - To - Noise Ratio In Satellite

Inter-satellite communications link refers to the communication link established between the satellite. Terrestrial microwave relay stations "double jump" work which may be substituted by using such a link structure, and dependence on terrestrial repeater stations can be reduced a lot. This inter-satellite link structure consists of many satellites, communication between satellites via the composition of satellite network, users can access multiple satellites when they need, which not only ensures the real-time information, but also ensures the safety and reliability which many satellites bring. Inter-satellite communication links can be used for the data relay satellite, which not only solves the problem of the high coverage and control of communications, but also solves the high-speed data transmission,multi-objective measurement and control communications, and some other technical problems.Inter-satellite communication is an important technology to the communication between the satellite and the satellite. Communication on Satellite communication channel can be affected by noise and other interference. To achieve reliable communication between stars under the limitation of star power and bandwidth resources,can use reliable inter-satellite communication technology, while synchronous satellite communication technology is a very important part of reliable communication.In this paper, for the needs of the project,doing the following studies for inter-satellite link low SNR signal synchronization technology:signal designing; obtaining obtained preferred combination code sequence by truncation of m sequences and M sequence combinations; commonly capture algorithms comparing; designing the capture structure which can get the carrier frequency and code phase simultaneously for the preferred combinations code sequences; new performance capture structural analysis; phase-locked loop principles and parameters designing; the principle of pseudo-code synchronization and the techniques of interpolation;the parameter analysis, simulation and performance analysis for the interpolation segmented parabolic Farrow structure; the design and the phase and frequency discriminator method for the carrier loop structure;the structure design,implementation and performance analysis for the third-order phase-locked loop assisted with the separated second-order frequency-locked loop.