Depth spread spectrum low orbit satellite carrier synchronization method and system in high dynamic scene

Abstract

The invention discloses a deep spread spectrum low orbit satellite carrier synchronization method and system in a high dynamic scene. The method comprises the following steps: S1, performing matched filtering on down-conversion data; S2, acquiring an initial position, a frequency offset value and a frequency offset change rate of the filtering data, and performing coarse compensation on the filtering data; S3, de-spreading the coarse compensation data; setting a frequency offset step value and a frequency offset change rate step value; S4, performing Doppler frequency compensation on the de-spread data by using the frequency offset value and the frequency offset change rate, and performing phase compensation on the secondary compensation data by using phase estimation to obtain tertiary compensation data; S5, performing phase tracking on the tertiary compensation data through a phase-locked loop to obtain fine compensation data; and S6, performing CRC verification on the fine compensation data, if verification fails, updating the frequency offset value and the frequency offset change rate, and returning to S4 and S5. Frequency offset coarse compensation is achieved in the capturing stage, the signal frequency offset is reduced to be within 1 Hz in the frequency sweeping stage, frequency offset compensation within 1 Hz is achieved in the tracking stage, and carrier signal fine synchronization is achieved.

Description

technical field [0001] The invention relates to the technical field of low-orbit satellite signal carrier synchronization, in particular to a method and system for deep-spreading low-orbit satellite carrier synchronization in a high-dynamic scene. Background technique [0002] Due to many advantages such as high function density, low cost, and small size, low-orbit satellites have attracted more and more attention from people, and have broad application prospects in aerospace, communication emergency, measurement and control, and other fields. At present, low-orbit satellites are constantly developing towards networking and constellations. As an important guarantee for military communication informatization, the low-orbit satellite network composed of inter-satellite links can provide support for global data communication and is an important part of the global satellite communication system. [0003] The dynamic characteristics of the communication link between the low-orbi...

AI Technical Summary

Problems solved by technology

[0008] The technical solution above: provides a carrier synchronization method for low-orbit satellites in a high-dynamic environment with deep spread spectrum, which can effectively solve the problem in low-orbit satellite communications for low-orbit satellites that are extremely sensitive to channels with large frequency offsets and their rate of change. Carrier synchronization problem under the condition of small bandwidth of burst signal after despreading, Doppler frequency shift and change rate, frequency offset estimation and frequency offset change rate estimation are inaccurate

Images