Low earth orbit satellite communication dynamic time delay and Doppler simulation method

Abstract

The invention discloses a low earth orbit satellite communication dynamic time delay and Doppler simulation method, which calculates dynamic transmission time delay and dynamic Doppler frequency offset according to a real-time communication distance between a low earth orbit satellite and a ground terminal, and designs a corresponding dynamic time delay simulation system according to a low earth orbit satellite signal transmission model. A sending signal of a satellite end can be simulated to obtain a ground receiving signal in a real-time dynamic time delay scene after passing through the dynamic time delay simulation system. According to the dynamic time delay simulation system, the dynamic time delay filter does not need to calculate the filter coefficient in real time, the filter coefficient can be updated only by inputting the real-time time delay through the Farrow structure, and compared with other schemes, the dynamic time delay simulation system is simple in structure, low inimplementation complexity and accurate in simulation result. Meanwhile, up-sampling and down-sampling processing is adopted to enable a satellite sending signal frequency band to be in a working frequency band with good amplitude-frequency response of a time delay filter, and errors of a time delay simulation system are further reduced.

Description

technical field [0001] The invention belongs to the communication field, and in particular relates to a dynamic time delay and Doppler simulation method for low-orbit satellite communication realized by using a fractional time delay filter. Background technique [0002] Low-orbit satellites operate at an orbital altitude of about 600km to 1500km, and their orbital period around the earth is less than 24 hours. Therefore, low-orbit satellites cannot remain relatively stationary with the ground receiving end like geostationary orbit satellites, but there is relative motion with the ground receiving end. The period during which the low-orbit satellite passes above the ground receiver and communicates with the ground receiver is called the overhead process of the low-orbit satellite. Due to the relative motion of the low-orbit satellite and the ground receiving end during the overhead process, the communication distance between the ground receiving end and the ground receiving ...

AI Technical Summary

Problems solved by technology

At the same time, the communication in the relative motion process will also cause Doppler frequency deviation, and the corresponding Doppler frequency deviation at different times is also constantly changing, making it difficult to accurately simulate the actual received signal of the ground terminal

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