Method for rapidly capturing burst signals of satellite internet of things

Abstract

The invention discloses a method for rapidly capturing a burst signal of a satellite internet of things. The calculation of a ground terminal is increased, the on-satellite load calculation amount is reduced, the Doppler frequency shift is compressed from + / -8-12KHz to below + / -3KHz, the frequency uncertainty of on-satellite demodulation information is reduced, the influence of the Doppler frequency shift on the capturing performance of a short-time burst spread spectrum signal is eliminated, and the capturing time is shortened. The satellite broadcasts own ephemeris and ephemeris of other satellites in the whole network; the ground terminal determines its own position when accessing the network for the first time, acquires its own position in real time, corrects local time and time precision according to navigation data, attempts to capture satellite broadcast frames after startup, acquires a current satellite ephemeris after capturing the satellite broadcast frames, calculates the satellite position, the relative distance and the relative speed at the subsequent time according to the satellite ephemeris, calculates an optimal transmitting moment and a used spreading code, calculates the time delay and the satellite-ground Doppler frequency shift of the optimal transmitting moment, calculates a real emission moment, and when the real transmitting moment is reached, enables the terminal to reversely preset frequency offset and bursts data.

Description

technical field [0001] The invention relates to the field of satellite internet of things, in particular to a method for realizing rapid capture of satellite internet of things burst signals. Background technique [0002] In recent years, the gradual rise of the Internet of Things has greatly changed people's lifestyles. Smart homes, environmental monitoring, and smart cities are almost everywhere. However, the ground Internet of Things is limited by the coverage area of ​​ground base stations and cannot achieve global coverage. Due to its wide coverage and unrestricted by geographical and climatic factors, satellite communication can provide global quasi-real-time short data transmission services and realize the true "Internet of Everything" on a global scale. [0003] The communication frequency of the satellite Internet of Things mainly works in the VHF frequency band (30MHz~300MHz, wavelength 1m~10m) and UHF frequency band (300MHz~3GHz, wavelength 1m~0.1m), but the VHF f...

AI Technical Summary

Problems solved by technology

Therefore, the uplink and downlink frequency bands are extremely susceptible to interference, and even ordinary radio amateurs may cause interference to the communication of the satellite Internet of Things

Among them, relatively speaking, the uplink of satellite communication is relatively fragile

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