Doppler frequency offset processing method between low-orbit satellite and ground terminal

Abstract

The invention discloses a Doppler frequency offset processing method between a low-orbit satellite and a ground terminal; the processing method comprises the steps that an upper computer calculates the time origin; step 2, a servo sub-machine feeds back the accurate time information of the starting time of a successful satellite to the upper computer; step 3, the upper computer calculates relevantinitialization parameters; step 4, the upper computer transmits relevant initialization parameters to a DSP, and the DSP transmits the quantized parameter information to an FPGA; step 5, the FPGA performs quantitative calculation of Doppler frequency offset according to the initialization parameter information transmitted by the DSP, and a transceiver carries out separate calculation according todifferent carrier frequencies; and step 6, according to the calculated Doppler frequency offset estimation value, pre-distortion is carried out on an emission sub-machine, and post-compensation is carried out on a receiving sub-machine. According to the method, the stable carrier synchronization is realized; the difficulty of satellite decoding is reduced; the hardware implementation difficulty of Doppler frequency offset calculation is simplified, so that complex algorithm design in the FPGA is avoided; and the pre-distortion and compensation conditions of the bottom-layer Doppler frequencyoffset are monitored in real time.

Description

technical field [0001] The invention belongs to the field of low-orbit satellite communication, and proposes a Doppler frequency offset processing method between a low-orbit satellite and a ground terminal, and provides its realization method in FPGA. Background technique [0002] With the introduction of concepts such as satellite Internet, commercial aerospace, and 5G+ satellite network, low-orbit satellite network communication and gradually transitioning to a higher Ka frequency band have become an important development direction of satellite communication. Compared with geostationary satellites, low-orbit satellite network communication mainly has the following characteristics: 1) There is a visible time between a single satellite and a certain terminal, and the two parties can only communicate within the visible time period; 2) There is a high-speed relative motion between the satellite and the terminal, and the communication frequency band is getting higher and higher...

AI Technical Summary

Problems solved by technology

However, the above processing methods cannot be well adapted to the characteristics of large and rapid changes in Doppler frequency offset in low-orbit satellite communications.

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