A crystal oscillator frequency offset determination method, device and communication system

Abstract

Embodiments of the present invention provide a crystal oscillator frequency offset determination method, device and communication system, wherein a satellite sends a synchronization signal block carrying a first synchronization sequence to a terminal. The terminal calculates the carrier frequency offset of the synchronization signal block based on the first synchronization sequence, the second synchronization sequence, and the frequency offset estimation algorithm; performs frequency offset pre-compensation on the transmission frequency based on the carrier frequency offset to obtain the first transmission frequency; according to the first transmission frequency Send carrier frequency offset to satellite. The satellite calculates the crystal oscillator frequency offset of the terminal based on the carrier frequency offset and the receiving frequency of the satellite, and sends the crystal oscillator frequency offset to the gateway station. The gateway station sends a random access response signal carrying a crystal oscillator frequency offset to the satellite. The satellite forwards the random access response signal to the terminal. The terminal acquires the crystal oscillator frequency offset carried in the random access response signal. Based on the above processing, the crystal oscillator frequency offset can also be determined without a temperature sensor, and further, the terminal can perform frequency offset pre-compensation based on the crystal oscillator frequency offset, which can improve the accuracy of the terminal frequency offset pre-compensation.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a crystal oscillator frequency offset determination method, a device and a communication system. Background technology [0002] In the satellite communication system, due to the high-speed movement of the satellite, the signal sent by the satellite to the terminal will produce Doppler frequency offset. In addition, the carrier wave when the terminal sends and receives signals is generated by the crystal oscillator inside the terminal. Due to the influence of environmental temperature, voltage, noise and other factors, there will be a frequency deviation between the actual frequency of the carrier generated by the crystal oscillator and the preset nominal frequency, which is the crystal oscillator frequency deviation of the terminal. [0003] In the prior art, technicians can measure the actual frequency of the carrier wave generated by the crystal oscillator under different amb...

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Problems solved by technology

[0004] However, when measuring the frequency deviation of the crystal oscillator under different ambient temperatures, the number of ambient temperatures to be set is limited, that is, the corresponding relationship between the ambient temperature recorded in the terminal and the frequency deviation of the crystal oscillator is limited. If there is no current ambient temperature, the corresponding crystal oscillator frequency deviation cannot be determined

In addition, if the terminal is not equipped with a temperature sensor, the current ambient temperature cannot be determined, and the crystal oscillator frequency offset corresponding to the current ambient temperature cannot be determined.

At this time, the terminal can only perform frequency offset pre-compensation based on the Doppler frequency offset of the received signal, resulting in low accuracy of terminal frequency offset pre-compensation

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