Uplink frequency compensation method and device in satellite Internet of Things scene, and communication terminal

Abstract

The invention provides an uplink frequency compensation method and device in a satellite Internet of Things scene and a communication terminal, which are used for realizing consideration of three aspects of precision, signaling overhead and power consumption when frequency compensation is carried out for Doppler shift, so that the communication quality of the satellite Internet of Things is guaranteed. The method comprises the following steps: a communication terminal calculates a downlink signal Doppler frequency deviation value DDL of a communication link between the terminal and a satellite according to terminal position information of the communication terminal and ephemeris information sent by the satellite in a broadcast mode; the communication terminal calibrates clock information according to pulse per second of a clock module of the navigation receiver; the uplink crystal oscillator clock skew and the downlink crystal oscillator clock skew of the communication terminal are calculated according to the correlation between the uplink crystal oscillator clock skew and the downlink crystal oscillator clock skew; and the downlink crystal oscillator clock skew calculates the uplink crystal oscillator clock skew of the downlink crystal oscillator clock skew, and the communication terminal calculates the uplink signal frequency compensation value delta f compensation of the communication link according to the downlink signal Doppler frequency offset value DDL and the uplink crystal oscillator clock skew.

Description

technical field [0001] The present application relates to the field of information, in particular to an uplink frequency compensation method, device and communication terminal in a satellite Internet of Things scenario. Background technique [0002] As a powerful supplement to the Internet of Things, the satellite Internet of Things provides global users with low-cost, wide coverage, low latency, and large-connection Internet of Things services. The satellite Internet of Things takes advantage of the satellite communication network to achieve global coverage, makes up for the limited coverage of the ground communication network, provides global all-weather Internet of Things access services, and expands a wider range of application scenarios for the Internet of Things. The Internet of Things is not affected by weather and climate environment, has all-weather service capabilities, and the system has strong disaster resistance. From the perspective of satellite communication,...

AI Technical Summary

Problems solved by technology

The open-loop frequency compensation method is that the terminal estimates the Doppler frequency shift of the uplink signal according to the Doppler frequency shift of the downlink signal to perform frequency compensation. This method is based on the premise of an ideal clock source and does not consider the clock difference between the satellite and the terminal. The frequency offset from the terminal causes the problem of too large protection bandwidth and low precision; the closed-loop frequency compensation method is that the satellite returns the frequency difference of the terminal according to the signal sent by the terminal, and through the closed-loop frequency compensation, the terminal frequency compensation accuracy meets the requirements. This method compensates The accuracy is relatively high, but there are problems of high signaling overhead and power consumption. That is to say, the existing frequency compensation technology fails to achieve a balance between accuracy, signaling overhead, and power consumption.

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