High precision time difference calibrating method based on FPGA

Abstract

The present invention relates to an absolute time difference processing algorithm that is a high-precision time calibration method based on FPGA by using a prevalent processor FPGA chip, especially relates to a high-precision clock source leading phase processing algorithm. The present invention can realize a relative time difference calibration and an absolute time difference calibration at the same time by using a high-accuracy clock source leading phase processing algorithm, the main time difference calibration algorithm is performed by FPGA, leading phase time difference especially the time difference leading up by one FPGA working clock period is converted into a legging time difference through the cooperation of DSP and is performed with an on-second calibration by a FPGA to obtain high-accuracy time reference pulses and a time thereof, before the calibration of leading time difference of which the absolute value is smaller than a period of time reference pulses, time and reference time synchronization can be realized, therefore, the method has characteristics of reduced ground injection frequency, fast inter-constellation synchronization and high real-time performance, and realizes the constellation time synchronization.

Description

technical field [0001] The invention relates to a high-precision time difference calibration method, in particular to an FPGA-based high-precision time difference calibration method, which is mainly used for high-precision time difference calibration. Background technique [0002] At present, in the ground time system, the time management in the satellite constellation, and the time synchronization system between the satellite and the ground, almost all of them need to be calibrated for the time difference. The calibration of time difference is applied in many time systems at home and abroad, and the most widely used is the time service system recognized by various countries and even internationally, but there is no public literature that introduces the time difference processing algorithm in detail. [0003] "Measurement and Calibration of GPS Fundamental Frequency Standard" published in Volume 27, Issue 5 of "Aerospace Measuring Technology" in October 2007 introduced a com...

AI Technical Summary

Problems solved by technology

[0005] The time difference calibration technology learned from public publications and public channels is as follows: First, adopt phase-locked loop / frequency-locked loop phase modulation technology and timing technology, realize time difference calibration through software, phase-locked loop / frequency-locked loop phase modulation technology It is already relatively mature, and can obtain high-precision phase modulation accuracy, but the phase-locked loop / frequency-locked loop phase modulation technology requires two input signals (one local signal, one reference signal); the other is to use phase modulation technology to achieve The time is relatively synchronized (regardless of the absolute time difference), but the specific implementation scheme and algorithm are not described in the introduction

[0006] The deficiencies of existing literature at home and abroad are: (1) no detailed time difference processing algorithm, especially the introduction of the algorithm for simultaneous calibration of absolute time difference and relative time difference; (2) no introduction of specific implementation schemes and designs of related algorithms

Images