INS auxiliary Beidou signal capturing method

Abstract

The invention discloses an INS auxiliary Beidou signal capturing method. The method includes the steps that firstly Doppler frequency generated by movements of a carrier and a satellite is calculated; the Doppler frequency is transmitted to a capturing loop of a receiver, and a carrier NCO of the loop adjusts carrier frequency; frequency mixing is conducted on intermediate frequency signals and local carrier signals to acquire in-phase signals and orthogonal signals, and the in-phase signals and the orthogonal signals correlation operations with local signals conduct respectively; correlation values acquired by each operation are stored in a cache to acquire an M*N matrix; correlation values of the in-phase branch and the orthogonal branch form a plural matrix, and whether the signals enter a tracking module or the signals are recaptured is judged until the signals are captured. The advantage of combining time domain capture and frequency domain capture is fully exerted, and a matching filter set is adopted in the matching process, so that capturing time is saved, and rapid capture of the signals in a high dynamic environment can be rapidly achieved; the correlation values of the in-phase signals and the orthogonal signals are combined in the matrix to conduct FFT conversion, so that hardware resources are saved.

Description

technical field [0001] The invention belongs to the field of satellite navigation, and in particular relates to a method for capturing Beidou signals assisted by INS. Background technique [0002] The high-tech characteristics of modern warfare show that precision-guided weapons with navigation and positioning technology as the core information source have become the dominant force in warfare, and cost-effective navigation and guidance modules are one of the key technologies for precision-guided weapons. [0003] How to capture satellite signals in a highly dynamic environment is an urgent problem for navigation receivers. Due to the high-speed movement between the carrier and the satellite, the signal produces a large Doppler frequency shift, and the frequency-domain search bandwidth will become very large when the signal is captured, which increases the number of frequency-domain search points and gives the receiver a fast capture range. Great difficulty came. [0004] W...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a method for fast acquisition of Beidou signals assisted by INS, aiming at solving the problem of fast acquisition of signals in a high dynamic environment

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