High-precision Estimation Method of Beidou Satellite Signal Carrier Frequency at b1 Frequency Point

Abstract

The invention relates to a Beidou B1 frequency point satellite signal carrier frequency high-accuracy estimation method. The method includes the following steps that: inputted Beidou digital intermediate-frequency signals are mixed with local oscillation carriers; cyclic cross-correlation is performed on mixed signals and a local ranging code sequence in the frequency domain; the modulus of coarse baseband signals is obtained in the time domain, a ranging code phase and a carrier frequency which are corresponding a correlation peak are searched from an obtained result; a local ranging code is generated through using a known code phase and is multiplied with the coarse baseband signals in the time domain; the modulus of a multiplication result is obtained in the frequency domain, a carrier frequency corresponding to the correlation peak is searched from an obtained result; and correlation peak values corresponding to two frequency points before and after a carrier frequency point are compared with each other, a frequency search step is decreased step by step in the vicinity of a known carrier frequency point through using a binary search method, so that the carrier frequency is refined, and the accuracy of the carrier frequency can be stabilized in the range of more than ten Hz to tens of Hz. With the method adopted, the accuracy of Beidou satellite signal carrier frequency estimation can be effectively improved. The method has the advantages of fast and reliable capture and simplicity in implementation.

Description

technical field [0001] The invention belongs to the technical field of high-precision search and capture of satellite signal carrier frequencies by navigation receivers, and in particular relates to a high-precision estimation method for satellite signal carrier frequencies of Beidou B1 frequency point based on hybrid search combined with binary search. Background technique [0002] With the continuous development and application of new technologies of Beidou satellite navigation in my country, the development and realization of navigation receivers will face severe challenges. Among them, acquisition and tracking are the key technologies of receiver baseband signal processing, which will directly affect the performance of the receiver. In practical applications, due to the relative motion between the satellite and the user will cause Doppler frequency shift, if the user does not adjust the local recurring carrier frequency at the same time, then the correlation process of t...

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Problems solved by technology

The three methods have their own advantages and disadvantages, but the carrier frequencies obtained by the three methods are not accurate enough

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