A High-precision Blind Acquisition Method of Beidou Satellite Signal Based on Wavelet Transform

Abstract

The invention discloses a Beidou satellite signal high-precision blind capture method based on wavelet transform. The method comprises the steps that S1 a satellite signal is collected, and backgroundnoise reduction is carried out on a sampled signal through a wavelet threshold noise reduction method to acquire a noise-reduced sampled signal; S2 a model is established for the satellite signal received by a satellite receiver, and the model is converted into a single-input and multiple-output blind disjunctive model, and the noise-reduced sampled signal is used as the input signal of the blinddisjunctive model; S3 the blind disjunctive model is used to construct a new spatial spectral function, and the spatial spectral function is searched to acquire the frequency of the satellite signal;and S4 the initial phase of the signal is solved according to the frequency of the satellite signal to complete satellite capture. According to the invention, the blind disjunctive model and the wavelet transform theory are combined; a satellite signal blind separation method based on a subspace estimation algorithm is used to solve the Doppler effect frequency and phase of the Beidou satellite signal; and the method has the advantages of strong anti-noise ability, stable performance and high precision.

Description

technical field [0001] The invention relates to the field of satellite navigation, more specifically, to a high-precision blind acquisition method for Beidou satellite signals based on wavelet transform. Background technique [0002] In the 21st century, various fields such as national defense, civil aviation management and agriculture have made great progress, in which satellite navigation plays an active role. With the rapid increase of user demand for location services, the demand for rapid and real-time positioning of satellite navigation receivers in the civil and military fields continues to increase. On the one hand, because the signal acquisition Beidou satellite navigation receiver is the basic step of the baseband signal processing part, it is the premise of tracking and positioning, so the performance of the acquisition algorithm also directly determines the performance of the receiver such as acquisition speed and acquisition accuracy index. On the other hand, ...

AI Technical Summary

Problems solved by technology

On the other hand, because the satellite signal is in a strong noise environment, or is reflected by mountain buildings or blocked by trees during propagation, the signal strength will be much weaker than the normal signal at this time, resulting in the receiver being unable to obtain direct and effective satellite signals. Therefore, it is of great practical significance to improve the existing acquisition algorithm to improve the accuracy of satellite signal acquisition

[0003] Because the traditional serial and parallel acquisition algorithms are difficult to accurately capture such Beidou signals in noisy environments, especially in weak signal environments, the non-coherent cumulative acquisition method is usually used to improve the sensitivity of the acquisition. However, this method has defects. Because there is a square loss in the non-coherent accumulation method, the square loss increases with the increase of the number of accumulations, so the longer the accumulation time, the faster the noise will increase, and the capture accuracy will decrease. Therefore, it is impossible for this method to increase the accumulation time infinitely. Improve capture success rate

Images