Beidou weak signal capture method based on difference correlation integral

Abstract

The present invention discloses a Beidou weak signal capture method based on a difference correlation integral. The Beidou weak signal capture method is obtained through improvement of the traditional difference correlation integral algorithm, the difference correlation integral operation is performed through adoption of the sample point delay mode to weaken the influences of Beidou signal NH code hopping and bit hopping; and the integral time is prolonged to improve the signal-to-noise ratio of signals; and moreover, the FFT algorithm is employed to realize the parallel searching of the code phases and the carrier frequency so as to greatly shorten the capture time compared to the traditional capture algorithm. The Beidou weak signal capture method based on the difference correlation integral is suitable for all the Beidou civil signals with no need for considering the difference of the GEO and non-GEO navigation message.

Description

technical field [0001] The invention relates to a Beidou weak signal acquisition method based on differential correlation integration, and belongs to the technical field of signal baseband processing of satellite navigation receivers. Background technique [0002] With the development of satellite navigation systems, the development of high-performance receivers has become a research hotspot at home and abroad, and the high-sensitivity receiver for weak signals is one of the hotspots. In recent years, many experts and scholars at home and abroad have carried out research on high-sensitivity GPS receivers. With the development of the Beidou navigation system, the high-sensitivity Beidou navigation receiver for weak signals has certain theoretical value and application prospects. [0003] Prolonging the coherent integration time is a commonly used method for high-sensitivity receivers to improve the signal-to-noise ratio, and at the same time, it can reduce the data rate and ...

AI Technical Summary

Problems solved by technology

[0005] On the other hand, the NH code (New Hoffman code) with a rate of 1kbps is modulated by the secondary encoding of the D1 navigation message broadcast by Beidou MEO and IGSO satellite signals, which can improve the resistance to narrow-band interference and improve the cross-correlation between satellite signals characteristics, but at the same time cause the coherent integration time to be affected by the NH code phase jump, and the coherent integration time is limited to 1ms without removing the NH code

Images