Beidou weak signal capturing method and system

Abstract

The invention belongs to the technical field of satellite navigation, and discloses a Beidou weak signal capturing method and system.The method comprises the steps that firstly, carrier stripping is conducted on sampled data, chip merging is conducted, then repeated utilization, Doppler stripping and data folding of code merging data are achieved through an overlapping and folding method, and consumption of hardware resources is reduced; and carrying out code parallel coherence on the data block and the local pseudo code through FFT and IFFT to obtain coherence values of all code phases. Performing difference on coherent values of different code phases through an inter-symbol difference algorithm to avoid the influence of NH code hopping and navigation data hopping; performing coherence on the differential data after Doppler compensation, improving the signal-to-noise ratio of the signal, performing incoherence on the data, improving the capture sensitivity, and finally judging whether to capture the satellite signal or not through threshold judgment. According to the invention, Beidou D2 navigation data of-146dBm and D1 navigation data of-145dBm are finally captured.

Description

technical field [0001] The invention belongs to the technical field of satellite navigation, and in particular relates to a Beidou weak signal acquisition method and system. Background technique [0002] At present, with the rapid development of satellite navigation systems, satellite navigation receivers are gradually applied in various fields, and navigation receivers used in the aerospace field have also developed rapidly. In the high-orbit environment, due to the occlusion of the earth, most of the main lobe signal cannot be received by the receiver, and the side lobe signal strength is extremely weak. In order to allow the receiver to normally complete the positioning and solution requirements, it poses a great challenge to the acquisition sensitivity of the navigation receiver. At the same time, with the vigorous development of my country's aerospace industry, the development and design of a high-sensitivity navigation receiver can reduce the cost of spacecraft and sa...

AI Technical Summary

Problems solved by technology

[0005] (1) The traditional Beidou navigation receiver uses the delay difference and zero padding method to capture Beidou satellite signals, which consumes a lot of hardware resources;

[0006] (2) The traditional navigation receiver has insufficient acquisition sensitivity due to the structure of the algorithm;

[0007] (3) Due to the high speed of the D2 navigation message, the traditional navigation receiver cannot capture the D2 navigation message with high sensitivity

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