Method and device for capturing weak signals

Abstract

The invention provides a method for capturing weak signals. According to the method, the Doppler frequency offset and the transmission time of a captured strong signal satellite are acquired; the Doppler frequency offset of a non-captured weak signal satellite can be determined according to the Doppler frequency offset of the captured strong signal satellite; a spreading code period and a spreading code phase of the non-captured weak signal satellite can be determined according to the transmission time of the captured strong signal satellite. The invention further provides a device for capturing the weak signals.

Description

technical field [0001] The invention relates to an auxiliary Beidou satellite navigation technology, in particular to a method and device for capturing weak signals. Background technique [0002] At present, with people's requirements for weak signal environments such as indoors and first positioning time, Assisted-Global Navigation Satellite System (A-GNSS) has emerged as the times require. A-GNSS provides the required auxiliary information for the navigation receiver by means of the wireless communication network to support the positioning ability of the navigation receiver or enhance the acquisition ability of the navigation receiver under weak signal conditions. [0003] Traditional navigation receivers need to capture 4 or more satellite signals to realize the positioning function, and different satellite signals have different pseudo-random codes with different start times and different Doppler frequency shifts. Therefore, in order to search for a certain satellite si...

AI Technical Summary

Problems solved by technology

[0006] However, in the coarse-time assisted positioning mode, the receiver cannot predict the code phase and the bit edge of the navigation message because the time accuracy is greater than the length of a ranging code. Therefore, under the same auxiliary information, the acquisition sensitivity will be lower than the precision Sensitivity captured while assisting

Moreover, due to weather, occlusion and other reasons in the actual environment, the power of many satellite signals is relatively weak, and often only one or two satellite signals that are slightly stronger can be captured, so the positioning cannot be completed

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