Method and system for capturing aperiodic long code signal of satellite navigation receiver

Abstract

The invention discloses a method and a system for capturing an aperiodic long code signal of a satellite navigation receiver. The method comprises the following steps: S1, in a rapid search stage, carrying out segmented correlation accumulation by using relatively short coherent integration time, carrying out rapid Fourier transform, envelope taking and post-accumulation processing on a segmented correlation value, and maximizing a frequency spectrum envelope to obtain a Doppler frequency initial estimation value under a current code phase; s2, a false alarm verification stage: accumulating a plurality of segmented correlation values after phase rotation in the fast search stage to obtain a segmented correlation value with longer coherent integral time, similarly performing fast Fourier transform, envelope taking and post-accumulation processing, performing capture judgment by using a spectrum envelope maximum value, and when the envelope maximum value exceeds a capture threshold, performing false alarm verification, outputting the current code phase and Doppler frequency as a signal capturing result. Under the condition that the Doppler search range is guaranteed, high detection performance can be achieved, and two-stage detection is achieved under the condition that correlator resources are not increased.

Description

technical field [0001] The present invention relates to the technical field of satellite navigation, and more specifically, relates to a method and system for capturing non-period long code signals of a satellite navigation receiver. Background technique [0002] Unlike civil public signals using short codes, the authorized signals of each satellite navigation system use non-periodic long codes. Under normal circumstances, when the satellite navigation receiver receives the aperiodic long code, it needs to receive the civil signal first, and demodulate the specific current accurate time from the civil signal, but in some cases the civil signal may not be available, or for To prevent being deceived, the authorized signal receiver will directly capture the authorized signal. [0003] For direct capture of authorized signals, the time uncertainty range is usually . In order to complete such a large-scale code phase search in a relatively short period of time, the acquisitio...

AI Technical Summary

Problems solved by technology

When the receiver dynamic range is large, multiple acquisitions are required, which significantly affects the acquisition time

Therefore, in the traditional acquisition module implementation architecture, it is difficult to balance the detection performance and Doppler search range

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