High-dynamic precise acquisition method for composite carrier navigation signal

Abstract

The present invention provides a high-dynamic fast/precise acquisition method for an NSCC signal. The method comprises a step of performing a Zoom-FFT operation on each subcarrier in an NSCC digital intermediate frequency signal according to a selected frequency band to be analyzed and obtaining refined spectral information, a step of searching for a frequency domain peak point after the Zoom-FFToperation, reading a peak point corresponding frequency, and determining a frequency range to be updated and monitored with the peak point corresponding frequency as a center according to a Doppler dynamic change range, a step of performing a sliding FFT operation on the frequency range to be updated and monitored to accurately estimate the frequency information of each subcarrier of the NSCC in real time in a sliding recursive mode to complete the update/monitoring of each subcarrier peak of the NSCC, a step of carrying out interpolation estimation based on a sinc function by using the peak point and adjacent peak information, and a step of obtaining the real-time precise Doppler shift value of each subcarrier of the NSCC based on an interpolation result to achieve high-dynamic precise acquisition. According to the method, the accurate estimation of the Doppler shift of each carrier of the NSCC during an acquisition phase can be achieved with a small computational cost.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a method for high dynamic and precise acquisition of a composite carrier navigation signal. Background technique [0002] As a ground receiving and calculating device, the navigation receiver can reflect the accuracy and performance that the navigation system can achieve to a certain extent. The baseband digital signal processing unit is the core module of the receiver, and the design of related synchronization algorithms directly affects the key performance indicators of the receiver, and its importance cannot be ignored. [0003] Acquisition is the first step of the baseband processing module, and its function is positioned as expected signal detection and rough estimation of signal parameters (Doppler frequency shift and pseudo-random code phase), providing initial values ​​for subsequent tracking steps. Acquisition is the most computationally intensive proc...

AI Technical Summary

Problems solved by technology

However, there is a contradiction between the frequency resolution and the amount of calculation (rapidity) in the FFT frequency domain capture algorithm. To improve the accuracy of frequency domain analysis will inevitably increase the signal processing length and increase the calculation burden.

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