A High Dynamic and Accurate Acquisition Method of Composite Carrier Navigation Signal

Abstract

The present invention provides a high dynamic fast / accurate capture method for NSCC signals. The specific process is: according to the selected frequency band to be analyzed, respectively perform Zoom-FFT operation on each subcarrier in the NSCC digital intermediate frequency signal to obtain refined spectrum information; search Zoom ‑After the FFT operation, read the peak point in the frequency domain, read the frequency corresponding to the peak point, center on the frequency corresponding to the peak point, and determine the frequency point range to be monitored and updated according to the Doppler dynamic range; execute SlidingFFT for the frequency point range to be monitored and updated Operation, real-time and accurate estimation of the frequency information of each subcarrier of NSCC in sliding recursive mode, and update / monitoring of the peak value of each subcarrier of NSCC; use the peak point and its adjacent peak information to perform interpolation estimation based on the sinc function; based on the interpolation estimation result, obtain The real-time accurate Doppler frequency shift value of each subcarrier of NSCC realizes high dynamic precision capture. The method of the invention can realize the accurate estimation of the Doppler frequency shift of each carrier of the NSCC in the acquisition stage with a small calculation 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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