Method and device for estimating frequency modulation ratio of linear frequency modulation signal

Abstract

The invention provides a method and a device for estimating the frequency modulation ratio of a linear frequency modulation signal. The method comprises the following steps: presetting a time delay set; determining a received current signal; performing autocorrelation operation on the current signal and each signal which is a set time delay from the current signal to get autocorrelation functions corresponding to the set time delays respectively; performing FFT operation on the autocorrelation functions corresponding to the set time delays to get corresponding fuzzy functions; determining the over-threshold peak positions in the fuzzy functions corresponding to the set time delays to get corresponding over-threshold peak position sets; judging the linear relationship between the over-threshold peak positions in the over-threshold peak position sets corresponding to the different set time delays, determining target over-threshold peak positions satisfying the linear relationship in the different set time delays, and forming a target over-threshold peak position set; and estimating the frequency modulation ratio according to the target over-threshold peak position set. With the method and the device, estimation within a large frequency range is realized, and the accuracy of frequency modulation ratio estimation is improved.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to a method and device for estimating the frequency modulation frequency of a linear frequency modulation signal. Background technique [0002] Linear frequency modulation signal (LFM, Linear Frequency Modulation, also known as chirp signal) is a common non-stationary signal with a large time-width bandwidth product; linear frequency modulation signal is widely used in radar, sonar, communication, jammer and other fields; Frequency modulation frequency is an important characteristic parameter of linear frequency modulation signal, and the estimation of frequency modulation frequency has always been the research content in the field of linear frequency modulation signal processing. [0003] At present, the method of estimating the frequency of chirp signals is mainly as follows: firstly, the frequency characteristics of short-term signals in multiple continuous windows are ...

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Problems solved by technology

The problem existing in the existing frequency modulation frequency estimation method is that the range of the estimated frequency modulation frequency is small. When the frequency modulation frequency is large, the chirp signal may have scanned the entire bandwidth in a window; another problem of the existing method is that when there is When there are multiple chirp signals, the frequency modulation frequency estimation may be misjudged; therefore, the application of the existing frequency modulation frequency estimation methods has certain limitations;

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