Linear frequency sweep signal basic parameter estimation method and device abased on rearranged time-frequency spectrum

Abstract

The invention discloses a linear frequency sweep signal basic parameter estimation method and device abased on a rearranged time-frequency spectrum, wherein the method comprises the following steps of: setting a wind function length; obtaining the rearranged time-frequency spectrum; obtaining a row number and a column number of an analysis spectrum; obtaining the row coordinate with the maximum absolute value in each column by a peak scanning method; obtaining a sampling frequency, and obtaining an equal difference frequency sequence; generating an equal difference sequence, and obtaining an instant frequency; based on a least square method, obtaining a fitting instant frequency, and obtaining a frequency modulation rate; and according to the fitting instant frequency closest to the middle time moment from the left side and the frequency modulation rate, obtaining a starting frequency. By adopting the estimation method, the high precision is maintained under a high noise background, the estimation precision is improved, and the method is simple and convenient.

Description

technical field [0001] The invention relates to the technical field of one-dimensional signal processing, in particular to a method and device for estimating basic parameters of a linear frequency sweep signal based on rearranged time spectrum. Background technique [0002] Chirp signals are used in a wide variety of applications. First, since the Doppler modulation frequency is approximately proportional to the target speed, the target speed can be calculated by estimating the Doppler modulation frequency, and the Doppler modulation frequency can be calculated according to the modulation frequency. Secondly, chirp signals are also used in many research fields such as radar, communication, sonar, and geological exploration. Therefore, it is of extremely important engineering value to estimate the basic parameters of the chirp signal. [0003] In related technologies, the methods for calculating the basic parameters of the chirp signal mainly include Hough transform methods...

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Problems solved by technology

However, based on various time-frequency transform Hough transform methods, since the calculation accuracy of Hough transform depends on the number of time-frequency coefficients in the time-frequency plane, improving the calculation accuracy will increase the calculation of the two processes of time-frequency transform and Hough transform transformation. amount, and the amount of calculation increases in a non-linear manner, so high precision will inevitably bring a large amount of calculation; for the method based on fractional Fourier transform, the aggregation characteristics of the chirp signal in the time-frequency domain can be fully utilized, and the signal can be estimated at the same time The tuning frequency and starting frequency parameters, but this method requires two-dimensional search of the fractional Fourier transform under different rotation angles, the amount of calculation is large, and the accuracy of parameter estimation is limited by the inherent resolution

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