QFM signal parameter evaluation method based on four-order asymmetrical product type kernel function

Abstract

The invention belongs to the technical field of radar signal detection and evaluation, and particularly relates to a QFM signal parameter evaluation method based on a four-order asymmetrical product type kernel function. The method includes the steps of firstly, calculating the initial signal energy, setting a circulation initial value and establishing a matrix used for storing all subsequent component parameter estimation values; secondly, multiplying the time delay function of the four-order asymmetrical product type kernel function with the conjugation time delay function of the four-order asymmetrical product type kernel function, and conducting phase matching and converting on phases of the four-order asymmetrical product type kernel function, wherein the estimation values of the second parameters of the signal components can be obtained in the positions of frequency domain peak values; thirdly, constructing a new four-order asymmetrical product type kernel function for signals with compensation conducted on the second parameter estimation values, and conducting fast Fourier transform to obtain a frequency-frequency change rate two-dimensional distribution diagram, wherein third parameter estimation values and third parameter estimation values of the signal components can be obtained from the positions of the peak values; fourthly, filtering the signal components, estimated in the steps, out of the signal; fifthly, resetting cyclic variables and a signal, and calculating the ratio of the total energy of the signal to the initial signal energy.

Description

technical field [0001] The invention belongs to the technical field of radar signal detection and estimation, in particular to a QFM signal parameter estimation method based on a fourth-order asymmetric product kernel function. Background technique [0002] FM signal is a signal whose instantaneous frequency changes with time, so it is a typical non-stationary signal. According to the linear relationship between frequency modulation frequency and time, frequency modulation signals can be divided into two types of signals: linear frequency modulation and nonlinear frequency modulation. The QFM (Quadratic frequency modulated) signal, which has a quadratic function relationship between instantaneous frequency and time, is a signal commonly found in nature and artificial applications. It is used in sonar, high-resolution radar, seismic signal analysis, remote sensing and telemetry, communication It has a wide range of applications in engineering and science fields. [0003] Th...

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Problems solved by technology

In order to avoid the 3-dimensional objective function and the corresponding 3-dimensional maximum search, the cubic phase function (Cubic Phase Function, CPF) is proposed and used, but it cannot handle multi-component QFM signals; PHMT (Product High-Order Matched- Phase Transform) and PGCPF (Product Generalized Cubic Phase Function) methods can be applied to parameter estimation of multi-component QFM signals, but these two methods can only estimate the highest-order parameters after high-order nonlinear transformation, and cannot estimate other parameters at the same time , it is necessary to continuously search and estimate parameters of different orders through iterative compensation, and the compensation accuracy affects the estimation effect

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