High-precision high-order time rearrangement synchronous extrusion transformation time-frequency analysis method

A technology of synchronous extrusion and time-frequency analysis, which is applied in the field of signal processing, can solve problems affecting signal processing effects and limited GD estimation accuracy, and achieve the effects of improving time-frequency readability, suppressing energy divergence, and good consistency

Active Publication Date: 2020-06-16
CHENGDU UNIVERSITY OF TECHNOLOGY
View PDF12 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method has limited accuracy for GD estimation, which will affect the final signal processing effect

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • High-precision high-order time rearrangement synchronous extrusion transformation time-frequency analysis method
  • High-precision high-order time rearrangement synchronous extrusion transformation time-frequency analysis method
  • High-precision high-order time rearrangement synchronous extrusion transformation time-frequency analysis method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] Example 1: see figure 1 , a high-precision high-order time rearrangement synchronous squeeze transform time-frequency analysis method, comprising the following steps:

[0050] (1) Obtain a time-domain signal x(t), perform Fourier transform to obtain a frequency-domain signal X(ω), t is time, and ω is frequency;

[0051] (2) Select order N and frequency window function G(ω), calculate X(ω) at ω k Short-time Fourier transform under G(ω) to obtain different time-frequency values ​​corresponding to time-frequency points (t,ω) Where N is a positive integer, k=0,1,2,...,max{1,2N-2}, and when k=0, G(ω)=ω 0 G(ω), use Construct N order square matrix α N (t,ω) and β N (t,ω);

[0052]

[0053]

[0054] In the formula, s is the adjustment factor in the window function G(ω);

[0055] (3) Using the N-order square matrix α N (t,ω) and β N (t,ω) to calculate the Nth order group delay estimate

[0056] When β N When the determinant value of (t,ω) is not zero, th...

Embodiment 2

[0060] Embodiment 2: It also includes step (6), obtaining the reconstructed signal x'(t) through N-order time rearrangement and synchronous squeezing inverse transformation. All the other are identical with embodiment 1.

Embodiment 3

[0061] Embodiment 3: This embodiment is the same as Embodiment 2, the difference is that in step (2), Obtained by the following formula;

[0062]

[0063]

[0064] In the formula, v is a frequency variable and is independent of the value of ω, i is the imaginary number unit, G * (ω) represents taking the complex conjugate of G(ω).

[0065] In step (3), the N-order group delay estimation is specifically calculated using the following formula

[0066]

[0067] In the formula, Im means to take the imaginary part of the complex number.

[0068] In step (4), specifically use the following formula to obtain the N-order time rearrangement synchronous extrusion transformation

[0069]

[0070] In the formula, u is a time variable, and it is a different time variable that has nothing to do with the value of t, and the function σ(x) is a Dirac function.

[0071] In step (6), specifically adopt the following formula to obtain the reconstructed signal x'(t);

[0072]...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a high-precision high-order time rearrangement synchronous extrusion transformation time-frequency analysis method. The method comprises the steps: converting a signal x (t) into a frequency domain signal X (omega); selecting an order number N and a frequency window function G (omega), calculating short-time Fourier transform of the X (omega) under omega<k>G (omega), constructing square matrixes alpha N (t, omega) and beta N (t, omega), and calculating N-order group delay estimation; superposing a time-frequency value to a GD estimation position along a time direction,and calculating N-order time rearrangement synchronous extrusion transform to obtain a time-frequency spectrum; and reconstructing the signal. According to the invention, a novel GD estimation methodis provided, the estimation precision of the rapidly changing GD is improved; and the time-frequency spectrum energy is rearranged in the time direction to be gathered near the real GD, so that the energy diffusion is effectively inhibited, and the time-frequency readability is improved. The invention further provides a reconstruction method, and the reconstruction signal is high in reduction degree.

Description

technical field [0001] The invention relates to a signal processing method, in particular to a high-precision high-order time rearrangement synchronous extrusion transformation time-frequency analysis method. Background technique [0002] Time-frequency analysis has always been an important research method for modern non-stationary signal analysis and processing. Currently commonly used time-frequency analysis methods mainly include short-time Fourier transform (STFT), continuous wavelet transform (CWT), S-transform (ST), etc. These methods based on window functions have certain defects, and are affected by the window function itself. The time-frequency resolution is limited, and the energy aggregation of the time-frequency spectrum is limited, so it is difficult to accurately extract the characteristics of the signal. [0003] In order to improve the effect of time-frequency analysis, Kodera et al. proposed a time-frequency rearrangement method, which improves the time-fre...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01R23/02G06F17/16
CPCG01R23/02G06F17/16
Inventor 陈辉胡英杨超陈旭平冯俊魏友华郭科
Owner CHENGDU UNIVERSITY OF TECHNOLOGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap