Circularity of the Fractional Fourier Transform and Spectrum Kurtosis for LFM Signal Detection in Gaussian Noise Model

2015 ◽  
Vol E98.A (12) ◽  
pp. 2709-2712 ◽  
Author(s):  
Guang Kuo LU ◽  
Man Lin XIAO ◽  
Ping WEI ◽  
Hong Shu LIAO
Keyword(s):  
Fourier Transform ◽  
Signal Detection ◽  
Gaussian Noise ◽  
Fractional Fourier Transform ◽  
Noise Model

LFM Signal Detection Method Based on Fractional Fourier Transform

2014 ◽  
Vol 989-994 ◽  
pp. 4001-4004 ◽  
Author(s):  
Yan Jun Wu ◽  
Gang Fu ◽  
Yu Ming Zhu
Keyword(s):  
Fourier Transform ◽  
Signal Detection ◽  
Frequency Analysis ◽  
Experimental Analysis ◽  
Fractional Fourier Transform ◽  
Detection Method ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Frequency Information ◽  
Strong Impulse

As a generalization of Fourier transform, the fractional Fourier Transform (FRFT) contains simultaneity the time-frequency information of the signal, and it is considered a new tool for time-frequency analysis. This paper discusses some steps of FRFT in signal detection based on the decomposition of FRFT. With the help of the property that a LFM signal can produce a strong impulse in the FRFT domain, the signal can be detected conveniently. Experimental analysis shows that the proposed method is effective in detecting LFM signals.

Study of VLF Communication Technique Based on FRFT

2014 ◽  
Vol 556-562 ◽  
pp. 5116-5120
Author(s):  
Yan Jun Wu ◽  
Gang Fu ◽  
Qian He
Keyword(s):  
Fourier Transform ◽  
Spread Spectrum ◽  
Fractional Fourier Transform ◽  
Noise Model ◽  
Channel Noise ◽  
Communication Signal ◽  
Atmospheric Noise ◽  
Communication Technique ◽  
Chirp Spread Spectrum ◽  
A New Technique

The atmospheric noise generated by lightning phenomena is the main source of interference in VLF communications, it is rather difficult to detect the communication signal that not only merged in strong channel noise, but probably interfered by high-tension impulse caused by thunder. This paper, Alpha stable distribution noise model is proposed to simulate atmospheric noise firstly, then, we study a new technique of Chirp Spread Spectrum (CSS) communication based on Fractional Fourier Transform (FRFT), This paper studies a new VLF communication technique of the Chirp Spread Spectrum (CSS) communication based on Fractional Fourier Transform (FRFT), and it demodulates message utilizing energy gathering property of chirp signal in FRFT domain.

Fractional Fourier Transform for Digital Image Recognition

2020 ◽  
Vol 34 (10) ◽  
pp. 2054025
Author(s):  
Luis Felipe López-Ávila ◽  
Josué Álvarez-Borrego
Keyword(s):  
Fourier Transform ◽  
Image Recognition ◽  
Gaussian Noise ◽  
Fractional Fourier Transform ◽  
Correlation Energy ◽  
Classical Correlation ◽  
Correlation Peak ◽  
Output Plane ◽  
Performance Metric ◽  
Salt And Pepper

In the image recognition field, there are several techniques that allow identifying patterns in digital images, correlation being one of them. In a correlation, you have to obtain an output plane that is as clean as possible. To measure the sharpness of the correlation peak and the cleanliness of the output plane, a performance metric called Peak to Correlation Energy (PCE) is used. In this paper, the fractional correlation is applied to recognize real phytoplankton images. This fractional correlation guarantees a higher PCE compared to the conventional correlation. The results of PCE are two-orders of magnitude higher than those obtained with the conventional correlation and manage to identify 91.23% of the images, while the conventional correlation only manages to identify 87.42% of them. This methodology was tested using images in salt and pepper or Gaussian noise, and the fractional correlation output plane always is cleaner and generates a better-defined correlation peak when compared with the classical correlation.

Simulation of VLF CSS System in Atmospheric Noise

2014 ◽  
Vol 556-562 ◽  
pp. 1874-1878
Author(s):  
Gang Fu ◽  
Yan Jun Wu ◽  
Qian He
Keyword(s):  
Fourier Transform ◽  
Spread Spectrum ◽  
Fractional Fourier Transform ◽  
Low Frequency ◽  
Noise Model ◽  
Channel Noise ◽  
Communication Signal ◽  
Atmospheric Noise ◽  
Communication Technique ◽  
Chirp Spread Spectrum

Very Low Frequency (VLF) communication is designed to operate in the frequency between 3 kHz and 30 kHz. The atmospheric noise generated by lightning phenomena is the main source of interference in VLF communications, it is rather difficult to detect the communication signal that not only merged in strong channel noise, but probably interfered by high-tension impulse caused by thunder. This paper, Alpha stable distribution noise model is proposed to simulate atmospheric noise firstly, then, we study a new technique of Chirp Spread Spectrum (CSS) communication based on Fractional Fourier Transform (FRFT), This paper studies a new VLF communication technique of the Chirp Spread Spectrum (CSS) communication based on Fractional Fourier Transform (FRFT), and it demodulates message utilizing energy gathering property of chirp signal in FRFT domain.

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