Extension of low-SNR coherent signal detection method based on spectral matrix analysis by using wavelet transformation and time delay coordinate

2021 ◽  
Author(s):  
Takayuki Nagata ◽  
Yusuke Mukuhira ◽  
Taku Nonomura
2014 ◽  
Vol 577 ◽  
pp. 810-815
Author(s):  
Zhen Gang Li

Target detection in the presence of strong seabed reverberation is a hot research topic nowadays. This kind of target detection method is similar to signal detection with known shape and unknown parameters under non-WGN or coherent signal detection in reverberation. When a LFM signal is choose as transmitted signal, target echo has excellent time-frequency focusing property on a certain rotating angle and reverberation could lose its original linear modulation property. LFM signal can be transformed to a sine signal with some rank FrFT. Since FrFT is a linear transform, interference including reverberation and noise will keep former statistic characteristics. So LFM signal detection is thus equivalent to detection of sine signals in absence of colored noise. The reverberation will be easily erased and target echo will be preserved. Based on the analysis above all, a sub-optimum detector based on reverberation-whiten in FrFT field is advanced. The validity of these conclusions is validated by computer simulations. A satisfying result is achieved.


1976 ◽  
Vol 19 (3) ◽  
pp. 246-251 ◽  
Author(s):  
Helen H. Molinari ◽  
Andrew J. Rózsa ◽  
Dan R. Kenshalo

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 949
Author(s):  
Jiangyi Wang ◽  
Min Liu ◽  
Xinwu Zeng ◽  
Xiaoqiang Hua

Convolutional neural networks have powerful performances in many visual tasks because of their hierarchical structures and powerful feature extraction capabilities. SPD (symmetric positive definition) matrix is paid attention to in visual classification, because it has excellent ability to learn proper statistical representation and distinguish samples with different information. In this paper, a deep neural network signal detection method based on spectral convolution features is proposed. In this method, local features extracted from convolutional neural network are used to construct the SPD matrix, and a deep learning algorithm for the SPD matrix is used to detect target signals. Feature maps extracted by two kinds of convolutional neural network models are applied in this study. Based on this method, signal detection has become a binary classification problem of signals in samples. In order to prove the availability and superiority of this method, simulated and semi-physical simulated data sets are used. The results show that, under low SCR (signal-to-clutter ratio), compared with the spectral signal detection method based on the deep neural network, this method can obtain a gain of 0.5–2 dB on simulated data sets and semi-physical simulated data sets.


2014 ◽  
Vol 989-994 ◽  
pp. 4001-4004 ◽  
Author(s):  
Yan Jun Wu ◽  
Gang Fu ◽  
Yu Ming Zhu

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.


1990 ◽  
Vol 88 (6) ◽  
pp. 2692-2694 ◽  
Author(s):  
Isabel M. G. Lourtie ◽  
G. Clifford Carter
Keyword(s):  

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