Evaluation of Gabor Transform Filter Threshold Identified by Initial Highest Inter-Cluster Distance Probability

2011 ◽  
Vol 204-210 ◽  
pp. 1166-1169
Author(s):  
Di Fan ◽  
Chang Zhi Lv ◽  
Mao Yong Cao

Gabor transform is very suitable for time-frequency analysis and good for filtering non-stationary signals. The threshold of the Gabor transform filter is a key factor for the filter’s effectiveness. A novel threshold based on initial highest inter-cluster distance probability (IH-ICDP) is described in this paper and it can make the filter more efficient. Some experiments have been carried out under several conditions to evaluate the new threshold’s characteristics. The experimental results show that Gabor transform filter with this proposed threshold works better than wavelet transform filter, especially when the signal’s SNR is very low. From the evaluation results, it is possible to consider that the threshold presented is optimal or nearly optimal.

2011 ◽  
Vol 467-469 ◽  
pp. 1985-1990 ◽  
Author(s):  
Di Fan ◽  
Mao Yong Cao ◽  
Lax Misha Rai

Gabor transform suitable for time-frequency analysis and good for filtering non-stationary signals. The threshold of the Gabor transform filter is a key factor for the filter’s effectiveness. The popularly used threshold obtained by linear method is not suitable for non-stationary signals with low signal to noise ratio (SNR) because, it cannot separate the expansion coefficients of noise and useful signals. In this paper, a novel method to identify Gabor transform filter’s threshold based on initial highest inter-cluster distance probability is proposed. Simulation experiments have been carried out under several conditions. The experimental results show that the proposed threshold is highly suitable, especially when the signal’s SNR is very low and the filter output is very consistent to the real original signal and keeps no pseudo signal in zero regions.


2013 ◽  
Vol 805-806 ◽  
pp. 1962-1965 ◽  
Author(s):  
Hui Xing Zhang ◽  
Jie Li ◽  
Qi Lin ◽  
Jian Zhi Qu ◽  
Qi Zheng Yang

Time-frequency analysis is a powerful tool for analyzing non-stationary signals, which can describe the signals frequency varying with time and provide us the joint information of time domain and frequency domain of the signal. We use a synthetic signal to realize the time-frequency analysis methods of wavelet transform, S transform and Wigner-Ville distribution. Through comparing and analyzing those time-frequency distributions, we propose a new method of integrating wavelet transform and Wigner-Ville distribution. This new method gives a better result than that of wavelet transform and Wigner-Ville distribution and increases the time-frequency resolution.


1997 ◽  
Vol 117 (3) ◽  
pp. 338-345 ◽  
Author(s):  
Masatake Kawada ◽  
Masakazu Wada ◽  
Zen-Ichiro Kawasaki ◽  
Kenji Matsu-ura ◽  
Makoto Kawasaki

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