Using Wavelet Packet Decomposition Technique on Fuzzy Classify Model for Underwater Acoustic Signal Recognition

A0021 Chu-Kuei Tu Department of Information and Computer Engineering, Chung Yuan University

A0022 Liang-Ching Lin Department of Information and Computer Engineering, Chung Yuan University

Underwater acoustic signal is affected by reverberation, inhomogeneity

and other various factors causing by the ocean environment, therefore,

it reveal characteristics of non-linear and time-variant. Hence, a

real time fuzzy logic recognition system is developed. The functions

of the proposed system include two subjects, the first subject is

underwater acoustic signal feature extraction by using of wavelet

packet decomposition, the second subject is underwater signal pattern

recognition by using of fuzzy logic model. Finally, combine two parts

and establish a practical, real time underwater Acoustic recognition


During the feature parameter extraction stage, signal characteristic

analysis and feature extraction are studied. The results proved that

using wavelet packet decomposition method for feature extraction can

obtain multi-resolution characteristics, this is the keypoint that the

system can identify the different ships signature effectively.

Besides, by using of the self-organization map neural network, the

input feature data are clustering, and the centers of data set are

generate which are the templates of feature parameters. During the

underwater signal pattern recognition stage, signal identification is

performed by using of fuzzy logic theory. Furthermore, by defining

the linguistic variables of the feature and the membership function of

the fuzzy rules, a fuzzy logic algorithm is developed for the purpose

of underwater signal recognition.

A simulation is designed using ships signature as input data, the

results have demonstrated the effective performance of proposed system.

Following the analysis of the results, conclusions and recommendations

will be provided. The proposed system can be used to analysis and

recognize an underwater acoustic signal, which may encounter in the

area of ocean Engineering and environment measurement.