The Design Of Signal Processing System Of Underwater Acoustic Sensor Networks

Signal processing system of underwater acoustic sensor networks is an important part of the underwater explosion efficacy parameters testing system. The article is the design of signal processing system of underwater acoustic sensor networks based on Visual C++ 6.0 according to efficiency parameter testing system, which is the platform of signal analyzing, processing and positioning. It regards compression, decompression, coding and decoding method of underwater acoustic signal as the key research object. And the software of signal processing system of underwater acoustic sensor networks has been designed.The paper firstly has analyzed the characteristic of underwater acoustic signal, and then applies wavelet packet transform and the improved threshold principle to underwater acoustic signal compression. What has been principally discussed is how to select wavelet packet, wavelet packet decompression, the improved threshold principle. Finally, this algorithm is verified by underwater acoustic signal acquired though experiments. The result shows the algorithm could compress the water acoustical signal effectively.In order to accurately separate the information that each station transmits, the paper has also studies the algorithm of encoding and decoding of underwater acoustic signal, which has adopted the code division multiple access mode. The mode can counter multi-path interference effectively. According to the frequency range of hydrophone and figure of stations, PN code of n=5 have been chosen as address of a station, and the codes which relevant function value are smaller after shifted have been chosen as the address of others stations. Then, the thesis has introduced PN code capturing and decoding algorithms in detail. At last, do the simulation of coding and decoding in MATLAB, and address code is produced at random by the computer for three stations. The result shows that synchronism of PN code is very accurate and the decoding accuracy is high.