원문정보
초록
영어
A method is promoted to eliminate the noise of the speech signal in the orthogonal frequency division multiplexing (OFDM) underwater acoustic communication system based on the wavelet packet decomposition and reconstruction. The wavelet packet decomposition is accomplished by analyzing the different wavelet transform coefficient distribution characteristics of the signal and the noise. The speech signal is stratified to determine the best wavelet packet decomposition tree, the threshold value is quantified, and the wavelet packet decomposition is completed. The threshold value can be used to eliminate signal noise. Finally, the transmitted signal is reconstructed by the inverse transformation of the wavelet packet. The computer simulation results show that the method of wavelet packet decomposition is worked for the speech signal processing in the OFDM underwater acoustic communication system. For the speech signal transferred in the underwater acoustic channel, the noise can be eliminated and the valid signal can be kept effectively.
목차
1. Introduction
2. The Principle of De-noising OFDM Underwater Acoustic Communication System
2.1. The Principle of OFDM
2.2. The Principle of Wavelet Packet
2.3. The Principle of the Method Mentioned in this Paper
3. Channel Model
4. Simulations
5. Conclusion
Acknowledgements
References