Research On The Methods Of Modeling And Estimation Of Underwater Acoustic Channel

With the further research and development of oceans, the importance of the performance of underwater acoustic communication system has got higher attention. The underwater acoustic channel is featured with a long delay, limited available bandwidth, high ambient background noise, and so on. These complex factors have seriously affected the quality of underwater acoustic communication and greatly restricted the application and development of underwater acoustic communication technology with the respect to the following two aspects: the traditional method of underwater acoustic channel modeling application is not effective due to restrictions such as environmental conditions; the traditional method of underwater acoustic channel estimation is also not effective due to the bigger estimated error.This paper firstly analyzes the major important characteristics of underwater acoustic channel, and briefly describes the technology at this stage in the field of underwater acoustic communication applications, and then focuses on the underwater acoustic OFDM communication system. As for the modeling of underwater acoustic channel, the traditional acoustic channel modeling method is introduced, and the underwater acoustic channel modeling based on BELLHOP is proposed. In the aspect of underwater acoustic channel estimation,this paper applies compressed sensing theory, which is the new theory in the field of signal and information processing, into the underwater acoustic channel estimation, and puts forward channel estimation method of underwater acoustic OFDM communication system based on compressed sensing theory. This method inserts the two-dimensional pilot by linear interpolation method, uses the channel perception to obtain the frequency domain response of channel sampling values constructs the corresponding complete dictionary, and uses compressed samples matching pursuit algorithm to complete the channel estimation of underwater acoustic OFDM communication system effectively.At last, we realize the underwater acoustic channel modeling and channel estimation. And the experimental results show that underwater acoustic channel modeling based on the BELLHOP model can effectively describe the marine acoustic environment characteristics; the channel estimation method of underwater acoustic OFDM communication system based on compressed sensing theory is more effective and more suitable for underwater acoustic communication than other methods, considering the factors such as the recovery accuracy, the error rate, the algorithm complexity and stability.