The Research Of Acoustic Signal Coding And Transmission Characteristics

With the progress of socialist modernization construction in China, the development of marine resources has increasingly attracted attention. On marine projects, people care about what happens in some location. But if you can not determine the location of the sensor in the base station, the information collected is not practical significance. It is necessary to study the position of the base station, which are constructed by the wireless sensor network. In addition, because the complex and changeable marine environment are affected by the sea, waves, tides and weather and other factors, the location of the buoy base station have to change at any time. While, there are the close relation to the change of their position and the reconstruction of information in space-time. So the issue how accurately the location of base station positioning is necessary to be resolved.First, this article introduced the basic principles and overall structure of the self-positioning system in the floating base station. And then the encoding and transmission of positioning signal have been designed. On this basis the core of the self-positioning system, acoustic positioning signals to send and receive system, has been designed. In this system, it can complete self-positioning of base stations in frequency division multiplexing mode, by the principle of waveform memory. And the system can send the signal in code division multiplexing mode in theory, so it has a certain expansion of capacity. When the analysis of positioning signal have been done, a data processing method has been presented, which is based on sampling point difference, and the experiments show that the approach can be higher positioning accuracy.Finally, the overall system is tested in the river. The experiments have proved that the floating base station can be located by itself completely and, by using the positioning system designed in the paper. It can achieve the distance which is 200 meters times 200 meters, and the data processing program presented in the paper can control the positioning accuracy of less than 0.2 milliseconds. The position system have low power and high precision features, and it make the system would occupy a significant position in the marine environment observation, resource exploration and underwater communication.