| In the distributed underwater explosion test system, for the purpose of the information reconstruction in the test waters, it is meaningful to obtain the test information on the basis of identifying the relative position of the test base station in the test waters. It is necessary to design the positioning system which represents the characteristics, which can response the real-time changes in the base station location information. for the purpose,the floating base station is designed. The article focuses on the designing of the positioning system beacon signal encoding module,which manages the low power consumption,small size according to the floating base station self-positioning system.First,the article introduces the overall and structure of the floating base self-positioning system. according to the underwater acoustic signal transmission affected by the factors and the characteristics of the self-positioning system,the article establishes the positioning beacon signal mode. For the feature of the self-positioning system to be scalable, the CDMA positioning beacon signal encoding method is being used. The system can expand the numbers of the buoy base stations to expand measuring range. By the contrast of the signal output of the sine wave modulated circuit and the square wave modulated,the latter is proposed and conformed to be as the positioning beacon signal transmitter module. The experiment shows that positioning beacon signal transmitter unit conforms the positioning beacon signal requirements of the positioning system with the low power consumption and low cost requirements. According to the positioning beacon signals,the signal processing method based on the sampling points is being used.The self-positioning system experiment shows that the positioning beacon signal transmitter unit can meet the system requirement. The inter-symbol interface attenuates heavily in the beacon signal transmission. The signal encoding error ranges from 0.1m to 1.2m in the 200 meters. |
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