Design And Implementation Of Small Communication Sonar System

As people pay more and more attention to marine development.In order to facilitate the detection and collection of underwater resources,underwater acoustic technology also progressing.Because the analog modulation technology is easily affected by noise,communication tasks cannot be well performed in a poor underwater acoustic channel.Therefore,more and more underwater acoustic technologies use digital devices.The small communication sonar system adopts digital OFDM communication and can effectively counteract environmental noise.In this paper,aiming at the application needs of marine pastoral environment monitoring and high-speed data transmission.Design and implementation of a small-scale OFDM sonar device based on TMS320C6748.It can realize the collection of ocean hydrological conditions,real-time wireless underwater communication and other functions.First,according to the application scenario of the system,the overall parameters of the device are designed to determine the mode of modulation and demodulation.Then the OFDM demodulation method is easily affected by the frequency offset,and three kinds of Doppler compensation methods are selected and compared.Finally,the Doppler compensation method based on Chirp-z is selected as the compensation method for this system.Then introduced the specific circuit design of this set of equipment,including the collection of ocean hydrological data,timing start of communication function,OFDM signal sending and receiving functions.And on the DSP to achieve the corresponding hardware driver programming,for the characteristics of DSP serial instructions using EDMA data handling,improving the system's operating speed.Finally,in the laboratory,each functional part is independently verified and completed the hydrological data monitoring function and communication function detection of the entire equipment.Subsequently,a test was conducted in the channel pool to verify the overall function of the equipment and to ensure the use of the requirements by simulating the application scenarios of the marine ranch.