Research On The Implementation Of Low Cost Underwater Acoustic Modem

Underwater acoustic communication has a wide range of applications and important significance in both military and civilian fields.In the military field,underwater acoustic communication technology is an important means of underwater combat and marine intelligence collection.In the civilian field,underwater acoustic communication technology is widely used in marine scientific research,marine resource exploration,underwater detection,etc.,providing important support for marine development and scientific research.The research of this thesis is mainly applied in the civilian field.The high price of the existing commercial underwater acoustic communication system limits the application and development of the underwater acoustic communication technology in the civilian field.Based on this,a low-cost underwater acoustic communication system is proposed and designed in this thesis.The purpose is not to replace the current commercial underwater acoustic communication system,but to provide a new tool for low-cost underwater acoustic communication.Based on the design requirements of large-scale application in the civilian field,through the analysis of the design of the existing underwater acoustic communicator,the thesis first proposes the overall design scheme of the low-cost underwater acoustic communicator.The modular design is adopted in the design scheme,which can reduce the Equipment maintenance costs and equipment reliability are improved.At the same time,in order to be able to work in different environments,a programmable chip design is used to improve the adaptability of the equipment.Then in the hardware circuit design,the transmitter design using the full-bridge class D amplifier is completed,and the impedance matching network is studied,and the program-controlled gain and AD8338 automatic gain control(AGC)are used in the receiver to achieve a gain of 75 d B,and designed an 8-order bandpass filter.In the digital processing unit selection,IMXRT1060 was selected,and the 12-bit ADC integrated with IMXRT1060 was used for data acquisition,and the relevant data was stored through the SD card.Secondly,in the algorithm selection,according to the performance of the designed hardware circuit,the BFSK communication algorithm is selected,and the feasibility of the communication algorithm is verified through the AWGN channel.Finally,the designed underwater acoustic communicator is tested,including the automatic gain function test of the receiver,the sound source level test of the transmitter,the data acquisition function and data storage function test of the digital processing unit,and the laboratory communication test.After the above functional tests,it is proved that the underwater acoustic communicator designed in this thesis meets the design specifications,can realize stable underwater communication,and the overall cost is controllable,which meets the design requirements of practicability and low cost.In summary,the low-cost underwater acoustic communication system designed in this thesis has the advantages of low development and testing costs,high efficiency,and modularization,and is suitable for large-scale deployment in the ocean.Apps offer new possibilities.