Research On Underwater Acoustic Communication Transmitter Based On FPGA

In recent years,many countries have paid great attention to the development of marine resources all over the world.They are constantly strengthening the marine development strategy,and using high technology to develop and manage the ocean.In the development of marine resources,information transmission and processing are inevitable,and underwater acoustic communication technology has become the main means of underwater information transmission.In order to meet the requirements of high efficiency and small volume of underwater acoustic communication system,this paper designs and implements an underwater acoustic communication transmitter based on FPGA.Firstly,this paper expounds the background and significance of underwater acoustic communication,as well as the characteristics,structure and design scheme of underwater acoustic communication transmitter.Secondly,combined with the channel characteristics of underwater acoustic communication and the functional requirements of anti-interference,this paper analyzes digital modulation technology and the principle of carrier signal generation.We mainly focuse on the digital modulation schemes of 2FSK and MFSK.The digital modulation unit based on FPGA and DDS technology is designed and implemented.Then the circuit structure and principle of the power amplifier are analyzed,and select a Class D amplifier suitable for underwater acoustic communication according to the characteristics of the transducer.Study the PWM modulation technology of digital power amplifier,and perform FPGA-based programming simulation on the modulation method;Designing a power amplifier circuit and its peripheral circuits using an IRS2092 S power amplifier chip that integrates PWM modulation and driving.In order to achieve maximum power transmission,this paper designs and optimizes the impedance matching circuit between the power amplifier.Finally,the performance test of the underwater acoustic communication transmitter designed and manufactured in this paper is carried out.The return loss value of the transducer connected to the matching circuit is measured by the handheld network analyzer,and the output power of the system is observed through the DC power supply.The underwater acoustic communication transmitter designed in this paper mainly includes three parts: FPGA-based digital modulation unit module,class D power amplifier module and transducer matching circuit.After the design is completed,the performance of the underwater acoustic communication transmitter is tested.The test results show that the underwater acoustic communication transmitter meets the design specifications and achieves the expected goal.