Design And Implementation Of Underwater Acoustic Communication Transmitter Based On SoC FPGA

The exploration and development of the Arctic region is one of the focuses of the marine strategic layout in our country,and underwater acoustic communication is the most important means to realize the integrated information perception and information interaction between the Arctic subglacial and underwater.Acoustic transmitters,as an essential part of underwater acoustic communication system,have great influence on the whole underwater acoustic communication system.In order to meet the demand of small volume and different forms of signals for underwater acoustic communications under ice,a SoC FPGA-based underwater acoustic communication transmitter was designed and implemented.The transmitter designed in this paper is composed of a signal generating circuit,a power amplifier and a transducer impedance matching.The signal generation circuit is built around the SoC FPGA,and the ARM core in the SoC is used as a master to process and store the data sent by the host computer through the network port.The AXI bus in SoC chip are used to transfer the data from HPS to FPGA.The power amplifier uses digital D power amplifier,The SPWM modulation and ?-?modulation of class D power amplifier are simulated and analyzed.Several sampling methods of SPWM modulation are analyzed.The midpoint sampling output of SPWM modulation of signal is realized by using FPGA in SoC.The hardware circuit of class D power amplifier is designed.An optical coupling circuit is added between the signal generating circuit and the power amplifier to reduce mutual interference of the digital circuit and the analog circuit.The driving stage of the power amplifier uses IR2110 S chip to drive the MOSFET.A matching circuit is added between the power amplifier and the transducer for impedance matching of the transducer.In this paper,the basic modulation methods of digital communication are introduced,and the communication signals such as LFM 2FSK BPSK and QPSK are researched and simulated.In the pool,the sound source level of the transmitter was first tested with a standard hydrophone.The sound source level of the transmitter is greater than or equal to180 dB in the operating frequency range of 8kHz-16 kHz,meeting the design requirements.Then,the transmitter was used to transmit the simulated test signals BPSK and QPSK.The received signal was received by hydrophone,and the received signal was processed and analyzed.The experimental results verify that the designed underwater acoustic communication transmitter can meet the basic requirements of underwater acoustic communication.