Underwater Acoustic Instruction Set Voice Communication System Based On ICore

With the rapid development of technology and civilization, human exploration and development of the living environment has gradually strengthened. More and more people are aware of that the sea, accounting for71%of the Earth’s marine area, will inevitably play an important role in the future. However, because of the restriction of the congenital conditions, humans are not able to complete voice communications under the water, can but rely on simple gestures to communicate. Therefore, this paper designed a set of underwater acoustic instruction set communication system to help auxiliary diver communicate with each other. This system has high practical value.In order to improve the capability of anti-jamming and anti weakness of the system, this paper use frequency hopping&spread spectrum technology, combined with Multiple Frequency Shift Keying (MFSK) technology as system design approach, which is commonly used in modern digital underwater communication systems. In transmit frame synchronization structure design, the synchronization acquisition module proposes a Goertzel algorithm to achieve real-time spectral analysis. Meanwhile, with the method of slope elimination, Chirp signal is used as frame synchronization to correct the synchronization error. FFT spectrum analysis of the data demodulation is achieved by using the STM32DSP library.The main work of the paper is completed the design of a set of acoustic communication system and achieved reliable underwater transmission of text instructions based on STM32after demonstrating the system-related key communications technologies. This paper made a detailed introduction of the design process and the implementation of each functional module. This system uses iCore, including STM32as main control chip and FPGA as coprocessor, to complete the main part of the system hardware, integrates speech recognition and synthesis module LD3320, amplifier circuit, filter circuit, automatic gain control circuit, through rational design, reach the goal of miniaturization and practicability.At the end of the paper, this underwater acoustic instruction transmission system has been tested by anti-noise experiments and pool multipath experiments. The experimental results show that the system is able to achieve stable and reliable communication under the conditions of low signal-to-noise ratio and strong multipath.