Design of underwater long-distance communication system based on blue LED

In order to meet the communication requirements of underwater long-distance, high-speed, low-error code and high-performance communication, this paper designs a low-power, miniaturized underwater wireless optical communication system. The blue LED array is used as the light source to improve the output power and increase the transmitting angle of view, the photomultiplier tube (PMT) is used as the detector to greatly improve the receiving gain, the whole transceiver system is based on FPGA to realize the RS coding and decoding of the data, while adding 8B/10B coding to solve the equalization problem of OOK modulation, the internal circuit optimization process to improve the overall performance of the system, and the external structure design controls the transceiver perspective, which improves the energy transmission efficiency of the system. After the pool experimental test, the system can realize stable communication with underwater distance of 50 m, communication rate of 100 kb/s and bit error rate (BER) lower than 10^-6, which lays a foundation for the development of underwater long-distance wireless optical communication.