The Design And Implementation Of UV-Scattering Communication System Based On STM32 Microcontroller

Ultraviolet Optics Speech Communication is a new type communication system in free space optics communication fields. Its excellent performances such as safety, anti-interference,Non Line-of-Sight, make it different from infrared optics and RF communication. Hence, ultraviolet optics communication gratifies the need of special and confidential communication in army.The short-range, non-line-of-sight(NLOS) ultraviolet communications relies upon two related phenomena. The first is that atmospheric gases, particularly ozone and oxygen,are strong absorbers of light in the spectral region between 200nm to 280nm which is called "Solar-Blind Region",so that the solar radiation reaching the ground in this waveband is negligible. The second is that solar-blind UV generated at the earth's surface is strongly scattered.According to the ultraviolet light characteristics,some important devices are discussed and selected.For some superiorities such as high transforming efficiency, wide range power,excellent spectral line performance,the low voltage mercury lamp is used. To make the right modulation scheme,the low voltage mercury lamp's lighting principle andⅤ-Ⅰcharactericstics are discussed,and also considering the baseband signal is a binary style,the 2FSK-modulation modle is selected finally. Last, considering the low transmission speed of the communication system, in order to relize speech communication, we raise a speech coding method based on the chip of CMX638. The entire system to deal with STM32 as the microcontroller chip and the photomultiplier tubes MP922 for the UV detector, starting from the UV atmospheric model analysis, realize information transmission in the lab.