Design,Simulation And Experimental Study Of A Solar Blind Ultraviolet Video Transmission System Based On FPGA

The ultraviolet communication is based on atmospheric scattering and has the advantages of high security,anti-interference,all-time and a certain degree of NLOS communication.It has a bright future in military applications,so it has attracted more and more attention from researchers.However,the current UV communication system has low transmission speed and short communication distance,which limits its practical application.Considering the slow communication rate,this paper utilizes LED as the launching light source,and designs high-speed transceiver circuits,thereby improving the communication speed of the system.On this basis,a solar blind ultraviolet LED video communication system is designed and investigated based on the FPGA.The main research work of this paper is as follows:Firstly,the basic principle of atmospheric ultraviolet communication is analyzed,and the scattering,absorption and turbulence effects of ultraviolet light are discussed.The transmittance of ultraviolet light in different gases,altitudes,transmission distances and weather conditions is simulated by Modtran.Secondly,the different devices and modulation modes of the system are compared and analyzed.Considering the slow modulation rate and large volume of the gas lamp and the laser,and the high working voltage of the photomultiplier tube(PMT),a single LED with a central wavelength of 265 nm and the UV PIN detector are adopted in the system.In order to improve the bandwidth utilization,the system chooses OOK modulation and demodulation mode.Thirdly,in the circuit design,the traditional LED drive circuit used triode is improved by the characteristics of the operational amplifier comparator,and the bandwidth characteristics of the transmitting circuit are improved.The series impedance amplifier circuit is designed at the receiver.In the aspect of antenna design,three different collimation methods of lens group,parabolic reflector cup and single lens are simulated by ZEMAX,and the collimation method of single lens is adopted in the end.In the aspect of FPGA code module design,the design idea of each module is discussed in detail,and the structure diagram of transceiver module is given.Finally,the solar blind ultraviolet video communication system is built,and the bandwidth characteristic of ELD is tested.The relationship between the optical power density and the communication distance of the LOS communication system is studied.In the end,when the communication distance is 4m,the system can transmit video at a speed of 10 fps,with a communication rate of 1.92Mbit/s,which is higher than the results reported in the current literature.