Alignment difficulty in free space optical communication is significantly reduced by ultraviolet communication. The problem of unclear propagation characteristics of ultraviolet light in the atmosphere is addressed. Simulations based on the Monte Carlo method were conducted. A real-time UVC (ultraviolet C radiation) system was proposed and designed. Real-time signal processing algorithms for transmission and reception were designed using a FPGA (field-programmable gate array). Ultraviolet light of multiple wavelengths was emitted by Light Emitting Diodes. Optical signals were received by a Photomultiplier Tube. Significant differences in atmospheric attenuation characteristics for different wavelengths are shown by the experimental results. Communication performance is directly affected by these differences. A small BER(bit error rate ) difference between 250 nm and 300 nm systems is observed at a communication distance of less than 60 meters. At a distance of 100 meters, a BER of approximately 10-4 is exhibited by the 300 nm system. A BER of approximately 10-2 is exhibited by the 250 nm system. At a distance of 120 meters, no photons are detected in the 250 nm system. A small number of photons are still detected by the Photomultiplier Tube in the 300 nm system. Lower attenuation and stronger transmission capability are indicated by the UVC system with a longer wavelength.