Research Optical Antenna In LED Light Communication System Based On CPC

LED visible light communication (VLC-LED) is an LED-based lighting emerging wireless optical communication technology, which the receiving system take the role of detecting, receiving, amplifying and processing signal, but the big angle light illuminating of LED is not easy to receive, the spreading light when they receive to receiving system has attenuated very serious, so the optical antenna needs to be placed in front of the detector in order to achieve convergence of light, enhance the role of the received signal. Paper studied the optical antenna based on compound parabolic concentrator (CPC), the main contents are as follows:(1) According to the needs of indoor lighting illumination inside the room, design 4×64 LED light source layout in the 4.0m×4.0m×2.8m room, so that the light intensity distribution of detection plane is 198.8?360.51x.(2) Simulation results of the CPC show that:CPC of the maximum collection angle of 40°, the exit radius of 1mm, the incident radius of 1.556mm, the focal length of 1.643mm, the length of 3.046mm on the detector plane, which make the amplification gain of direct light is 0.5817?1.3585db, having enhance the role of the signal.(3) Starting from the point of illumination to study the CPC to overcome the effects of multipath effects. The simulation results show that:After CPC concentrated, the illumination of the main-light source received increased 1.3985?1.5690db, the illumination of second-light source received increased -0.8459?1.2673db, but the increase in the positive light illumination times are some specific points that are substantially equal distance from each source, the actual multipath effects caused by positive increasing is not strong like description of data. After CPC concentrated, the illumination of the directing light increases 0.5817?1.3585db, the illumination of the reflecting light decreases 0.046?0.567db. Therefore, the main-light source and the directing light energy received by the detector concentrating, while the second-light source and the reflecting light energy is reduced, so that CPC has role in overcoming multipath effects.(4) CPC condensing the light, the illumination distribution of light energy is uneven, so the optical system is designed in combination the Fresnel lens with CPC, on the basis of without changing the converging angle, a slight decreasing of the light reception efficiency, but the light energy distribution with good uniformity has improved.Paper designs the combination optical system of Fresnel lens with CPC, which has a small volume, big concentrating ratio, simple structure, easy to install etc., and its research methodology of optical antenna also provides a new way to solve such problems.