复合抛物面聚光器作为可见光通信光学天线的设计研究与性能分析

针对室内可见光通信的特点, 选择复合抛物面聚光器作为可见光通信系统光学天线, 介绍了复合抛物面聚光器的几何结构和光学特性, 利用光学仿真软件 TracePro对复合抛物面聚光器进行了设计、建模与仿真. 通过对不同光源条件下复合抛物面聚光器聚光特性的仿真发现: 在光源为朗伯辐射模型时复合抛物面聚光器的聚光性能更好, 且视场角越小增益越高; 但接收端与光源的相对位置对小视场复合抛物面聚光器的实际增益有明显影响, 在仿真条件下, 视场角为10°的复合抛物面聚光器实际增益为22.88, 比理论值降低了31%. 在此基础上, 在一个5 m×5 m×3 m的房间中对采用复合抛物面聚光器为光学天线的室内可见光通信系统进行了建模, 分别得到了直射链路和非直射链路下房间内各个位置的光功率分布. 仿真结果表明, 采用一个视场角为60°的复合抛物面聚光器为光学天线, 两种链路下平均接收功率分别提高了4.29 dBm和4.77 dBm, 非直射链路比直射链路的平均接收功率提高了11.2%.

Design research and performance analysis of compound parabolic concentrators as optical antennas in visible light communication

In order to satisfy the need of visible light communication, compound parabolic concentrators are selected as the optical antennas because of their wide fields of view and high gains in small field of view. Their geometries and optical properties are introduced in order to design compound parabolic concentrators with different fields of view by TracePro. These compound parabolic concentrators are tested under different light source conditions. The distribution of the received power of the receiver which has been coupled with the compound parabolic concentrator, is obtained by a simulation. The obtained gain of compound parabolic concentrator proves that the compound parabolic concentrator works better when the light source has a Lambert radiation pattern than the case under a parallel light condition. The results illustrate that compound parabolic concentrator is suitable to serving as an optical antenna for visible light communication. And it also shows that the smaller the field of view, the greater the gain is. Under the condition of simulation in this paper, a compound parabolic concentrator with 10° field of view could realize a gain of 22.88, which is 31% lower than the theoretical gain because of the effect of its position relative to the light source. On this basis, the model of a visible light communication system is established in a room with a size of 5 m×5 m×3 m. By using a compound parabolic concentrator with a field of view of 60° as an optical antenna, the simulation results show that the average received power is increased by 4.29 dBm for the directed light from light emitting diodes, and by 4.77 dBm with the reflected light being included. And the average received power is increased by 11.2% when the reflected light is considered.