二级级联式室内可见光通信光学接收天线设计

Design of two-cascade optical antenna for indoor visible light communication

针对室内可见光通信系统的传统光学接收天线无法同时满足高增益和大视场的问题,设计了一种二级级联式光学天线.通过分析信噪比、通信速率与接收天线视场角的关系,发现视场角为40?—60?的光学天线最适用于室内可见光通信系统.通过光学仿真软件Trace Pro的模拟及计算,给出了所设计的二级级联式光学天线的增益随信号光入射角的变化关系.结果表明,相较于传统接收天线,二级级联式光学天线具有更好的光学性能,视场角为菲涅耳透镜单独接收时的4倍.利用Matlab对二级级联式光学天线竖直向上时的接收功率分布进行仿真,结果显示探测器接收到的信号功率提升效果明显,平均值较直接探测时增大了7 d Bm,进一步证实该二级级联式光学天线适用于室内可见光通信系统.

White light emitting diode （LED） is expected to replace the incandescent lamp and becomes the next generation of lighting source because of its long life expectancy, high tolerance to humidity, and low power consumption. It is proposed that for the indoor visible light communication system white LED should be used as both lighting source and base station for its properties of high brightness and high speed modulation. Indoor visible light communication has a very wide area of applications, but there is a lack of research on receiver optical antenna that functions as an energy concentrator so as to increase received power. In order to meet the needs of high gain and meanwhile large field of view of receiver optical antenna for indoor visible light communication, two-cascade optical antenna is designed. It is shown that the field of view from 40 to 60 degrees can meet the requirements for high speed communication by analyzing the relationship between signal-to-noise ratio and data rate of different fields of view. The performances of the traditional optical antenna of Fresnel lens and the compound parabolic concentrator are simulated and analyzed by TacrePro. The gains of the designed two-cascade optical antenna are discussed at different incident angles. The results show that two- cascade optical antenna has better performance than traditional receiver optical antenna. The distribution of received power of two-cascade optical antenna is analyzed by using Matlab. The received average power by using two-cascade optical antenna is about 7 dBm larger than that without any optical antenna. The designed optical antenna provides a field of view of 40 degrees and enough gain for indoor visible light communication system.