室外可见光通信接收端光学去噪技术研究

发布时间：2018-04-26 21:34

本文选题：可见光通信 + 光学滤波　；参考：《江苏大学》2016年硕士论文

【摘要】：LED可见光无线通信因绿色低碳、低能耗、无电磁干扰等特点,成为了一种新型的通信方式,并逐步应用在LED照明设备上。如今LED光源已经被广泛应用于汽车前照灯、交通信号灯、路灯等设备上,使可见光无线通信应用到智能交通系统和车联网中成为可能。室外可见光通信受到自然光和不同天气情况的严重影响,从而导致接收端性能的下降。在本文研究的室外可见光通信系统中,使用汽车LED前照灯作为信号的发射源,近地面空气作为传输信道。针对接收端所受到的自然光背景噪声,采用光学滤波技术进行处理,设计了诱导透射滤光片、光角度选择器,使室外可见光通信系统的通信质量得到提高。论文主要完成的工作和创新点:(1)为了有效滤除太阳光噪声,设计了一种新型带通滤光片。对汽车LED前照灯光谱和太阳光光谱进行分析,根据汽车LED前照灯光谱与太阳光光谱之间的重叠和非重叠区域,确定了滤波通带的频谱形状。针对此通带的频谱形状,采用诱导透射滤光片进行滤波。根据光学薄膜计算方法设计了诱导透射滤光片的膜系结构参数,并对所设计的膜系通带进行仿真。在保障信号光顺利通过的情况下,实现了对太阳光噪声的有效滤除。对诱导透射滤光片进行性能分析,结果表明使用诱导透射滤光片后系统信噪比提高了1.44倍。(2)设计了光角度选择器,以保证信号光和自然光的最佳入射角。对汽车LED信号光入射角与滤光片通带形状的关系和太阳光入射角与太阳光噪声功率的关系进行分析,确定汽车LED信号光的最佳入射角为0~10°,太阳光的最佳入射角为0~20°,设计了由阻断层、吸收层、透射层构成的汽车LED信号光光角度选择器和太阳光光角度选择器,保障了诱导透射滤光片通带形变程度最小,滤光效果最好并有效减少了太阳光噪声。(3)完成了光接收器的整体结构设计。光接收器分别由太阳光光角度选择器、汽车LED信号光光角度选择器、诱导透射滤光片、复合抛物面聚光器(CPC)、硅光电二极管组成。对接收器性能进行仿真分析。结果表明,在使用光接收器后不仅提高了接收端的的通信质量,而且提高了通信的有效距离。
[Abstract]:LED visible light wireless communication has become a new communication mode because of its green low carbon, low energy consumption and no electromagnetic interference, and has been gradually applied to LED lighting equipment. Nowadays, LED light source has been widely used in automotive headlights, traffic lights, street lights and other devices, making it possible to apply wireless communication of visible light to intelligent transportation systems and vehicle networking. Outdoor visible light communication is seriously affected by natural light and different weather conditions, which results in the degradation of receiver performance. In the outdoor visible light communication system studied in this paper, the vehicle LED headlamp is used as the source of signal transmission, and the near-ground air is used as the transmission channel. In view of the natural light background noise at the receiving end, the optical filtering technique is used to deal with the noise. The induced transmission filter and the optical angle selector are designed to improve the communication quality of the outdoor visible light communication system. In order to effectively filter the solar noise, a new band-pass filter is designed. The spectrum of automobile LED headlamp and the spectrum of solar light are analyzed. According to the overlapping and non-overlapping region between the spectrum of automotive LED headlamp and the spectrum of solar light, the spectrum shape of filter passband is determined. According to the spectrum shape of the passband, the induced transmission filter is used to filter. According to the optical thin film calculation method, the structure parameters of the membrane system of the induced transmission filter are designed, and the simulation of the pass band of the film system is carried out. In the case of ensuring the smooth passage of signal light, the effective filtering of solar light noise is realized. The performance of the induced transmission filter is analyzed. The results show that the signal-to-noise ratio (SNR) of the system is improved by 1.44 times by using the inductive transmission filter. (2) the optical angle selector is designed to ensure the optimum incident angle between the signal light and the natural light. The relationship between the incident angle of automobile LED signal and the shape of the pass band of the filter and the relation between the incidence angle of the solar light and the noise power of the solar light are analyzed. The optimum incidence angle of automobile LED signal light is determined to be 0 ~ 10 掳, and the optimum incidence angle of solar light is 0 ~ 20 掳. A car LED signal light angle selector and a solar light angle selector composed of blocking layer, absorption layer and transmission layer are designed. It ensures the minimum band deformation of the induced transmission filter, the best filtering effect and the effective reduction of the solar noise. 3) the overall structure design of the optical receiver is completed. The optical receiver consists of a solar angle selector, an automobile LED signal optical angle selector, a induced transmission filter, a composite parabolic concentrator, and a silicon photodiode. The performance of the receiver is simulated and analyzed. The results show that the optical receiver not only improves the communication quality of the receiver, but also improves the effective distance of the communication.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.1

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