一种室内可见光通信亮度控制方法  

A brightness control method for indoor visible light communications

作　　者：张建昆[1] 刘博[1] 杨宇[1] 陈雄斌[1] 陈弘达[1] 

机构地区：[1]中国科学院半导体研究所,集成光电子学国家重点联合实验室,北京100083

出　　处：《光电子．激光》2011年第7期1013-1017,共5页Journal of Optoelectronics·Laser

基　　金：国家科技支撑资助项目(2009BAK43B36);中国科学院知识创新工程重要方向性资助项目(2006A10401006)

摘　　要：为了解决室内无线可见光通信中照明光源亮度不稳定的问题,提出了一种新型的以脉冲宽度调制（PWM）波形作为载波的编码调制方法,设计了基于该方法的发射器和接收器。PWM波形在逻辑1和逻辑0时的载波占空比相同,频率分别为38 kHz和7 kHz。发射端采用高亮度白光LED作为光源,接收端采用PIN光电二极管和低噪声放大器作为前置放大器部分。PWM波形的生成、编码与解码,分别通过发射和接收端的微控制器实现。实验结果表明,使用PWM波形作为载波的编码调制方法可以控制光源亮度变化范围达1.5~98.5%,占空比下降到6%时接收的电压信号强度仅下降18%,光源亮度稳定,满足可见光通信光源亮度稳定、可调的要求。In order to solve the problem of instability of illumination brightness in visible light communications,a novel coding modulation method using pulse width modulation（PWM） waveform as carrier is proposed.A transmitting and receiving module based on this method is designed.The frequencies of PWM waveform at logic 1 and logic 0 are 38 kHz and 7 kHz,respectively.A high brightness light-emitting diode（LED） was used as source,a current input preamplifier composed of a PIN photodiode and low a noise wide-bandwidth amplifier was designed in the receiver module,and the encoding and decoding were implemented by micro-controller.Experimental results indicate that the brightness will range from 0% to 100% using the PWM waveform coding modulation method,and when the PWM waveform duty cycle is below 6%,the received voltage only decreases by 18%,and the illumination brightness is stable.It can satisfy the system requirements of adjustability and stability of for the illumination brightness.

关 键 词：可见光通信 室内照明 脉冲编码调制(PWM) 亮度控制 高亮度白光LED 

分 类 号：TN929.12[电子电信—通信与信息系统]