摘要
利用单个照明灯具内多个LED灯芯,在不同驱动电压条件同时并行发送不同数据,经过可见光信道叠加传输数据后,接收端由单一PD检测汇聚的多路光强信号,再按照各个灯芯驱动电压差异检测恢复出各个灯芯的数据,从而实现数据成倍的高速传输。针对叠加传输中LED驱动电压非负特性,提出了基于开关键控OOK调制的接收端检测算法,在此基础上提出了针对LED电光转换非线性的信噪比演进和规划的联合功率分配方案。仿真表明该方案在牺牲一定信噪比的条件下使叠加高速通信中LED的驱动电压工作在线性范围内,并且获得和未规划时相同的误比特率性能;与低码率的多灯芯恒定驱动电压方案相比,该方案传输效率更高。
Multiple LED wicks are used in a single lamp to send disparate data under different driving voltages at the same time. At the receiver, a single photodiode（PD） is used to detect the convergence light intensity signals after superposition transmission in visible light channel. Finally, data can be detected and separated by the divergence of driving voltages. Thus the data rate that is multiple times of a single LED wick can be realized. Due to the nonnegative characteristics of LED driving voltage, the detecting algorithm of the receiver based on on-off keying （OOK） modulation is proposed. Meanwhile, joint power allocation scheme of the Signal to noise ratio（SNR） evolution and programing for the electro-optical conversion nonlinearity of LED are proposed. The simulation shows that sacrifice in SNR could make LED work within the linear range of superposition high-speed communication. And the system could achieve the same bit error rate（BER） performance as the un-programming scheme. Comparing with the low-rate scheme under the constant driving voltage of multiple LED wicks, the proposed scheme is more efficient.
出处
《信号处理》
CSCD
北大核心
2014年第9期1078-1085,共8页
Journal of Signal Processing
基金
国家863高技术研究发展计划项目(2013AA013603)
国家自然科学基金(61271253)
关键词
可见光通信
功率分配
叠加高速传输
信噪比演进
电光转换非线性
visible light communications
power allocation
superimposed high-speed communication
signal-to-noise evolution
electro-to-optical conversion nonlinearity
