Yeh Chien-Hung, Chen Hsing-Yu, Chow Chi-Wai, Liu Yen-Liang
Opt Express. 2015 Jan 26;23(2):1133-8. doi: 10.1364/OE.23.001133.
To increase the traffic rate in phosphor-LED visible light communication (VLC), a multi-band orthogonal frequency division multiplexed (OFDM) modulation is first proposed and demonstrated. In the measurement, we do not utilize optical blue filter to increase modulation bandwidth of phosphor-LED in the VLC system. In this proposed scheme, different bands of OFDM signals are applied to different LED chips in a LED lamp, this can avoid the power fading and nonlinearity issue by applying the same OFDM signal to all the LED chips in a LED lamp. Here, the maximum increase percentages of traffic rates are 41.1%, 17.8% and 17.8% under received illuminations of 200, 500 and 1000 Lux, respectively, when the proposed three-band OFDM modulation is used in the VLC system. In addition, the analysis and verification by experiments are also performed.
为了提高磷光发光二极管可见光通信（VLC）中的通信速率，首次提出并演示了一种多频段正交频分复用（OFDM）调制方法。在测量过程中，我们未使用光学蓝光滤波器来增加VLC系统中磷光发光二极管的调制带宽。在该方案中，将不同频段的OFDM信号应用于LED灯中的不同LED芯片，这样可以避免将相同的OFDM信号应用于LED灯中的所有LED芯片时出现的功率衰落和非线性问题。在此，当在VLC系统中使用所提出的三频段OFDM调制时，在接收光照度分别为200勒克斯、500勒克斯和1000勒克斯的情况下，通信速率的最大增加百分比分别为41.1%、17.8%和17.8%。此外，还进行了实验分析与验证。
