Yang Yiting, He Jing, Zhou Biao
Appl Opt. 2021 Dec 10;60(35):10928-10934. doi: 10.1364/AO.443681.
Recently, optical camera communication (OCC) based on light-emitting diodes (LEDs) and complementary metal oxide semiconductor (CMOS) image sensors has received extensive attention due to its low cost and high flexibility. However, considering that the location of the user with a CMOS image sensor changes frequently, multi-LEDs are required to achieve seamless communication. In the paper, to mitigate random interchannel interference in overlapping areas of LED radiation, an effective identification recognition and sorting-based column selection are proposed. Meanwhile, to alleviate the distortion of bright and dark stripes caused by overlapping exposure time and user movement, an improved sampling scheme based on length estimation is proposed and experimentally demonstrated in a multi-LED-based mobile OCC system. Moreover, by varying the overlap rate of the adjacent LEDs' radiation area and the moving speed of the user, respectively, the performance of the system is investigated. The experimental results show that, the bit error rate (BER) performance of the system decreases slightly with the increasing of moving speed, but it is lower than the hard-decision forward error code rate limit. In addition, at the overlap rate of the LED radiation area of 4.3% and the moving speed of 80 cm/s, the BER is close to 10 using the proposed scheme.
近年来，基于发光二极管（LED）和互补金属氧化物半导体（CMOS）图像传感器的光学相机通信（OCC）因其低成本和高灵活性而受到广泛关注。然而，考虑到使用CMOS图像传感器的用户位置频繁变化，需要多个LED来实现无缝通信。在本文中，为了减轻LED辐射重叠区域中的随机信道间干扰，提出了一种基于有效识别和排序的列选择方法。同时，为了减轻由于重叠曝光时间和用户移动引起的明暗条纹失真，提出了一种基于长度估计的改进采样方案，并在基于多LED的移动OCC系统中进行了实验验证。此外，分别通过改变相邻LED辐射区域的重叠率和用户的移动速度，研究了系统的性能。实验结果表明，系统的误码率（BER）性能随着移动速度的增加略有下降，但低于硬判决前向纠错码率限制。此外，在LED辐射区域重叠率为4.3%且移动速度为80 cm/s时，使用所提出的方案，BER接近10。
