Layered Transmission of Space-Time Coded Signals for Image-Sensor-Based Visible Light Communications
Layered Transmission of Space-Time Coded Signals for Image-Sensor-Based Visible Light Communications
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DOI：
10.1109/jlt.2015.2470091
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发表时间：
2015-10
影响因子：
4.7
通讯作者：
Katsunori Ebihara;K. Kamakura;T. Yamazato
中科院分区：
文献类型：
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作者：
Katsunori Ebihara;K. Kamakura;T. Yamazato
本文演示了分层空时编码（STC）在基于室外图像传感器（ISbased）可见光通信（VLC）系统中的可行性。我们检查了基于 IS 的低分辨率 VLC 通道，其中 IS 的一个像素检测到来自两个不同发光二极管 (LED) 的强度调制信号，STC 允许我们将它们解耦；因此，成功地接收了它们，没有错误。因此，STC 为像素分辨率有限的基于 IS 的 VLC 链路提供了更长的传输距离。在本文提出的分层 STC 中，在 2n × 2n LED 阵列上放置了额外的比特流，以在提高像素分辨率的情况下提高每个符号持续时间的传输速率。三层 STC 原型采用 8 × 8 LED 阵列构建，其中每个 LED 均以 1 kb/s 的速率进行调制，并配备 IS 运行速度为 1000 fps 的高速相机。我们的实验结果验证了当接收器分别位于距离 LED 阵列 155 和 55 m 的范围内时，在第 1 层 STC 矩阵对中对齐的两个附加比特流（第 2 层和第 -3 层）可以正确提取，并且不会减少第 1 层比特流的传输距离 210 m。
This paper demonstrates the feasibility of layered space-time coding (STC) in an outdoor image-sensor-based (ISbased) visible light communication (VLC) system. We examined that for low-resolution IS-based VLC channel where intensity-modulated signals from two different light emitting diodes (LEDs) are detected by one pixel of an IS, STC allows us to decouple them; thus, succeeding to receive them with no errors. Consequently, STC offers extended transmission distance to pixel-resolution-limited IS-based VLC links. In the layered STC presented in this paper, additional bit streams are laid on the 2n × 2n LED array for increasing the transmission rate per symbol duration for the case where the pixel resolution is improved. A prototype of a threelayered STC is built with an 8 × 8 LED array, where each of the LEDs is modulated at 1 kb/s and a high-speed camera with IS operating at 1000 fps. Our experimental results validate that the two additional bit streams (layer-2 and -3), aligned in the layer-1 STC matrix pair, are extracted with no errors when the receiver comes within 155 and 55 m, respectively, from the LED array, without decreasing 210 m of the transmission distance of layer-1 bit stream.