Adaptive equalization system for visible light wireless communication utilizing multiple white LED lighting equipment
Adaptive equalization system for visible light wireless communication utilizing multiple white LED lighting equipment
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DOI：
10.1109/twc.2009.060258
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发表时间：
2009-06
影响因子：
10.4
通讯作者：
T. Komine;Junhwan Lee;S. Haruyama;M. Nakagawa
中科院分区：
文献类型：
--
作者：
T. Komine;Junhwan Lee;S. Haruyama;M. Nakagawa
白光 LED 发明于 20 世纪 90 年代。从那时起，它们就以各种方式得到了广泛的研究和应用。与传统照明装置相比，白光LED具有更低的功耗、更低的电压要求、更长的寿命、更小的尺寸、更快的响应速度以及更低的工作温度。白光 LED 最终将取代办公室和家庭中的白炽灯或荧光灯。我们提出了一种利用多个白光 LED 照明设备的室内可见光无线通信系统。在该系统中，该设备不仅用于房间照明，还用于光无线通信系统。该系统的功率水平明显高于红外无线通信系统，因为它还充当主要照明设备。一个问题是我们倾向于在天花板上安装许多光源，以便尽可能均匀地照亮房间。虽然源的数量允许通过 LOS 链路进行站点分集传输，但多个源之间的光程差会触发码间干扰 (ISI)，从而显着降低系统性能。本文通过提出自适应均衡系统来克服 ISI 问题。我们阐明了移动环境中信道估计的最有效的训练序列间隔。我们证明了具有有效间隔的自适应均衡系统减轻了阴影的影响。
White LEDs were invented the 1990's. Since then they have been extensively researched and applied in various ways. Compared with conventional lighting devices, the white LED has lower power consumption, lower voltage requirements, longer lifetime, smaller size, faster response, and cooler operation. The white LED will eventually replace incandescent or fluorescent lights in offices and homes. We have proposed an indoor visible light wireless communication system that utilizes multiple white LED lighting equipment. In this system, the equipment is used not only for illuminating rooms but also for an optical wireless communication system. The system has significantly higher power levels than infrared wireless communication systems, since it also functions as the main lighting equipment. One problem is we tend to install many lighting sources on a ceiling in order to illuminate the room as evenly as possible. While the number of sources permits site diversity transmission over LOS links, the optical path difference between the multiple sources triggers intersymbol interference (ISI), which significantly degrades system performance. This paper overcomes the ISI problem by proposing an adaptive equalization system. We elucidate the most effective training sequence interval for channel estimation in a mobile environment. And we show that the adaptive equalization system with the effectual interval alleviates the influence of shadowing.