Indoor VLC system with multiple LEDs of different path lengths employing space-time block-coded DMT/CAP modulation [invited]
Indoor VLC system with multiple LEDs of different path lengths employing space-time block-coded DMT/CAP modulation [invited]
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DOI：
10.1364/jocn.7.00a459
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发表时间：
2015-03
期刊：
影响因子：
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通讯作者：
Chia-Chien Wei;Fang-Ming Wu;Zhen-Yu Chen;Chun-Ting Lin;Yu-Syuan Huang;Yung-Jui Chen;S. Chi
中科院分区：
文献类型：
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作者：
Chia-Chien Wei;Fang-Ming Wu;Zhen-Yu Chen;Chun-Ting Lin;Yu-Syuan Huang;Yung-Jui Chen;S. Chi
我们实验证明了一个实用的可见光通信(VLC)系统，使用频谱高效的离散多音(DMT)或无载波幅度相位(CAP)调制传输3.2m。发射器由两个相距2m的发光二极管(LED)组成，其布置对应于室内环境中全范围照明的常见情况，本工作还研究了从LED到单个接收器的传输路径长度差异的影响。在重叠照明区域中，当两个LED简单地传输相同的信号时，使用四元CAP或位加载的DMT信号，LED之间的延迟干扰可以导致高达约40%的容量减少。为了减小时延干扰的影响，对DMT和CAP信号都采用了Alamti空时分组编码(STBC)，并首次提出了CAP和STBC的组合。利用空时分组码，我们成功地展示了在3.2-m空中传输中的抗干扰性VLC，DMT和CAP信号的最大数据速率分别为220 Mbps和150 Mbps。
We experimentally demonstrate a practical visible light communication (VLC) system of 3.2-m transmission using spectrally efficient discrete multitone (DMT) or carrierless amplitude phase (CAP) modulation. The transmitters consist of two light emitting diodes (LEDs) spaced 2 m apart, the arrangement of which corresponds to a common case for full-range illumination in indoor environments, and this work also investigates the influence of the difference in transmission path lengths from the LEDs to a single receiver. In the overlapped illumination area, the delay interference between the LEDs could result in up to about 40% capacity reduction using quaternary CAP or bit-loaded DMT signals, when two LEDs simply transmit the same signal. To mitigate the impact of the delay interference, Alamouti space-time block coding (STBC) is employed for both DMT and CAP signals, and the combination of CAP and STBC is proposed for the first time to the authors' best knowledge. Employing STBC, we successfully demonstrate interference-tolerant VLC over 3.2-m air transmission, and the maximum data rates for DMT and CAP signals are 220 and 150 Mbps, respectively.