Abstract Visible light communication (VLC) emerges as a promising candidate in vehicle-to-infrastructure (V2I) networks. For VLC downlink between street lamps and a mobile vehicle, received signals tend to experience a time-varying multi-source and multi-path channel condition. This will affect the effectiveness of channel equalization when assuming constant channel characteristics within each data packet. In this paper, in order to track the time-varying mobile VLC channel effectively, we propose a channel estimation method for V2I downlink based on decision feedback with orthogonal frequency division multiplexing. Considering different system parameters, extensive numerical experiments are carried out. Results show that compared with the conventional scheme using only training sequences, adopting decision feedback can achieve higher channel estimation accuracy, thus improving link performance significantly. For vehicle velocity at 15 m/s, bit error rate (BER) − 4 can be achieved at ∼ 199 Mbps if transmit power per lamp is > 30 W. Moreover, the proposed method is almost unaffected by the change of vehicle moving state, with stable BER achieved.

中文翻译：

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基于决策反馈的车辆到基础设施可见光通信系统中的移动信道估计

摘要 可见光通信 (VLC) 成为车辆到基础设施 (V2I) 网络中的一个有前途的候选者。对于路灯和移动车辆之间的 VLC 下行链路，接收到的信号往往会经历时变的多源和多径信道条件。当假设每个数据包内的信道特性恒定时，这将影响信道均衡的有效性。在本文中，为了有效跟踪时变移动VLC信道，我们提出了一种基于正交频分复用决策反馈的V2I下行信道估计方法。考虑到不同的系统参数，进行了大量的数值实验。结果表明，与仅使用训练序列的常规方案相比，采用决策反馈可以获得更高的信道估计精度，从而显着提高链路性能。对于 15 m/s 的车辆速度，如果每盏灯的发射功率 > 30 W，则误码率 (BER) − 4 可以达到 ~ 199 Mbps。 此外，所提出的方法几乎不受车辆运动状态变化的影响，实现稳定的 BER。