Abstract In this work, we investigate a LUT-based digital predistortion technique applied to a Visible Light Communication system. We study the performance of the predistortion technique for OFDM signals with up to 2048 subcarriers, 16-QAM modulation, and three levels of DC bias considering the voltage–current LED response of a commercially available device. In addition, we propose a new and simpler pilot-assisted approach for the OFDM channel estimation, named Constant Response Window, the performance being tested with up to 64-QAM modulation and 2048 IFFT size OFDM signals. BER and MSE results show that the combination of the LUT-based digital predistortion technique with the new estimation method presents an improved performance over the Least Squares and the Minimum Mean Square Error channel estimation techniques in the considered scenario.

中文翻译：

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应用于OFDM VLC链路的恒定响应窗口信道估计方法和基于LUT的数字预失真

摘要 在这项工作中，我们研究了一种应用于可见光通信系统的基于 LUT 的数字预失真技术。考虑到商用设备的电压-电流 LED 响应，我们研究了预失真技术对具有多达 2048 个子载波、16-QAM 调制和三个直流偏置电平的 OFDM 信号的性能。此外，我们为 OFDM 信道估计提出了一种新的、更简单的导频辅助方法，称为恒定响应窗口，使用高达 64-QAM 调制和 2048 IFFT 大小的 OFDM 信号测试性能。BER 和 MSE 结果表明，在所考虑的场景中，基于 LUT 的数字预失真技术与新估计方法的组合比最小二乘法和最小均方误差信道估计技术具有更高的性能。