In order to reduce the quantization noise of low-resolution DAC, we study a noise shaping technique that can reshape the white quantization noise to an irregular spectrum, in which the noise in the data subcarrier band is almost transformed into the null subcarrier band. Both in simulation and experiment, we verify the effectiveness of the investigated scheme in 25 GHz 16-QAM/32-QAM/64-QAM DMT transmission systems. The experimental results show that the noise shaping technique can enhance the receiver sensitivity of 4-bit quantized 16-QAM DMT and 5-bit quantized 32-QAM DMT by 4.3 dB and 2.5 dB respectively, at BER of hard decision forward error correction (HD-FEC) threshold (3.8 × 10 ⁻³ ). In addition, with the aid of noise shaping, the performance of 4-bit quantization 16-QAM DMT system is the same as the 8-bit quantization 16-QAM DMT system at the HD-FEC threshold. The experimental results reveal that the proposed noise shaping scheme is a good solution for high-speed, low-cost short reach intra-DCI with low-resolution DAC in future 6G networks evolved from 5G mobile networks.

中文翻译：

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利用低分辨率 DAC 的噪声整形增强型 DMT 信号传输

为了降低低分辨率DAC的量化噪声，我们研究了一种噪声整形技术，可以将白量化噪声重塑为不规则频谱，其中数据子载波带中的噪声几乎转化为空子载波带。在仿真和实验中，我们验证了所研究方案在 25 GHz 16-QAM/32-QAM/64-QAM DMT 传输系统中的有效性。实验结果表明，在硬判决前向纠错（HD -FEC) 阈值 (3.8 × 10 ⁻³ ）。此外，在噪声整形的帮助下，4位量化16-QAM DMT系统在HD-FEC门限上的性能与8位量化16-QAM DMT系统相同。实验结果表明，在从 5G 移动网络演进的未来 6G 网络中，所提出的噪声整形方案是具有低分辨率 DAC 的高速、低成本短距离内 DCI 的良好解决方案。