高速相干光OFDM通信系统基于Viterbi算法最大似然序列检测的噪声补偿算法研究

Coherent optical communication system has become the key solution to meet the increasing demand of bandwidth for Internet and civil communication. Due to its advantage of low loss, high safety and high bandwidth usage efficiency, coherent OFDM technology has drawn attention both domestically and internationally. Using small and low-cost digital signal processing (DSP) chips for noise compensation is of great strategic importance and value of research.. With the help of work on noise compensation algorithms in coherent OFDM systems, this project is aimed to independently develop a Viterbi-based maximum likelihood sequence detection algorithm for channel distortion compensation, especially phase noise compensation. Because it jointly uses the information of the whole sequence, the tolerance of noise is significantly improved. The Viterbi mechanism tremendously decreases the computational complexity of the coherent receiver. Moreover, the adaptive filter can automatically adjust itself to achieve optimal performance without pre-knowledge of channel statistics. After theoretical derivations and simulation analysis, 400Gbit/s and 1Tbit/s experiments will be conducted to verify our results. The accomplishment of this project is not only of great importance and significance for the research of coherent OFDM, but also a crucial improvement for the development of our next generation high-speed optical communication system.

高速相干光通讯系统是解决互联网及民用通信带宽需求骤增的关键技术。相干光正交频分复用(OFDM)技术以其低损耗，高安全性，高带宽利用率等优点吸引国内外大量研究。运用小体积，低成本的数字信号处理(DSP)芯片实现噪声补偿，具有重要的战略意义和研究价值。.本项目立足于对当前国际先进的相干光OFDM系统中噪声补偿算法的研究和发展，自主开发一种新型基于Viterbi算法的最大似然序列检测技术来补偿信道失真尤其是相位噪声。该方法利用整个数据序列进行联合分析，可以显著提高对噪声的免疫力，运用Viterbi算法使接收机的计算量大幅简化。该算法还可在无信道及系统参数信息的情况下自动优化，让误码率达到最低。在理论推倒及仿真分析后，将搭建400Gbit/s及1Tbit/s实验平台进行验证和检测。本项目的完成可填补国内相干光OFDM序列检测的空白，超越国际先进水平，大力推动未来高速光纤通讯的快速发展和广泛应用。

高速相干光通讯系统是解决互联网及民用通信带宽需求骤增的关键技术。相干光正交频分复用(OFDM)技术以其低损耗，高安全性，高带宽利用率等优点吸引国内外大量研究。运用小体积，低成本的数字信号处理(DSP)芯片实现噪声补偿，具有重要的战略意义和研究价值。.本项目立足于对当前国际先进的相干光OFDM系统中噪声补偿算法的研究和发展，提出了1）基于增强型自适应DA-ML的载波相位估计以及应用，实现稳定的载波相位估计以及激光器线宽、光信号信噪比估计；2）基于最小均方误差的载波相位估计，充分考虑估计窗内信号的载波相位浮动，克服估计窗长的变化对估计结果的影响，大幅提高对相位噪声及窗长选择的容忍度。.上述研究成果形成了学术论文39篇、申请专利7篇。