基于stokes空间中信号高阶累积量的相干光通信调制识别研究

项目名称： 基于stokes空间中信号高阶累积量的相干光通信调制识别研究

项目编号： No.61505266

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 刘洁

作者单位： 中山大学

项目金额： 18万元

中文摘要： 具有高频谱利用率、高适配性的认知光网络被普遍认为是下一代光网络的重要选择之一，其自主认知的特点需要相干光接收机具有调制格式识别功能。不同于无线通信，相干光通信中的调制格式识别需要克服大相位噪声、偏振相关损伤以及光纤非线性损伤等的影响。针对以上问题，提出一种以信号stokes空间中信号的高阶累积量为特征值的调制格式识别算法。该算法对相位噪声、频率偏移、以及两偏振信号间的混合串扰不敏感。在此基础之上，主要研究高斯白噪声、偏振时变性、偏振模式色散以及光纤非线性损伤对特征值的影响。其中，针对偏振时变系统，提出奇异值分解与stokes空间自适应收敛级联的预处理算法；针对偏振模式色散和光纤非线性，分别引入减法聚类和似然比分类器算法，并进行简化。最后搭建偏振复用高速光通信实验系统，进行算法验证及优化。本项目将发展与现有数字信号处理模块兼容性好、较低复杂度的调制格式识别算法，为下一代光网络升级提供参考依据

中文关键词： 高速相干光通信；数字相干接收机；高阶调制码型

英文摘要： Cognitive optical networks (CON) combined with coherent detection and digital signal processing (DSP) is considered a very promising solution for next generation optical networks. The autonomous cognitive transmitters in CONs makes that the modulation formats be selected dynamically, which in turn makes it necessary for the receivers to classify the modulation format of incoming signals. Various challenges including phase noise, frequency offset, polarization dependent loss (PDL), polarization mode dispersion (PMD), fiber nonlinearity, etc., lay before the modulation format classification (MFC) schemes in coherent optical communication systems. To address this problem, a three-year project on MFC by extracting and identifying specific features from the high order cumulants of signals in stokes space, is proposed. The proposed MFC scheme has the advantage of insensitive to phase impairments, and polarization mixing, and low complexity. The impact of Gaussian white noise, PMD as well as the fiber nonlinearity on the MFC performance will be investigated. Meanwhile, a cascaded pre-processing algorithm using singular vector decomposition (SVD) and stokes space based adaptive convergence algorithms will be proposed and investigated in the time varying state of polarization (SOP) systems. Furthermore, the simplified subtractive clustering and likelihood ratio classifier will be introduced to decrease the impact of PMD and fiber nonlinearity, respectively. The abovementioned algorithm will then be experimentally investigated and evaluated in a polarization division multiplexed (PDM) coherent optical transmission system.

英文关键词： high-speed coherent optical communication;digital coherent receiver;high-order modulation format