基于数字信号处理技术的光高速高阶QAM概率整形技术研究是解决高速光纤通信系统中器件和信道线带宽受限问题的核心理论与方法。本项目在深入研究高速光纤通信和信号成形理论等基础上，提出逼近香农极限的概率成形信号编码与调制理论及相关算法、基于概率整形的高阶调制光信号产生、传输和接收技术中的数字信号处理方法，提出基于发射机端的数字信号预处理算法与编码方法、基于接收机端的低复杂度数字信号后处理算法和概率整形的高谱效率相干光系统信号产生与处理方法、基于FEC的最佳概率分布优化算法，建立从16QAM到2048QAM光高阶调制码和速率单通道超过1Tb/s的概率整形信号产生、传输与零差或外差相干接收的实验验证平台；进行性能分析和方案优化。该项目的研究成果将为超高速率、超大容量和超长距离高频谱效率和高灵敏度的光传输系统的实现提供新途径，促进我国光纤通信技术的发展。

The research of optical high-speed high-order QAM probability shaping technology based on digital signal processing technology is the core theory and method to solve the problem of limited bandwidth of devices and channel lines in high-speed optical fiber communication system. Based on the deep research ofhigh-speed optical fiber communication and signal shaping theory, this project proposes the probability-shaping signal coding and modulation theory and related algorithms that approximate the Shannon limit. The Signal processing method of high-order modulated optical signal generation, transmission and reception based on Probabilistic Shaping is presented. Digital signal preprocessing algorithm and coding method in transmitter end, low complexity digital signal post-processing algorithm in receiver end, and high spectral efficiency coherent optical signal generation and processing method using Probabilistic Shaping are also presented. And optimal probability distribution optimization algorithm based on FEC is proposed.Experimental verification platform is established about optical high-order modulation code and the rate of single-channel more than 1Tb / s probabilistic shaping signal generation, transmission and homodyne / heterodyne coherent reception from 16QAM to 2048QAM. The performance is analyzed and program is optimized. The research results of this project will provide a new way for the realization of optical transmission systems with ultra-high speed, large capacity and long-range high spectral efficiency and high sensitivity, and promote the development of optical fiber communication technology in China.