高速光通信是目前光通信领域中最为热门的研究方向之一。在研究TCM、Turbo码、LDPC码的构造方法与编解码调制解调基本原理、高速光传输理论的基础上，提出适合高速光通信的Turbo码或LDPC码与TCM相结合的新型编码调制格式、编码调制与解调译码算法和实现方案；从高速光传输理论出发，提出200Gb/s 光OFDM信号产生方案；将新型编码调制技术与光OFDM技术相结合，提出基于新型编码调制格式的、可实现最高兼容200Gb/s的变速率光OFDM系统实现方案，建立实验演示系统，进行性能分析和方案优化。该项目的研究成果解决高速光OFDM系统中多速率混传问题，为高速、大容量、可变速率的光通信系统实现提供新途径。

High-speed optical communication is one of the most popular research directions in optical communications field. Many channel codes construction methods and encode-modulation/demodulation-decode principles such as Turbo code, LDPC（Low Density Parity Check） code and TCM（Trellis code Modulation） code have been researched. On this basis, a novel code modulation construction method, called LDPC-TCM or Turbo-TCM, will be constructed for high speed optical fiber communication. Its code modulation,decode demodulation algorithm and realization scheme will be proposed. On the basis of studying high-speed optical transmission theory，200Gb/s optical OFDM（Orthogonal Frequency Division Multiplexing） signal generate scheme will be put forward. And applied proposed novel code modulation method in optical OFDM system, a 200Gb/s variable-rate optical OFDM system based on the novel code modulation format will be presented,analized and experimentally verified. The research results of this project can solve the problem of multi-rate hybrid transmission in high-speed optical OFDM system and provide a new way in realizing high-speed, large capacity, multi-rate optical fiber communication.