中文摘要：

基于高速光传输系统中信道内四波混频（IFWM）作用机理，提出了一种新的调制格式，通过在1码间以双0双π的相位间隔来抑制IFWM效应和寄生脉冲的产生，通过IFWM扰动项间的相互抵消减少光纤非线性带来的传输代价。数值仿真发现，在传2个典型码列“11011”和“11100”时，该调制格式比传号交替反转（AMI）码和普通归零码（RZ）等格式抑制的效果更好、抑制的脉冲模式更广泛。在40Gbps光传输系统中，如果以1dB眼图代价为评判标准，AMI格式比RZ优2dB，而本文格式比AMI优越1dB，并且是与AMI格式同样容易实现的码型。

英文摘要：

The paper analyses the effects of intra-charmel four-wave mixing（IFWM） on the high-speed optical fiber comrnuni cations system. A new code format is presented,which separates code 1 with double 0 and double π phase,and it can decrease the transmission penalty caused by fiber nonlinearity through the counteract of perturbation terms of IFWM. From the simulation of the tranmission of two classic code data ＂11011＂ and ＂11100＂ ,we find that our proposed code format has better suppression effect than alternative modulation inversion（AMI） or normal RZ format and supports wider pulse mode. In 40 Gbps system,AMI format is 2 dB less than RZ format and our proposed format is I dB less than AMI format when 1 dB eye open penalty is taken as a metewand. Moreover,the proposed format can be realized as easily as AMI format.