【作者】 龚岷安；

【导师】 张晓萍；

【作者基本信息】 兰州大学 ， 通信与信息系统， 2013， 硕士

【摘要】 随着人们对互联网的使用逐渐增加,高流量的应用程序的出现对网络传输速率提出了更高的新的要求,使光纤通信系统向着100Gbit/s甚至更高的传输速率演进。光正交频分复用技术以其频谱利用率高、抗色散的优势成为了高速光纤通信系统的方案之一,引起了广泛的研究热情。本文对影响光正交频分复用系统信号传输质量的光纤非线性效应进行了研究,尤其是对影响光正交频分复用系统信号传输质量最为严重的四波混频效应进行了具体的研究。本文通过利用基于Volterra级数的非线性薛定谔方程的闭式半解析解对光正交频分复用系统进行求解,得到了包含线性项和非线性项的光正交频分复用系统的传播方程的近似解,利用四波混频效应的定义,从非线性项中分离出了对光正交频分复用系统影响最大的四波混频效应的表达式。该表达式可体现色散和非线性效应的相互作用,并且包含了相位失配,较之以往的结论更为贴近实际情况,分析结果更为精确。对所得表达式进行数值仿真,验证了本文所给出的光正交频分复用中的四波混频的表达式更为贴近实际系统。数值仿真的结果还表明,光正交频分复用系统中某一子载波所受的四波混频的影响主要来源于与其相临近的子载波,而与它频率间隔较大的子载波的影响可以忽略,因此可以对基于Volterra级数传递函数的光正交频分复用系统四波混频效应的表达式进行简化,降低其计算复杂度,为通过Volterra级数传递函数设计光正交频分复用系统的优化方案提供了理论依据。更多还原

【Abstract】 With the use of the Internet is gradually increased, the application of high flow forward higher and new requirements for the network transmission rate, the optical fiber communication system to100Gbit/s or even higher transmission rate evolution. One of the high-speed optical fiber communication system as Optical Orthogonal Frequency Division Multiplexing(OOFDM) technology due to its high rate of resistance to dispersion spectrum, the advantages, attracted extensive research enthusiasm. In this paper, fiber nonlinear effect on Optical Orthogonal Frequency Division Multiplexing system signal transmission quality were studied, especially for the most important effection:Four Wave Mixing (FWM) effect.In this paper, Volterra series Transfer Function model of nonlinear Schrodinger equation was used to study Optical Orthogonal Frequency Division Multiplexing system. The approximate solution is obtained propagation equation contains linear term and nonlinear term, and then based on the defination of the four wave mixing effect, isolated the expression of four wave mixing effect on Optical Orthogonal Frequency Division Multiplexing system. The expression to represent the Four Wave Mixing in Optical Orthogonal Frequency Division Multiplexing system was obtained, with considering dispersion and phase mismatch. The results of computer simulation show that the power of Four Wave Mixing products are different from each other, and Four Wave Mixing effect in a certain subcarrier only derives its adjoining subcarriers, the effect of other subcarriers could be ignored. So in practical application, the expression of Four Wave Mixing in Optical Orthogonal Frequency Division Multiplexing system could be simplified, to reduce the computational complexity, and provides a theoretical basis for the optimization of Volterra series transfer function design of optical orthogonal frequency division multiplexing system.更多还原