毕业设计（论文）--基于Multisim的CMI码编译码电路设计仿真及光纤传输实现.docVIP

基于Multisim的CMI码编译码电路设计仿真及其光纤传输实现 摘要： CMI码是一种应用于PCM四次群和光纤传输系统中的常用线路码型，它既为我国数字通信标准制式所规定的两种接口码型之一，又是数字光纤通信系统中所采用的线路码型，它既属于伪双极性码又属于mBnB码（1B2B码）。它也具有码变换设备简单、便于时钟提取等优点。 Multisim是全功能电路仿真系统，可以实现计算机仿真与虚拟实验，并且设计与实验可以同步进行，修改调试方便；设计和实验用的元器件及测试仪表齐全，可以完成各种类型的电路设计与实验；可方便地对电路参数进行测试和分析；可直接打印传输出实验数据、测试参数、曲线和电路原理图；实验中不消耗实际的实际的元器件，实验成本低、实验速度快、效率高。利用Mulitisim仿真软件对CMI码编译码电路进行框架设计、电路图编辑绘制、电路工作状况测试、电路特性分析，以展现在通信系统中线路码的传输过程，使自己对线路码编码、传输、译码有较全面直观的认识，从而加深对整个传输系统的理解。 关键字：CMI码、光纤、Multisim仿真软件、编译码电路 Summary 　　　Cmi code is a pcm Four groups and optical fiber used in the transport system of common line ode，It to the digital communication　formats standard set by two interface type of code, and a digital Optical Fiber Communication system used in the yard,It is two yards in the polarity of mbnb yards and yards （ 1b2b ）. it also has facilities for a change simply, the withdrawal of the advantages. 　　　Multisim circuit is the full implementation of the computer simulation system, imitation and experiment and to design included with the experimental can synchronize to update easy to debug；Design and experiment with Componentsand test meters, we can finish the various types of the circuit design with the experimental ； can be parameters to circuit test and analysis ； can print the transmission of data and testing in the experiment parameter, with the principle of a circuit diagram ；Componentsandexperiment without actual actual Componentsand, the costs were low, the speed and efficiency.mulitisim simulation software code compiler with a circuit frames design, the circuit diagram or circuit diagrams work condition, quality tests made by the lines of communication systems in transit, in line to a code, transport and decoding to be comprehensive and intuitive knowledge and to further enhance the entire transport system to understand. Keyword ： cmi, optic fibres, multisim simulation software, compile a circuit  前言： 在数字光纤通信系统中光纤所传输的信号码不能是简单的“0”“1”二电平信号 因为信号中的直流信息会造成接收端的判决问题。因此,在信号转换为光信号之前 应该对过来的信