武汉理工大学《FPGA原理与应用》课程设计说明书
课程设计任务书
学生姓名： 专业班级： 通信1104 指导教师： 陈适 工作单位： 信息工程学院 题 目: 数字基带信号传输码型发生器设计 初始条件：
FPGA芯片（型号不限），仿真工具不限。
要求完成的主要任务: （包括课程设计工作量及技术要求，以及说明书撰写等具体要求）
要求每位选课同学提交一篇关于FPGA的应用设计报告，选择的FPGA芯片不限，选用的仿真工具不限。格式要求按照课程设计报告的标准格式完成，包括： 常见的几种基带码 ： 1.单极性非归零码 2.双极性非归零码 3.单极性归零码 4.双极性归零码 5.差分码 6.交替极性码 7.分相码
8.编码信号反转码
指导教师签名： 年 月 日
系主任（或责任教师）签名： 年 月 日
武汉理工大学《FPGA原理与应用》课程设计说明书
目 录
摘 要 ················································································································································ I Abstract ·········································································································································· II 1前言 ·············································································································································· 1 2 数字基带信号 ····························································································································· 2
2.1 数字基带信号的码型设计原则 ·············································································· 2 2.2 非归零码(NRZ 码) ································································································· 3
2.2.1 单极性 ··········································································································· 3 2.2.2 双极性 ··········································································································· 3 2.3 归零码(RZ 码) ········································································································ 3
2.3.1 单极性 ··········································································································· 3 2.3.2 双极性 ··········································································································· 4 2.4 差分码 ······················································································································ 4 2.5 交替极性码(AMI 码) ····························································································· 5 2.6 分相码(曼彻斯特码) ······························································································· 5 2.7 传号反转码(CMI 码) ······························································································ 6
3 EDA概述 ····································································································································· 7
3.1 VHDL ························································································································ 7 3.2 FPGA ························································································································· 8
4 基带码发生器的设计原理 ········································································································· 9
4.1 基带码发生器的原理框图 ······················································································ 9 4.2 码型转换原理 ········································································································ 10
5软件设计与仿真 ························································································································ 11
5.1 VHDL程序设计 ····································································································· 11 5.2 软件仿真及结果分析 ···························································································· 13
5.2.1 器件仿真结果 ····························································································· 13 5.2.2 波形仿真结果 ····························································································· 13
6 总结与体会 ······························································································································· 17 7 参考文献 ··································································································································· 18
武汉理工大学《FPGA原理与应用》课程设计说明书
摘 要
设计一个基于FPGA 的数字基带信号发生器，首先简要介绍了单极性非归零码、双极 性非归零码、单极性归零码、双极性归零码、差分码、交替极性码、分相码、传号反转码 等基带码的基本特点，然后根据码型转换原理设计发生器模块。由于EDA 技术可以简化 电路，集成多块芯片，减小电路体积，所以程序采用VHDL 进行描述，并用quartusII 软件仿真实现所有功能，最后将功能集成到FPGA 上，并设计电路，产生的基带码稳定、可靠，可满足不同数字基带系统传输需要。 关键词：数字基带码，EDA，VHDL，FPGA
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武汉理工大学《FPGA原理与应用》课程设计说明书
Abstract
FPGA-based design a letter-number generator with, first of all we briefly introduce unipolar NRZ code, bipolar NRZ, Unipolar zero yards code, bipolar zero yards code, differential code ,alternating polarity code, phase code, code-reversal, and third-order high-density bipolar codes etc. Then we design generator module under the code-conversion design principles. As EDA technology can make circuit simple , integrate multiple chips, reduce the size of circuits, so we take advantage of VHDL to describe it and use quartusII software to simulate .Finally we integrate all the fetures into the FPGA, and design circuit to generate stable and reliable base-band code to meet the different base-band digital transmission system needs. Keywords: digital base-band code， EDA ，VHDL ，FPGA
II
武汉理工大学《FPGA原理与应用》课程设计说明书
1前言
近年来，随着大规模集成电路的出现，数字系统的设备复杂程度和技术难度降低，数 字通信系统的主要缺点逐渐得到解决，因此数字传输方式日益受到欢迎。
数字传输系统中，传输对象通常是二元数字信息，而设计数字传输系统的基本考虑是选择一组有限的离散的波形来表示数字信息。这些取值离散的波形可以是未经调制的电信号，也可以是调制后的信号。未经调制的数字信号所占据的频谱是从零域或很低频率开始，称为数字基带信号。不经载波调制而直接传输数字基带信号的系统，称为数字基带传输系统。数字基带传输系统方框图如图1-1所示。
基带脉冲输入 接受滤波 抽样判决 输出 信道信号 形成信道 器 器 噪声
同步提取 图1-1 数字基带传输系统方框图
目前，虽然数字基带传输的应用不是很广泛，但对于基带传输系统的研究仍然十分有 意义，主要是因为：
1、在利用对称电缆构成的近程数据通信系统中广泛采用了这种传输方式； 2、随着数字通信技术的发展，基带传输方式也有迅速发展的趋势； 3、基带传输中包含带通传输的许多基本问题；
4、任何一个采用线性调制的带通传输系统，可以等效为一个基带传输系统。
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