1、 毕业论文毕业论文 CDMA 数字移动通信数字移动通信系统系统信道编码信道编码 的实现的实现 专业名称:专业名称: 电子信息工程电子信息工程 班班 级:级: 20200 05 5级级1 1 班班 I 摘要摘要 CDMA技术是当前无线电通信, 尤其是移动通信的主要技术, 不论是在中国 已经建立的IS-95规范的中国联通CDMA网、 各大移动通信运营商正准备实验及 建立第三代(3G)系统还是大设备研发商已经在开发的三代以后(也称为4G) 带宽更宽的移动通信系统,CDMA 都是主要的选择。CDMA概念可以简单地解 释为基于扩频通信的调制和多址接入方案。其反向链路有接入信道和反向业务信 道组成。接入信
2、道用于短信令消息交换、能提供呼叫来源、寻呼响应、指令和注 册。 本设计对CDMA通信系统信道编码进行实现。首先,通过学习相应的理论 知识,熟悉接入信道实现的过程,对每一步的原理有了较深的理解;然后,用 ALTERA 的 MAX+ PLUS II系统来开发,它具有强大的功能,支持原理图、硬 件描述语言(VHDL,AHDL, verilogHDL)等多种输入方式。用FPGA来实现数字 移动通信信道编码, 大大简化了系统结构。 而且VHDL描述语言的使用缩短了开 发时间,增强了系统的可读性,便于后续产品的升级。最后,逐步地对各个模块 进行分析、仿真与验证。目的是通过毕业设计工作熟悉现代无线通信系统的
3、基本 构成与基本工作原理,重点掌握CRC 校验、卷积编码、块交织等相关编码技术, 并能将这些技术应用实际系统设计。 关键词 扩频通信; 码分多址; 信道编码; FPGA II Abstract CDMA is the major technology used in the wireless communication, especially in the mobile communication. Following the IS-95 standard set up in China, CDMA is the mostly choice whether in China Uninet ne
4、t, in the third system (3G) that all kinds of mobile businessmen are to build or in the wider system than the third one (named 4G) that the large equipments researching businessmen have been researching. The concept of CDMA may be interpreted as the simulation that base on frequency spreading and th
5、e multiply address access project. Its reverse channel is composed of access channel and traffic channel. The access channel is used for brief information exchanging 、providing the source about the calling、the call responding 、the instruction and the enrollment. The channel code of CDMA communicatio
6、n system is realized in the design. First, the process of connect channel will be familiar; the principle of every step of the procedure about the channel will be understood, after the study of the relating knowledge. Then, with ALTERAs MAX+PLUS II development system, which has powerful functions to support the schematic diagram, hardware description language (VHDL, AHDL, verilogHDL) and other input methods. Using FPGA to realize digital mobile communication channel encoding, greatly si