摘 要

CDMA概念可以簡單地解釋為基于擴頻通信的調(diào)制和多址接入方案。其反向鏈路有接入信道和反向業(yè)務(wù)信道組成。接入信道用于短信令消息交換、能提供呼叫來源、尋呼響應(yīng)、指令和注冊。
本設(shè)計選取CDMA通信系統(tǒng)中的接入信道部分進行仿真與分析。首先，通過學(xué)習(xí)相應(yīng)的理論知識，熟悉接入信道實現(xiàn)的過程，對每一步的原理有了較深的理解，同時，也對MATALB軟件進行熟悉和了解，對MATLAB軟件中的SIMULINK部分及其內(nèi)部的CDMA模塊用法和參數(shù)設(shè)置進行熟悉，然后運用MATLAB軟件對接入信道部分進行設(shè)計，并逐步地對各個模塊進行分析、仿真與驗證。目的是通過畢業(yè)設(shè)計工作熟悉現(xiàn)代無線通信系統(tǒng)的基本構(gòu)成與基本工作原理，重點掌握卷積編碼、塊交織和碼擴展等相關(guān)編碼技術(shù)，并能將這些技術(shù)應(yīng)用實際系統(tǒng)設(shè)計，提高自己對CDMA通信系統(tǒng)知識的認識。

關(guān)鍵字：CRC;卷積編碼;塊重復(fù);交織;長碼;沃爾什;PN序列


















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 net ,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 the 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.
This design choose the part of connect channel to simulate and analyse. First,we can familiar with the process of connect channel ,understand the principleof every step of the procedure about thre channel,after studying the relating knowledge .At the same time ,we an also have some acquaintance with the software about MATLAB and the part of SIMULINK and how to set the parameter of every klock in the soft.Then we can use the MATLAB software to design the part of the connect channel, to analyse , to simulate and to validate the design of every block gradually. This purpose is to be familiar with the basic structure and basic principle of the morden wireless communication system, to mastery the technology about the Convolutional Encoder,Interleaver ,Coder spread and so forth, then use those technology to design system in practice,so that to improve our knowledge about the CDMA communication system.

Key words:CRC;Convolutional Enconder;Block Repeat;Interleaver;Long code;Walsh;
PN sequence









目 錄

中文摘要 關(guān)鍵字 …………………………………………………….……1
英文摘要 關(guān)鍵字 ………………………………………………….………2
目 錄 ……………………………………………………………….……...3
前 言 ………………………………………………………………..……..4
1 設(shè)計總體框架 ……………………………………………………..……5
2 設(shè)計各個部分原理知識介紹 ………………………………………..…6
2.1 卷積編碼……………………..………………………………………..…..7
2.2 交織技術(shù)介紹………………………..………….…………………………9
2.3 沃爾什函數(shù)說明………………………………..….………………………11
2.3.1 沃爾什函數(shù)特性說明………………………….…………………...……11
2.3.2 沃爾什函數(shù)的產(chǎn)生方法介紹……………………………………………..13
2.4 長碼的實現(xiàn)……………………………………………………………….15
2.6 PSK和OQPSK調(diào)制…………………………………………………………18
2.7 短碼的實現(xiàn)……………………………………………………….……….20
3 MTALAB軟件中的SIMULINK的簡介…………………………….………20
4 設(shè)計仿真、分析與驗證……………..………………………….……….22
4.1 設(shè)計總體模塊構(gòu)造…………………………..…………………….……….22
4.2 對各個模塊進行分析與驗證 ………………………………….……………23
4.2.1 源中部分（subsystem1）設(shè)置、說明與分析……………………………...24
4.2.2 對卷積編碼器和重復(fù)模塊的設(shè)置、說明與分析 …………………………27
4.2.3 對子系統(tǒng)Subsystem2（塊交織器）模塊的設(shè)置、說明與分析 ……………30
4.2.4 沃爾什調(diào)制器輸出與長碼輸出及其異或驗證…..………………….………40
4.2.5 I路和Q路的輸出驗證與分析……………………………………………46
5.經(jīng)驗總結(jié)…………………………………………………………………..49
謝 辭………………………………………………………………………..50
參考文獻……………………………………………………………………..51



參考文獻:
[1] Vijay K.Garg(美). 第三代移動通信系統(tǒng)原理與工程設(shè)計（于鵬等譯）[M]. 北京：電子工業(yè)出版社，2001：1～102.
[2] Man Young Rhee(韓). CDMA蜂窩移動通信系統(tǒng)與網(wǎng)絡(luò)安全 （袁超偉等譯） [M]. 北京：電子工業(yè)出版社，2002：1～122.
[3] Theodore S.Rappaport(美). 無線通信原理與應(yīng)用（蔡濤等譯） [M].北京：電子工業(yè)出版社，1999：1～388.
[4] 王興亮. 數(shù)字通信原理與技術(shù)[M]. 西安：西安電子科技大學(xué)出版社，2001：13～148
[5] Lee.J.S、Miller.L.E(美). CDMA系統(tǒng)工程手冊（許希彬）[M]. 北京：..