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毕业设计(2014届)题目移动通信系统中的切换技术研究学院物理电气信息学院专业电子信息工程年级2010级学生学号12010245352学生姓名张洋指导教师朱瑜红2014年4月29日I摘要自从移动通信领域中引入的蜂窝概念，切换技术就开始出现，并成为了移动通信系统中的重要技术之一。切换技术是蜂窝系统所独有的功能，也是移动通信系统的一个关键特征，它直接影响整个系统的性能。当移动台的一个基站的覆盖范围移动到另一个基站的覆盖范围，通过切换移动台保持与基站的通信。切换从本质上说是为了实现移动环境中数据业务的小区间连续覆盖而存在的，从现象上来看是把接入点从一个区换到另一个区。本文研究的重点是移动通信系统中的切换技术，主要分析了CDMA、GSM、WCDMA系统中的切换过程，切换基本可以分为硬切换、软切换和更软切换。由于第二代移动通信系统的巨大成功，用户的高速增长与有限的系统容量和有限的业务之间的矛盾，第三代移动通信的标准化工作已经进入实质阶段。3G通信技术已经成熟，新的4G技术也在不断的发展，要做到通信技术的完善和更前的发展，切换技术作为移动通信中的关键技术，起着重要的作用。因此，我们研究切换技术是为了更好的发展未来通信技术，提高网络的服务能力和运行质量。关键词:切换,硬切换,软切换,切换算法IIAbstractSincetheintroductionofmobilecommunicationinthefieldofcellularconcepts,switchtechnologybegantoappearasmobilecommunicationssysteminoneoftheimportanttechnology.Switchingtechnologyisacellularsystemfunctionuniquetothemobilecommunicationisalsoakeyfeatureofthesystem,itdirectlyaffectstheperformanceoftheentiresystem.Whenamobilebasecoveragemovingtoanotherstationcoverage,throughtheswitchandmobilecommunicationstations.Switchessentiallyforthemobileenvironmentdatabetweenthebusinesscommunityandthecontinuouscoveragefromthephenomenonexists,itistheaccesspointfromoneregiontoanotherregion.Thispaperfocusesonmobilecommunicationsystemswitchingtechnology,focusedontheCDMA,GSM,WCDMAsystemswitchingalgorithm,switchBasiccanbedividedintohardswitching,soft-switch,moresoftswitch.Becausethesecondgenerationofmobilecommunicationsystemswithgreatsuccessin,theuser'shigh-growthandlimitedsystemcapacityandlimitedbusinessconflictsbetweenbecomingobvious,thirdgenerationmobilecommunicationsstandardworkbegantograduallyintothesubstantivephase.3Gcommunicationtechnologyhasslowlymatured,thenew4gtechnologyevolutioncontinues,inordertoachievetheperfectionofcommunicationtechnologyandthedevelopmentofmore,beforeswitchingtechnologyasthekeyinmobilecommunicationtechnology,playsakeyrole.Therefore,westudyswitchingIIItechnologyinordertobetterdevelopfuturecommunicationtechnology,increasenetworkcapacityandquality.KEYWORDS：Handover,Hard-handover,Soft-handover,Handover-algorithmsIV目录第一章绪论..............................................................................................................................11.1移动通信系统..................................................................................................................11.1.1移动通信特点...........................................................................................................11.1.2移动通信工作方式...................................................................................................11.2移动通信的发展..............................................................................................................21.2.1全球移动通信发展历程...........................................................................................21.2.2我国移动通信的发展历程.......................................................................................41.3研究的内容及意义..........................................................................................................4第二章切换技术......................................................................................................................52.1切换技术的发展...............................................................................................................52.2切换的定义及分类..........................................................................................................52.3切换的原因.......................................................................................................................62.4切换的控制方式...............................................................................................................7第三章移动通信系统中的切换............................................................................................83.1CDMA系统中的切换......................................................................................................83.1.1CDMA系统概述.......................................................................................................83.1.2CDMA系统中的软切换...........................................................................................93.1.3CDMA系统中的硬切换.........................................................................................123.2GSM系统中的切换.......................................................................................................143.2.1GSM系统概述........................................................................................................143.2.2GSM数字移动通信的主要技术............................................................................153.2.3GSM切换................................................................................................................163.3WCDMA系统中的切换................................................................................................183.3.1WCDMA系统概述.................................................................................................183.3.2WCDMA中的切换.................................................................................................183.3.3WCDMA中的软切换....................................................................................