cdma无线网络优化方法探讨及案例分析.doc

CDMA无线网络优化方法探讨及案例分析


目录
中文摘要 I
ABSTRACT II
1　引言 1
1.1　课题背景 1
1.1.1　移动通信行业发展 1
1.1.2　CDMA技术的发展现状 1
1.2　本课题研究的目的和意义 2
1.3　本课题研究的主要内容 3
2　基本原理 4
2.1　CDMA基本概念 4
2.2　DS-CDMA的关键技术 4
2.2.1　功率控制技术 4
2.2.2　PN码技术 5
2.2.3　RAKE接收技术 5
2.2.4　软切换(Soft Handoff)技术 5
2.3　CDMA网基本结构系统 7
3　CDMA无线网络优化流程和方法 8
3.1　CDMA无线网络优化概述 8
3.2　CDMA无线网络优化的发展 8
3.3　CDMA无线网络优化的分类 9
3.3.1　工程优化 9
3.3.2　运维优化 10
3.4　CDMA无线网络优化的通常流程 10
3.5　CDMA无线网络优化的方法 12
3.6　CDMA无线网络优化的主要内容 13
3.6.1　优化准备工作 13
3.6.2　现场测试 14
3.6.3　CLUSTER级的调整和优化 14
3.6.4　系统级优化（有负载） 15
4　CDMA网络优化典型案例分析 16
4.1　CDMA无线掉话常见原因分析及优化 16
4.1.1　处干覆盖范围以外的掉话 16
4.1.2　导频污染引起的掉话 18
4.1.3　前反向链路不平衡引起的掉话 19
4.1.4　干扰引起的掉话 20
4.2　CDMA网络中切换问题 21
4.2.1　硬切换 21
4.2.2　软切换及更软切换 22
4.2.3　典型案例分析 25
4.3　总结 28
5　结束语 29
致谢 30
参考文献 31

 
中文摘要
CDMA是为满足现代移动通信网在大容量、高质量、综合业务、软切换、国际漫游等方面的要求而设计的一种先进移动通信技术，它具有抗干扰性好，抗多径衰落，保密安全性高等诸多优点。CDMA网络是中国电信的主推品牌，CDMA2000 (3G)业务的发展直接影响到中国电信的成败，而CDMA业务的发展必须依赖完善的网络才能顺利进行。因此，CDMA系统在运营过程中需要不断地进行网络优化，一是为了能够给系统当前的用户提供更加优质的服务，二是为了提高系统容量，以接纳越来越多的系统未来用户。
本文的研究目标是对投入运行的网络进行参数采集、数据分析，找出影响网络运行质量的原因，通过技术手段或参数调整使网络达到最佳运行状态的方法，使网络资源获得最佳效益，同时了解网络的增长趋势，为扩容提供依据。具体的网络优化主要包括以下几方面内容: 网络覆盖问题；掉话问题；二次呼叫问题；越区切换问题；与其他网络手机用户的互连互通等。
本课题主要研究CDMA无线通信网络中掉话和切换问题的分析和优化。通过对覆盖区基本情况、网络覆盖、质量、话务的分析，应用现有理论和技术，在前期工程的基础上为完善CDMA网络的覆盖并优化网络，提出切实可行的设计方案。使得网络容量、质量、经济效益、竞争力达到预期设定的目标值，最终满足客户市场的需求。
关键词：无线网络优化、CDMA、掉话问题、软切换技术等

ABSTRACT
CDMA is a kind of advanced mobile telecommunication technology, which fulfill great capacity and quality、synthetical operation、soft switch and international ramble. It possesses lots of merits such as repellence of interference and attenuation of multiple paths. The security is also great trait of CDMA. CDMA is the main operation that China Unicorn extend .The progress of CDMA right result in the success of China Unicom，and the development of operation must depend on perfect network. Therefore, in the process of management, it is completely necessary to optimize CDMA wireless network constantly On the one hand, the purpose of optimizing CDMA wireless network is to provide more consummate service, and on the other hand, it is to extend system capacity in order to take up more and more consumers.
The purpose of this task is to investigate the best methods that can optimize CDMA wireless network by collecting data of network which is in operation and analyzing the data in order to find the cause which influences the quality of the network. The advantage of CDMA is application of power control and soft switch, so they are usually the emphases during base station optimizing. On the other hand, data optimizing is also important and difficult. Concretely, methods of optimizing are as following: l、the issue of network coverage 2、dropped calls problem 3、the second call issues 4、handoff issues 5、with other network users, such as the interconnection.
The main research topics of CDMA wireless communications network are dropped calls and switching analysis and optimization. Covered by the basic situation of the district, network coverage quality and traffic analysis. Applying of existing theory and technology, the basis of pre-engineering to improve the coverage of CDMA networks and optimized networks is practical designed. Makes network capacity, quality, cost-effective, competitive edge to achieve the desired target set, and ultimately meet customer needs of the market.
Keywords: wireless network optimization, CDMA, the issue of dropped calls, soft switching technology