CDMA無線網絡優化方法探討及案例分析

電子通信論文編號:TX230  有開題報告，任務書， 論文字數:19003,頁數:37

目錄
中文摘要 I
ABSTRACT II
1　引言 1
1.1　課題背景 1
1.1.1　移動通信行業發展 1
1.1.2　CDMA技術的發展現狀 1
1.2　本課題研究的目的和意義 2
1.3　本課題研究的主要內容 3
2　基本原理 4
2.1　CDMA基本概念 4
2.2　DS-CDMA的關鍵技術 4
2.2.1　功率控制技術 4
2.2.2　PN碼技術 5
2.2.3　RAKE接收技術 5
2.2.4　軟切換(Soft Handoff)技術 5
2.3　CDMA網基本結構系統 7
3　CDMA無線網絡優化流程和方法 8
3.1　CDMA無線網絡優化概述 8
3.2　CDMA無線網絡優化的發展 8
3.3　CDMA無線網絡優化的分類 9
3.3.1　工程優化 9
3.3.2　運維優化 10
3.4　CDMA無線網絡優化的通常流程 10
3.5　CDMA無線網絡優化的方法 12
3.6　CDMA無線網絡優化的主要內容 13
3.6.1　優化準備工作 13
3.6.2　現場測試 14
3.6.3　CLUSTER級的調整和優化 14
3.6.4　系統級優化（有負載） 15
4　CDMA網絡優化典型案例分析 16
4.1　CDMA無線掉話常見原因分析及優化 16
4.1.1　處干覆蓋范圍以外的掉話 16
4.1.2　導頻污染引起的掉話 18
4.1.3　前反向鏈路不平衡引起的掉話 19
4.1.4　干擾引起的掉話 20
4.2　CDMA網絡中切換問題 21
4.2.1　硬切換 21
4.2.2　軟切換及更軟切換 22
4.2.3　典型案例分析 25
4.3　總結 28
5　結束語 29
致謝 30
參考文獻 31

中文摘要
 CDMA是為滿足現代移動通信網在大容量、高質量、綜合業務、軟切換、國際漫游等方面的要求而設計的一種先進移動通信技術，它具有抗干擾性好，抗多徑衰落，保密安全性高等諸多優點。CDMA網絡是中國電信的主推品牌，CDMA2000 (3G)業務的發展直接影響到中國電信的成敗，而CDMA業務的發展必須依賴完善的網絡才能順利進行。因此，CDMA系統在運營過程中需要不斷地進行網絡優化，一是為了能夠給系統當前的用戶提供更加優質的服務，二是為了提高系統容量，以接納越來越多的系統未來用戶。
 本文的研究目標是對投入運行的網絡進行參數采集、數據分析，找出影響網絡運行質量的原因，通過技術手段或參數調整使網絡達到最佳運行狀態的方法，使網絡資源獲得最佳效益，同時了解網絡的增長趨勢，為擴容提供依據。具體的網絡優化主要包括以下幾方面內容: 網絡覆蓋問題；掉話問題；二次呼叫問題；越區切換問題；與其他網絡手機用戶的互連互通等。
 本課題主要研究CDMA無線通信網絡中掉話和切換問題的分析和優化。通過對覆蓋區基本情況、網絡覆蓋、質量、話務的分析，應用現有理論和技術，在前期工程的基礎上為完善CDMA網絡的覆蓋并優化網絡，提出切實可行的設計方案。使得網絡容量、質量、經濟效益、競爭力達到預期設定的目標值，最終滿足客戶市場的需求。
關鍵詞：無線網絡優化、CDMA、掉話問題、軟切換技術等

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