基于WCDMA室内分布系统的设计研究.docVIP

摘 要 本文介绍了WCDNA室内分布系统在蜂窝移动通信工程中的设计与应用，从室外到室内描述网络的现状，并且介绍了无线信号在传输过程中的衰落现象。通过对建筑物内从低层到高层电磁环境的描述，分析了室内的孤岛、乒乓和盲区等现象。通过对楼内场强进行现场DT测试，归纳出了信号在室内覆盖的薄弱环节，并由此对边缘场强进行了分析，确定了边缘天线的安装位置；在选择覆盖方案的过程中，介绍了各种信号源的使用环境，针对各个场所内的电磁环境、场所的结构、楼层高度等各自不同的特点，业主对覆盖提出的不同要求，确定信号源的类型；对天馈分布系统、光纤分布系统等几种分布方式进行了比较，确定了该覆盖场所所适用的方式通过一系列的方案组合，对几个不同的方案，根据楼域的结构以及业主的要求进行改进，归纳出了最终所采用的方案，由此确定了天线、元器件、干线放大器等的布放位置。在室内覆盖完成以后，势必会改变大网原有的覆盖情况，将对大网产生一定的面影响，本文对信号的泄漏问题进行了分析，通过对边缘场强的计算和楼内的结构，提出了避免泄露的方法：分析了对所选用的宏基站呼损率所可能产生的影响并提出了解决的方法；从质差掉话、弱信号掉话、切换掉话三个方面提出了室内覆盖对基站掉话率产生的影响，并归纳出了产生以上三种掉话的原因以及在工程设计中应该注意的问题。提出在室内和室外同一导频信号之间会产生切换，原则上规定，进入室内就要用室内的信号，本文针对这个问题，归纳出了切换的控制和实现平滑过渡的方法。为今后的工作，打下了良好的基：室内分布系统······················································································································1 2 室内覆盖背景和意义·······················································································2 2.1移动通信现状和发展·············································································.2室内移动通信网络现状································································································2.3室内分布系统常见问题································································································.4建设室内覆盖系统的意义和重要性··············································································4 2.5 WCDMA室内覆盖规划建设原则·············································································· 3 室内分布天线系统···········································································································.1室内分布天线系统概述·········································································.2室内覆盖系统原理·················································································.2.1有源天线分布系统················································································.2.2光纤天线分布系统················································································.2.3无源天线分布系统················································································.2.4泄漏电缆分布系统···············································