摘要
在无线监测工作中需要对无线信号进行测试并进行测量，在一些情况下需要对大量的数据进行处理，然后作出相关的结论。显然，快速、简洁的处理数据是必要的且需要去不断改进和提高的。现有的测试仪器尽管在体积越来越紧凑，操作方式越来越简洁，但是还是存在一些缺点，仪器的使用对象针对性仍然不够强，一些操作还是显得烦琐，比如测试中当一些天线、传输线等需要及时调整时，它们的修正因子同时也要作一些变化，在仪器中并没有存储这些数据，需要实时输入。有时由于处理数据的实时性不强，会把本身就耗时的测试过程拖得更加的漫长。而且，一般情况下仪器也不能实现无人职守。以上这些缺点对经常需要在野外进行的测试工作而言是尤为突出的。测试时对于历史数据的保存在一些场合也是有必要的，怎样保存好数据以供日后分析也是应当纳入考虑的问题之一。
本文通过用Agilent的E7405A分析仪和计算机的联机使用构成一台“虚拟仪器”来解决以上问题 ，该“虚拟仪器”有针对性的简化了E7405A的操作，按照实际工作的需要进行了功能的划分，同时，对无线监测中的一个重点和难点的问题“寻呼信号的三阶互调的干扰的分析”提出并实现了相关的应对方法。本文首先介绍了本系统的硬件结构以及与之相关虚拟仪器的基本概念和相关技术，对相关技术之间的层次关系进行了分析。其次，讨论了无线寻呼系统中的互调干扰问题，分析了互调干扰频率相互之间的关系，以及互调干扰的特点，互调干扰查找中的计算量的大小问题。第三，对寻呼信号的频谱作了原理上的介绍，并对寻呼信号之间的互调干扰的频谱形式从原理上作了一些探讨，从而对实际工作中的干扰查找提供了一点帮助。最后，介绍了建立在该虚拟仪器之上的无线电电磁环境的测试分析系统的设计，主要是介绍了系统的软件结构以及相关的应用举例。
Measure and test of radio signals are the important task for radio managing station. The data from measure or test will be treated, and the conclusion will be drawn. Sometimes there are a mass of data need to be treated. Obviously, the way of treating the data quickly and clearly is very necessary. Today, the instrument is more and more compact and the methods to operation are more smarter. But there are some disadvantage. Sometimes we need more special way to some purpose. Some operation are complex too. The instrument's setting must be changed when there are some component such as a antenna or a transmission line replaced. The correction factors of a antenna or a transmission are mass but the instrument can not save it., so it is very labouredly that the factors are keyed in. A lot of task of the radio managing station are disposed on the field, it means that saving time is very important. The test data in the past maybe useful, and how to save data for analysis in the future is a matter we will deal with.
In this dissertation the author proposed a "virtual instrument" which is based on a computer and a E7405A analyzer. The "virtual instrument" predigest the operation of E7405A to adapt the instrument to the demands of the radio managing station. The functions of the E7405 are grouped again according to the need of task. A method of detecting the intermodulation interference which are produced by paging transmitters is proposed in this dissertation too. In this dissertation, the hardware structure is presented at first, and the concept of virtual instrument, the layer's architecture of virtual instrument standard are described too. Secondly, some questions about intermodulation interference are presented and discussed. The spectrum model of intermodulation interference which are generated by paging transmitters are shown and derived. Finally, the software of the system, which is called "Measure and analyse system for radio electromagnetic environment managing", is described in this dissertation and the result of one test is shown.
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