在用广播电视台发射设备开场测试方法研究

发布时间：2018-03-02 18:03

本文选题：设备检测　切入点：开场测试　出处：《内蒙古大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前在用广播电视设备测试都采用传导测试方法,存在影响用户设备正常工作和效率低下等问题,若能找到有效的开场测试方法,则可以解决上述问题。本文首先介绍了三种主流的无线电波传播特性预测方法,并说明了确定性模型的优势所在,其次介绍了三种常用确定性模型并指出射线跟踪法在复杂城市环境中的应用非常广泛。接着重点阐述了射线跟踪技术的基本原理、分类、计算方法、几种常用的加速算法及本文采用八叉树分区算法的理由。本文要解决的是对广播电视发射设备进行开场测试的问题,考虑到测试点的选择一般都在发射台站的视距范围内,所以我们只考虑电波的视距传播路径,即直射路径和反射路径。本文用反向射线跟踪八叉树算法建立三维传播模型,用MATLAB实现软件编程。该模型首先计算出从发射台站到测试点的所有直射和反射路径并分别计算出其在测试点的场强,将直射和反射路径的场强叠加后可得到测试点的总场强,进一步可计算出发射台站到测试点的总路径损耗。对实地测试数据分析得出,该算法的功率测量误差绝对值小于3dB。利用误差值可以锁定可疑发射台站的范围,减少测试量。
[Abstract]:At present, the transmission test method is used in the testing of radio and television equipment, which affects the normal work and low efficiency of the user equipment. If we can find an effective opening test method, In this paper, three main methods for predicting the propagation characteristics of radio waves are introduced, and the advantages of the deterministic model are explained. Secondly, this paper introduces three commonly used deterministic models and points out that the ray tracing method is widely used in complex urban environments. Several common acceleration algorithms and the reason for using octree partition algorithm in this paper. This paper is to solve the problem of open field testing of radio and television transmission equipment, considering that the selection of test points is generally within the range of sight range of the transmitting station. Therefore, we only consider the line-of-sight propagation path of radio waves, that is, direct and reflection paths. In this paper, a 3-D propagation model is established by using the reverse ray tracing octree algorithm. The software is programmed with MATLAB. Firstly, all direct and reflection paths from the launching station to the test point are calculated and the field strength at the test point is calculated respectively. The total field strength of the test point can be obtained by superposing the field intensity of the direct and reflection paths. Furthermore, the total path loss from the transmitter station to the test point can be calculated. The analysis of the field test data shows that the absolute value of the power measurement error of the algorithm is less than 3dB.Using the error value, the range of the suspected station can be locked and the amount of test can be reduced.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN948.53

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