山区环境电波传播预测的改进算法研究

发布时间：2018-06-15 00:27

本文选题：无线电波 + 路径损耗　；参考：《南京邮电大学》2017年硕士论文

【摘要】：近年来,随着地理信息系统的普及,以数字形式存储的数字地图已方便获取,通过数字地图可以方便获取无线传播链路上的地形高度、经纬度等对无线电波传播有影响的地理因素。本文基于数字地图,结合ITU建议书提供的电波传播预测模型,完成了以下工作:第一,分析研究了DTED格式的数字地图在预测无线电波传播损耗中的应用问题。能够通过在数字地图上选定发射点与接收点的位置确定一条无线电波传播路径,并将此路径上样本点的高度、经纬度信息使用txt格式存储,以便后续程序调用。第二,分析研究了多种电波传播预测模型,包括多径干涉模型、地表绕射模型、单刃峰模型、单圆峰模型和多峰模型。然后根据SEKE算法,在不同的地形条件下调用对应的损耗模型,叠加后计算在接收点的总传播损耗预测值。并且通过改变接收天线的高度和无线电波的发射频率来观察天线高度和无线电波的工作频率对电波传播的影响。第三,在多峰模型中,结合了单刃峰模型,单圆峰模型和Deygout等效法,提出了适用于多障碍物地形下的多峰绕射模型;在传播路径上有多个障碍物时,根据地形和障碍物的特点,提出了多障碍物合并等效计算法,提高了计算效率。第四,将本文模型的预测结果与Longley-Rice模型的预测结果和实测值进行对比分析,验证了本文模型在复杂的山区地形中能够更好地反映实际地形对电波传播的阻挡效应及提供更精确的预测结果。
[Abstract]:In recent years, with the popularity of geographic information systems, digital maps stored in digital form have been easily obtained, through which the terrain height on wireless communication links can be easily obtained. Geographical factors affecting the propagation of radio waves, such as latitude and longitude. Based on the digital map and the radio wave propagation prediction model provided by ITU recommendation, this paper completes the following work: first, the application of digital map in DTED format in the prediction of radio wave propagation loss is analyzed and studied. A radio wave propagation path can be determined by selecting the position of the transmitting point and the receiving point on the digital map, and the height, longitude and latitude information of the sample point on the path can be stored in txt format for the subsequent program to call. Secondly, a variety of radio wave propagation prediction models, including multipath interference model, surface diffraction model, single-edged peak model, single-circular peak model and multi-peak model, are analyzed and studied. Then, according to the SEKE algorithm, the corresponding loss model is called under different terrain conditions, and the total propagation loss prediction value at the receiving point is calculated after superposition. The influence of antenna height and radio wave operating frequency on the propagation of radio wave is observed by changing the height of the receiving antenna and the transmitting frequency of radio wave. Third, in the multi-peak model, combining the single-edged peak model, the single-circular peak model and the Deygout equivalent method, a multi-peak diffraction model suitable for the multi-obstacle terrain is proposed, and when there are multiple obstacles in the propagation path, according to the characteristics of the terrain and obstacles, An equivalent method of combining multiple obstacles is proposed, which improves the efficiency of calculation. Fourthly, the prediction results of this paper are compared with those of Longley-Rice model and the measured values. It is verified that the proposed model can better reflect the blocking effect of the actual terrain on the propagation of radio waves and provide more accurate prediction results in the complex mountainous terrain.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN011

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