Research On Improved Algorithm Of Radio Propagation In Mountain Area

In recent years,with the popularity of geographic information systems,digital maps stored in digital form have been easily accessible.The terrain height,latitude and longitude,etc.on the wireless transmission link that have influence on the radio wave are easily to be obtained through the digital map.In this paper,based on the digital map,combined with the ITU Recommendation to provide the radio propagation prediction model,the following work is done:Firstly,the application of DTED digital map in predicting the propagation loss of radio wave is analyzed.It is possible to determine a radio wave propagation path by selecting the position of the transmission point and the reception point on the digital map and storing the height,the latitude and longitude information of the sample point on the path in txt format for subsequent program calls.Secondly,a variety of radio propagation prediction models are studied and analyzed,including multipath interference model,surface diffraction model,single-edged diffraction,single-rounded mountain model and multi-mountain diffraction model.Then,according to the SEKE algorithm,the corresponding loss model is called under different terrain conditions,after addition,the value is the total propagation loss prediction value of the receiving point.Then,the influence of the antenna height and the operating frequency of the radio wave on the propagation of the radio wave is observed by changing the height of the receiving antenna and the firing frequency of the radio wave.Thirdly,in the multi-mountain model,single-edged model,single-rounded mountain model and Deygout equivalent method are proposed,and a multi-mountain diffraction model for multi-obstacle terrain is proposed.In the case of multiple obstacles in the propagation path,according to the characteristics of terrain and obstacle,a multi-obstacle equivalent method is proposed to improve the computational efficiency.Fourthly,the prediction results of this model and the prediction results of Longley-Rice model are compared with the measured values.It is proved that the model can better reflect the blocking effect of the actual terrain on the propagation of radio waves and provide more accurate prediction result in complex mountain terrain.