Research On The Models And Visualization Of Radio Wave Propagation In Mountainous Areas Of Northwest China

With the continuous development of wireless communication technology,wireless communication has become inseparable with People’s Daily life.Wireless communication technology is widely used in broadcasting,telecommunication,navigation and other fields.The frequency characteristics of electromagnetic wave directly determine the transmission distance and coverage range of the signal,meanwhile,it affects the quality and reliability of the signal.Therefore,the characteristics of electromagnetic wave must be fully considered in the design and optimization of wireless communication system to ensure the transmission quality and stability of signals.However,due to the complexity and diversity of electromagnetic wave propagation environment,it is easy to interfere in the propagation process,so it is very important to use the radio wave propagation model to predict it.This paper mainly studies the propagation characteristics of the wireless channel in Lanzhou area by optimizing and modifying the Longley-Rice radio wave propagation model,and verifies the accuracy and adaptability of the correction model in a specific area by comparing with the measured data.Finally,the correction model is used to predict the coverage of the transmitting station,and it is rendered to the map in the form of heat map to realize the visualization of the field strength coverage of the transmitting station.By comparing the measured data with the prediction data of Longley-Rice,Okumura-Hata and Egli models,the Longley-Rice model with the smallest root mean square error is selected as the basic propagation model to study the propagation characteristics of radio waves in Lanzhou area.In order to predict the radio wave propagation characteristics in Lanzhou more accurately,this paper uses a series of methods to modify and optimize the Longley-Rice model.Firstly,the model is corrected by using elevation data for the terrain irregularity of the study area.This can more accurately simulate the propagation of radio waves in complex terrain areas,thereby improving the accuracy of the model.Secondly,the Longley-Rice model does not consider the multipath propagation loss near the receiver,resulting in inaccurate model calculation results.Aiming at this problem,the multipath propagation near the receiver is regarded as the contribution of multiple scatterers to the signal,and then the path loss is calculated to describe the transmission loss of the signal more accurately.Finally,the corrected model is applied to the prediction of radio wave propagation in Lanzhou area.The experimental results show that compared with the traditional Longley-Rice model method,the calibration model and method can effectively improve the prediction accuracy.In order to observe the coverage of the signal of the transmitting station intuitively and clearly,this paper uses Web GIS technology and DEM to generate a three-dimensional map on the browser side,and renders the predicted data corrected by the Longley-Rice model to the three-dimensional map in the form of heat map,so as to better plan the wireless communication network.At the same time,on the browser side,users can customize the location of the launch platform and other related parameters such as antenna polarization,climate type,and the rotation,scaling and translation of the map.Furthermore,users can view the coverage of the transmitting station signal and other related geographic information from different angles and distances.It provides new schemes and ideas for radio communication network optimization and management,and wireless communication network planning,which has important application significance.