Study Of Radio Propagation Based On A Hybrid Algorithm Of Cylindrical Coordinate Parabolic Equation And Method Of Moments

In a wireless communication system,the electromagnetic wave is the carrier of information transmission in the communication system,radio waves propagation is a process of information transmission in communication system,wireless communication quality depends largely on the quality of the information transmission process and in the process of transmission of electromagnetic wave,all kinds of different surface topography,obstacles,limited space and so on will constitute the complex electromagnetic environment of radio waves propagation,so according to different electromagnetic wave transmission environment,it is helpful to establish an efficient wireless communication system to analyze the propagation characteristics of the radio waves between transmit and receive paths of the communication system in advance.Parabolic equation method(PEM)is a kind of deterministic radio wave propagation analysis method based on electromagnetic wave equation.This method can quickly and accurately calculate the radio wave propagation in large-scale space.The traditional parabolic equation method is mainly based on the cartesian coordinate system,which has the problem of limited compute azimuth.Based on the parabolic equation in the cylindrical coordinate system,the electric field change in the omni-directional Angle can be considered in the calculation,compared with the former,the latter is more practical.The method of moments(MOM)is a kind of full-wave electromagnetic analysis method,it have high calculation accuracy and can deal with complicated boundary conditions,but this method exists the shortcoming of large computation,high computing platform requirements,now this method applies only to a small area of radio waves propagation modeling space environment.Based on the advantages and disadvantages of the above two algorithms,this paper proposes a hybrid MOM-PEM algorithm for radio wave propagation modeling in complex scenes,and applies it to radio wave propagation modeling in practical environment.The specific research contents are as follows:Firstly,from the parabolic equation method in two-dimensional rectangular coordinate system,the theory of parabolic equation method was deduced and the Split Step Fourier Transform(SSFT)algorithm has been deduced as well.The influence factors of the error of parabolic equation in the calculation of radio wave propagation are studied,in addition,the results of radio wave propagation by parabolic equation method under different iteration steps are given.Secondly,the solving principles of parabolic equation method in cylindrical coordinate system and method of moments are derived,besides,the propagation process of radio waves in the corresponding scene is simulated.For the radio wave propagation scene with obstacles around the radiation source,a MOM-PEM radio wave propagation hybrid algorithm was proposed.In this method,the modeling of radiation source and near-source obstacle and the strict analytical calculation of radio wave propagation problem are realized in the MOM computing domain.In the PEM computing domain,the cylindrical coordinate system PEM is used for the numerical approximate calculation of radio wave propagation.Compared with full PEM,the hybrid algorithm can directly model the radiation source and near-source obstacles,making the simulation more realistic,compared with full MOM,the hybrid algorithm employ numerical approximation in large area space,which saves a lot of matrix operations and improves the computational efficiency of simulation.Finally,the hybrid algorithm of MOM-PEM is applied to the analysis of wave propagation in complex scenes,mainly include: the near source region contains a finite windowed obstacle,a finite cube obstacle and a semi-closed cube space obstacle.In addition,the hybrid algorithm of MOM-PEM is applied to the analysis of radio wave propagation characteristics in Dedicated Short Range Communication(DSRC)as well.