Large-scale Parallel UTD Calculation Of Urban Electromagnetic Environment

Urban electromagnetic propagation predictions are generally divided into two types: one is based on statistical methods of measurement data,and the other is based on deterministic methods of ray theory.With the rapid development of modern cities,the urban threedimensional environment changes rapidly,which leads to the lack of statistical similarity between urban scenes,so the statistical methods are no longer applicable.The ray tracing technology is to simulate the modeling of urban buildings,so that the propagation of radio waves can be described by a certain ray tracing process,so that the characteristics of radio wave propagation in urban environments can be accurately calculated.In the application of ray tracing technology,the ray tracing process is usually the most complicated and time consuming process.This paper combines the higher order moment method(Higher-Order Mo M,HOMo M)with the Uniform Geometrical Theory of diffraction(UTD).The high and low frequency hybrid algorithm establishes the urban propagation model,parallelizes the ray tracing process in the urban scene,and transplants the parallel program to the cluster system,thereby greatly accelerating the calculation speed while ensuring the calculation accuracy.By using HOMo M to perform full-wave accurate simulation of the antenna system,UTD is used to perform fast ray tracing on large size targets,and an interface is established between the two algorithms to quickly solve complex and large size under the premise of ensuring calculation accuracy.On the basis of this,using MPI parallel programming technology,aiming at the similarity of the ray types of adjacent observation points in the urban ray tracing process,a parallel strategy based on the alternate allocation of observation points is proposed to reduce the calculation amount.The resulting load imbalance is affected and efficient parallel efficiency is achieved.Finally,the actual measurement is carried out on a certain area and a certain cell,and the comparison results between the measured data and the simulated data are given.The comparison results show that the method can quickly and accurately calculate the propagation characteristics of the electric wave in the urban scene.