GPU-accelerated Ray Tracing Algorithm And Its Application To Radio Channel Prediction In Outdoor Scenarios

In the past few decades,wireless communication has made remarkable and explosive development.The popularity of smart devices continues to promote the rapid development of wireless communications.However,data traffic is increasing day by day,and there is a sharp contradiction between limited spectrum resources and a rapidly increasing system capacity.In order to solve the conflict,people need to continuously design,plan and optimize the wireless communication system in different environments.And it is necessary to study the model of accurately predicting the propagation characteristics of radio waves.As a deterministic model,the ray tracing is widely used to predict the radio wave propagation characteristics,and it can provide accurate prediction results.However,due to the high computational complexity,even for a not so complex geographical environment,such a model is very computationally time-consuming.Therefore,it is particularly important to research,how to use ray tracing to predict the propagation characteristics of radio waves accurately and quickly.In this paper,a reasonable environment modeling is carried out for the outdoor microcell environment.On this basis,the ray tracing is used to realize 2D and 3D radio propagation prediction,and GPU acceleration technology is used to accelerate the calculation of the two algorithms.The research contents and results of the ray tracing in this paper are as follows:1.The research status and theoretical basis of ray tracing are sketched out at first.Then the development of parallel computing technology is introduced.The measurement process of the outdoor channel measurement experiment are described and the algorithm is verified using actual measurement results.2.The research purpose and applicable conditions of the two-dimensional ray tracing algorithm are introduced.Then,a two-dimensional modeling method for outdoor microcell scenes is proposed and a data format for the environment of the outdoor twodimensional ray tracing is designed.To determine the propagation path of the ray,the new virtual source tree is used.Furthermore,the process of implementing the outdoor two-dimensional ray tracing,whose core was the construction of the virtual source tree,is described in detail.And,on this basis,the algorithm is analyzed in parallel,and a parallel algorithm for outdoor two-dimensional ray tracing based on CUDA is developed.The experimental measurement results are used to verify the algorithm.As a result,not only the path loss in the outdoor microcell environment is accurately predicted,but also the prediction efficiency is improved.3.A 3D modeling method is proposed for outdoor microcell scenes.And,a data format that can be used for outdoor 3D ray tracing algorithm to store environmental information is designed.Then,the process of implementing 3D outdoor ray tracing is described in detail.On the parallel analysis of the algorithm,the CUDA-based outdoor three-dimensional ray tracing parallel algorithm is designed,and the parallel algorithm is optimized with multiple GPU technologies.Finally,it not only realizes the accurate prediction of path loss in the outdoor microcell environment,also and improves obviously the calculation efficiency of 3D ray tracing.