Analysis And Simulation Of Diffraction Propagation For Indoor Positioning

Excellent positioning services can enhance the user experience and provide user with intelligent and accurate location information.However,a lot of methods to locate well in outdoor environment,such as UWB,WIFI and Bluetooth,cannot have the same advantages in an indoor environment.This is mainly because the lack in the accuracy of the positioning signal propagation analysis.Therefore,this can also be regarded as a serious challenge to the analysis of the positioning signal.Ray tracing method is an effective method for the analysis of indoor positioning signal propagation.However,the accuracy of the existing ray tracing method cannot meet the requirements of indoor positioning,which is directly related to the influence of diffraction propagation in the process of propagation analysis.Ignoring diffraction in outdoor scenes does not have a great impact on positioning accuracy,but neglecting diffraction in the indoor scenes can cause irreparable damage to the positioning results.Accordingly,the paper design and propose a hybrid model based on the UTD diffraction and indoor multiple diffraction calculation method to enhance the precision and analysis of indoor propagation and to promote the results of indoor positioning accuracy.The main work is as follows:Firstly,the theory and technology of diffraction propagation are studied deeply.Based on UTD(Uniform Theory of Diffraction)and GTD(Geometric Theory of Diffraction),a hybrid model based on UTD is proposed,which is expected to improve the accuracy of indoor propagation analysis and improve the indoor positioning results accuracy.The diffraction mixing model consists of a blended model of diffraction and reflection and a hybrid model of diffraction and refraction.Secondly,we propose and implement the refraction-diffraction model acceleration algorithm to improve the original projection-based decision method founded on the projection.The algorithm based on intersection test and minimum energy detection is therefore proposed to improve the operation of the reflection diffraction model effectiveness.Through the use of intersection test and the angle of the matrix of the integrated application of the algorithm can meet the judgment of the reflection-diffraction model to accelerate the acceleration of the reflection-diffraction model analysis of the operational efficiency.At the same time,this paper also gives a simplified algorithm of the diffraction field strength in the indoor environment and the influence of refraction and reflection on the diffraction propagation in the hybrid model.Finally,on the basis of the hybrid diffraction propagation model based on UTD and the multiple diffraction in the indoor environment,the typical indoor scenes such as the record room are built and the channel simulation is carried out on the scene.Through simulation signal intensity corresponding fading,propagation delay path parameters,and compared these parameters with normal UTD model results and measured results,the necessity of calculation method of diffraction propagation model to verify the accuracy of the proposed indoor and multiple diffraction.