Study On Millimeter Wave Channel Propagation Characteristics In Indoor Environments Based On Ray Tracing Method

The Fifth-Generation Mobile Communication System puts forward new requirements for transmission rate and bandwidth.The spectrum below 6GHz is approaching saturation,and the development of high frequency band is imperative.Millimeter wave has the characteristics of short wavelength and wide frequency band,which is suitable for indoor short-distance high-speed communication and becomes the key technology and research hotspot of the next generation communication system.This paper firstly summarizes the current research status and existing achievements of MMW,expounds the theoretical basis of ray tracing method used in simulation,the measurement system and method used in MMW channel.Based on ray tracing method,this paper simulates and analyses the propagation characteristics of indoor MMW channel.The specific research contents and innovations are as follows:(1)The classical indoor LOS and NLOS environment are simulated and analyzed based on ray tracing method,determine the best values for calculation depth,by comparing the simulation results in this paper with the measurement results in existing literatures,the correctness and applicability of the MMW propagation research based on the ray tracing method in this paper are proved.The transmission characteristics of different materials of MMW are compared,and each path of transmission and reflection is studied through power delay spectrum,it can be known which material characteristics are more conducive to the MMW propagation.(2)The received power,path loss and RMS of 28 GHz MMW in indoor complex multi-layer environment are studied.Based on the analysis of MMW propagation modes and channel characteristics between different floors,a method to improve the quality of MMW propagation between different floors is proposed.Then,the directivity and polarization characteristics of the transceiver are changed in the single layer indoor environment,and the received power,RMS and other channel parameters are simulated and compared.Through the comprehensive analysis of CDF,the propagation characteristics of different antennas with different settings in indoor LOS and NLOS environments are summarized and suggestions are given.(3)Finally,based on the simulation of 28 GHz MMW in the basement environment,the characteristics of MMW angle and multipath clustering are analyzed by combining the power delay distribution.The variation of channel parameters at different transmitting antenna heights is analyzed.The study provides a favorable reference for transmitter placement in indoor environment.In order to study the clustering characteristics of MMW,the multi-path distance component MCD is introduced.Compared with the traditional clustering algorithm,the K-means++ algorithm with better clustering effect is proposed for multi-path component clustering.According to the KP index,the optimal number of clusters in different environments is determined.By analyzing the multi-path angle clustering pattern of directional and omnidirectional transmitter,the clustering characteristics of MMW propagation are proved,and the clustering characteristics of DOD and DOA are summarized.