Study On Propagation Characteristics Of Indoor Millimeter Wave Wireless Channel Based On Ray Tracing Method

The fifth generation mobile communication system requires higher transmission rate and bandwidth.The shortage of spectrum resources also promotes the development and application of MMW frequency band.The millimeter wave has short wavelength and wide frequency band,which has become a research hotspot in the fifth generation mobile communication system.This paper summarizes the current research hotspots and research status of millimeter wave,and based on SBR/FDTD hybrid method,carries out simulation research on the channel characteristics of millimeter wave in indoor propagation environment.Firstly,this paper summarizes the basic characteristics and research status of millimeter-wave,and expounds the propagation mechanism of millimeter-wave,the basic theories of ray-tracing method and FDTD method used in simulation,as well as the common channel measurement methods used in actual millimeter-wave measurement.Secondly,the actual measurement and simulation analysis of the millimeter wave propagation characteristics in the line-of-sight and non-line-of-sight paths are carried out,and the results are compared with those in the existing literature,which verifies the correctness and feasibility of the study on the millimeter wave propagation characteristics based on the mixed method of SBR/FDTD and REMCOM software.On this basis,the simulation analysis of the millimeter wave in the transmission characteristics of large indoor exhibition hall,compared the different depths of channel parameters,the simulation and compare of electromagnetic wave propagation under different spectrum analysis,and the simulation analysis using different materials to the influence of the millimeter wave propagation channel,the simulation results show that:(1)using four reflection,one transmission and a diffraction simulation depth,can take into account the simulation speed and precision.(2)with the increase of frequency band,the path loss increases successively,and the spread of root mean square delay presents a downward trend,which indicates that MMW is suitable for indoor short-distance communication scene.(3)when the material with a relatively small dielectric constant is used,the received power will be improved and the delay extension will be reduced.Then,the simulation analysis of the millimeter wave in the transmission characteristics of the indoor lab environment,and compare the analysis with different polarization modes of channel parameters,and analyzes the influence of different surface roughness on the propagation characteristics of millimeter wave channel,the transmitter were studied using different antenna number of linear array antenna on the effects of delay spread,the simulation results show that:(1)the circular polarization in the stadia scenarios can effectively reduce the delay spread,to improve the receiving performance;(2)in the case of line-of-sight,the increase of roughness can effectively reduce the delay expansion;In the case of non-line-of-sight,the roughness has little effect on the time delay expansion.(3)with the increase of the number of antennas in the array,the mean mean of root mean square delay extension shows a decreasing trend,indicating that the increase of the number of antennas can reduce the multipath fading of the channel.Finally,based on the double indoor residential environment,the simulation analysis of the millimeter wave propagation across the floor when the channel,as well as the different channel characteristics of transmitting antenna height,and millimeter wave is studied based on the K-means algorithm clustering features,proved that the multipath component widely exist in millimeter wave propagation and clustering characteristics of the launch Angle and arrival Angle.