Simulation And Measurement Of Millimeter Wave Propagation Characteristics In Complex Tunnel Environment

In recent years,with the increasing demand for communication quality,the research of the fifth generation wireless communication system is progressing rapidly,and the propagation characteristics of millimeter-wave has become one of the hotspots in the field of communication.As an important place of modern society,the study of the characteristics of millimeter wave propagation in tunnels takes important practical value and theoretical significance.In this thesis,the propagation characteristics of millimeter wave in tunnel environment are studied based on the method of Shooting and Bouncing Ray/Image,and the measurement and simulation of millimeter wave wireless channel are carried out,which provides a theoretical basis and scientific support for the network planning and optimization in the tunnel environment,for the millimeter wave communication of next generation.The main contents of this thesis are as follows:(1)In this thesis,the research status of millimeter wave is introduced firstly.Then,the basic concept and implementation algorithms of the method of Shooting and Bouncing Ray/Image are introduced.Furthermore,the hardware system and measurement steps used in the measurement are explained as a significant part.(2)To verify the correctness of this method: modeling and simulating in a typical rectangular straight tunnel environment,the simulation results are compared with the measured results in the literature.On this basis,the propagation characteristics of millimeter waves in the tunnel environment with different roughness conditions were compared.The actual measurements of complex tunnel environments with straight line-of-sight conditions and bending non-line-of-sight conditions are carried out,while the simulation modeling is also carried out.Then,the simulation result are compared with the measured result.(3)To consider the diversity of simulation conditions: the influence of different radius of curvature on the propagation characteristics of millimeter wave in curved tunnel is discussed.While the difference between vertical polarization and horizontal polarization in curved tunnel is compared.Then,the difference of the propagation characteristics and the root mean square delay of the vertically polarized waves in different situations are compared by simulation.The propagation characteristics of the three different radii are compared and analyzed.(4)To consider the feasibility of simulation environment: the propagation characteristics of millimeter wave are simulated in complex tunnel environment with vehicles inside.The effects of different number of vehicles and vehicles in different positions on the millimeter wave propagation are analyzed,while the effects of the received power and the Doppler shift are discussed.