The Propagation Characteristics And Modeling Of 28 GHz Millimeter-wave In Indoor Environment

The 21 st century is the information age,and the birth of various mobile terminal devices has generated a large number of wireless data traffic,resulting in the extreme lack of the low frequency spectrum resources of below 6 GHz.The Fifth Generation mobile communication will introduce millimeter wave,which can provide high speed data connection for hot spots.As one of the alternative frequencies of 5 G millimeter-wave,28 GHz has become a research hotspot because its propagation characteristics and modeling in different environment are critical to the planning and operation of 5 G systems.This thesis presents the study of the propagation characteristics and modeling for 28 GHz millimeter wave from simulations and measurements.Three typical indoor channel environment are studied for 28 GHz millimeter wave radio propagation characteristics,and the parameters of large scale path loss model are determined.The research aspects and contributions are as follows:(1)For the characteristics and the transmission mechanism of radio wave propagation,the thesis has conducted the thorough research,besides the measurements and modeling methods of various channel environment for a variety of alternative frequency of global 5 G millimeter wave.Based on the LabVIEW,a set of self-design 28 GHz wireless channel measurement system is presented,which can achieve the display and preservation of the measured real-time data,meanwhile monitoring the environmental temperature,humidity and pressure.(2)A large scale path loss model is constructed based on Close-In free space reference distance path loss model and Floating-Intercept path loss model.The indoor corridor environment is modeled and simulated by a simulation software Wireless Insite which is based on the Shooting and Bouncing Ray/Image method.By the Direction Scan Sounding method,the 28 GHz large-scale path loss was measured,then using the Minimum Mean Square Error fitting simulation and measurement data,based on the Close-In free space reference distance path loss model,the simulation the measured path loss exponent n is 1.07 and 1.25,respectively,based on the Floating-Intercept path loss model,measured n is 1.85.At the same time,the simulation n of 2.4 GHz are 1.41 and 1.6,and the measured n is 1.44 and 1.35 based on the FI model and CI model.(3)The effects of several cases on path loss were studied,including the antenna polarization characteristic and the position,the room furniture,reflective aluminum palte,double insulation glass and the human body.It is found the path loss of the Cross-polarization is greater 30 dB than the Co-polarization,when the distance between transmitting antenna and sidewall are the 1.25 m,0.8 m,0.4 m,n is 1.25,1.74 and 1.91,respectively.The study shows that the transmission loss of double insulation glass increases with the incident distance and incidence angle of the vertical polarization wave,the average transmission loss within 40 cm is 24.87 dB.In addition,the aluminum plate can increase the intensity of the signal strength in NLOS to the same intensity as LOS in the same distance,the average loss of the human body signal protection is 4 dB.