Research On The Propagation Characteristics Of Indoor Millimeter Wave Channel Based On The Measurement Methods Of Frequency-Domain And Time-Domain

At present,the fifth-generation mobile communication system(5G)has been put into commercial use.Millimeter wave technology has become a research hotspot because it can meet the data transmission requirements of 5G due to its wide frequency band,low latency,and high speed.Due to the high loss characteristics of millimeter waves,it is suitable for indoor short-distance wireless communication.Moreover,the propagation characteristics of radio waves are highly sensitive to the scenario,thus it is urgent to carry out research on the propagation measurement and propagation characteristics of millimeter-wave channels at different frequency bands in different indoor application scenarios.Taking into account the advantages of frequency-domain and timedomain measurement methods,actual measurement of millimeter wave channels in different indoor scenarios and different frequency bands are conducted in this thesis.In addition,the shooting and bouncing ray/image(SBR/IM)method are used for simulation.The simulation results and the measured results were compared and analyzed.And the propagation characteristics of indoor millimeter-wave channels are studied.The main research contents of this thesis are as follows:(1)The research status of millimeter-wave channel frequency-domain measurement,timedomain measurement and ray tracing simulation is summarized.The propagation mechanism of millimeter wave and the theory of SBR/IM method are introduced.The advantages and disadvantages of the frequency-domain and time-domain measurement methods of millimeter wave channels are compared and analyzed,and the technical route of channel parameter extraction based on the frequency-domain and time-domain measurement methods is elaborated in detail.(2)Based on the frequency domain measurement method,which has the advantage of covering a wide measurement frequency band,the frequency domain scanning method is used to measure the wireless channel in indoor corridors and office scenes,and the ray tracing simulation is carried out.The frequency-domain test system and the settings of the simulation parameters are expounded in detail,and the simulation results and the measurement results are in good agreement.The feasibility and correctness of the prediction of indoor millimeter-wave channel propagation characteristics based on SBR/IM method are verified.The large-scale fading and small-scale fading characteristic parameters of indoor corridor and office scenes are effectively extracted by the frequency domain measurement method.(3)Based on the time-domain measurement method,which has the advantages of being fast and efficient,the time-domain correlation method is used to measure the wireless channel in complex teaching and research room environment,and the ray tracing simulation is carried out.The timedomain measurement system and simulation parameter settings are described in detail.And the highresolution space-alternating generalized expectation maximization(SAGE)algorithm is used to analyze the characteristics of the channel propagation parameters.Based on the time-domain measurement method,the channel propagation parameters such as path loss,received power,power delay profile,multipath delay,and angle distribution can be effectively extracted in complex teaching and research room environment.