| With the extensive deployment of 5G mobile Internet and Internet of Things.massive 5G terminals have rapidly entered people’s production and living,the acquisition of 5G terminal location information has increasingly become an indispensable service requirement.The terminal localization system using radio technology usually includes two core problems:the acquisition of physical information for observation and the design of location algorithm for position solutions.The physical observation information mainly includes the information that characterizes the propagation characteristics of the wireless channel,such as the received power.propagation time,and arrival angle of the radio wave.It can be seen that the characteristics of the wireless channel have a fundamental impact on the performance of the localization system.A comprehensive understanding of the wireless channel is needed to improve the accuracy of localization system.As most existing research on wireless channel measurement and channel modeling focuses on addressing the requirement of mobile communication systems,There are few attempts to study the wireless channel model in terminal localization scenarios.Aiming at 5G terminal localization applications,this thesis studies wireless channel propagation characteristics in typical application scenarios based on wideband channel measurement.The results have important guiding significance for supporting the development of the 5G terminal localization system,realizing and optimizing the core localization algorithm.The main contents of this thesis are summarized as follows:(1)Analysis and modeling of channel characteristics in indoor-to-indoor scenarios for terminal localization.In indoor scenarios,wireless channels present complex time-varying and fluctuation characteristics due to deep multipath fading and non-line-of-sight propagation.In this thesis,wideband channel measurements are carried out to investigate the characteristics of indoor-to-indoor channel.Based on the raw data,a statistical model of large-scale and small-scale channel characteristics,including path loss,delay spread,and angle spread is established,and gives the statistical table of parameters.In addition,an indoor-to-indoor building penetration loss model is studied based on measurement in the case of the same layer and cross-layer of the transceiver,and the relevant results can provide reference for the design of indoor positioning system.(2)Analysis and modeling of channel characteristics in indoor-to-outdoor scenarios for terminal localization.The propagation characteristics of wireless channels in indoor-to-outdoor scenarios are closely related to the environment at the receiver.Fewer channel measurements and characterization results are available.In this thesis.wideband channel measurements are carried out to investigate the characteristics of indoor-to-outdoor channels.Statistical models of channel characteristic parameters,such as path loss,delay spread,and angle spread are established.In addition,a measurement-based indoor-to-outdoor building penetration loss model is studied,and the modeling results are compared with the reference model provided in the standard.(3)Analysis of localization error based on channel measurement for terminal localization.Different from the mobile communication systems,which take the bit error rate of the received data stream as the performance index,the localization systems focus more on investigating the estimated position error.Based on the channel measurement results,this thesis studies the time difference of arrival(TDOA)calculation methods between different measurement spots and terminals.Then,the localization error in indoor-to-indoor and indoor-to-outdoor scenarios are compared and analyzed based on the defined two kinds of error analysis methods. |
