Vector Measurement And Calibration Of Transmission Parameters In Broadband Microwave Network For 5G Channel Measurement System

The acquisition of channel state information(CSI)is very important to give full play to the performance of 5G communication system.Therefore,how to accurately measure and evaluate CSI is one of the research focuses of the new generation of mobile communication technology.However,the frequency bands used in traditional mobile communication technology are below 6GHz,and a large number of channel model research results have been accumulated in these bands.Therefore,how to accurately acquire CSI in higher frequency band has great research value,and the measurement and calibration of channel transmission parameters is an important part of acquiring CSI.This thesis designs a measurement and calibration scheme for 5G channel measurement system.The system is to solve the technical problems faced by the future mobile communication system,such as accurate acquisition of higher frequency CSI,accurate measurement of multi-channel broadband correlation signals,accurate establishment of multi-dimensional channel model and so on.The main work and innovative achievements of this thesis are as follows:1.The basic hardware architecture and measurement principle of the 5G channel measurement system are analyzed.The error factors affecting the measurement accuracy of the system are analyzed,and the system error model is established.According to the error model,two system measurement schemes for evaluating the measurement accuracy of the system are designed,and the influence of timing synchronization error on the measurement results is analyzed.An experimental platform is built to verify the scheme.2.Two channel measurement schemes,frequency domain measurement and time domain measurement,are designed,and the relationship between time domain response and frequency domain response is deduced.A calibration scheme is designed for frequency domain measurement,and an experimental platform is built to verify the scheme.The amplitude error is less than 0.5d B compared with the test results of vector network analyzer.The phase error is less than 3 degrees.For the time domain measurement,the measurement results are compared with the theoretical results,and it is found that they are basically consistent with the theoretical results.Both schemes can meet the measurement requirements of 5G channel measurement system.3.The calibrator used in the measurement and calibration scheme,UWB quarter power divider,is designed.The influence of power divider performance index on measurement error is analyzed.The design and simulation process of power divider,CST simulation model and simulation results are given.The working frequency band of the power divider is 2GHz-18 GHz,the port isolation is better than 15 d B,the amplitude balance is better than 0.5d B,and the phase balance is better than 3 degrees.The output of the four ports of the power divider has good amplitude and phase consistency.