Research On Radar-Aided Channel Estimation And Beamforming Algorithms For Millimeter Wave Massive Mimo Vehicular Networks

The millimeter wave massive MIMO system can overcome the strong path loss by being equipped with a large antenna array,which can significantly improve the energy efficiency and spectrum utilization of the system.However,the high mobility of vehicle users in the vehicular networking system and the short-distance transmission of largescale millimeter wave antenna arrays have made channel estimation and beamforming for millimeter wave massive MIMO vehicular networking communication more challenging.Radar system has been proved to play an active role in millimeter wave massive MIMO communication system because of its easy processing and real-time performance.This paper focuses on the channel estimation and beamforming design problems of millimeter wave massive MIMO Internet of Vehicle and conducts the following research.Firstly,in order to solve the problems of fast and frequent channel switching,doppler shift and high-dimensional channel calculation complexity of millimeter wave massive MIMO vehicular networking communication system,a radar aided channel estimation scheme based on tensor is proposed.The radar is used to assist the estimation of the channel angle of arrival and angle of departure accurately and efficiently.The massive MIMO multi-dimensional received signal is expressed as a low-order tensor,thereby the fast fading channel gain is accurately estimated.The simulation results show that the proposed channel estimation scheme compared with other algorithms is more accurate in high mobile environment.Secondly,in order to solve the problem of frequent channel switching of the millimeter wave massive MIMO Io V communication system and the computational complexity of high-dimensional received signal processing,a radar assisted millimeter wave massive MIMO vehicular networking hybrid beamforming design scheme based on tensor is proposed.The massive MIMO multi-dimensional received signal is expressed as a low rank tensor,and the factor matrix obtained by tensor decomposition as well as the real-time space angle information estimated by radar is used to design the hybrid beamforming matrix to reduce the interference between users.The simulation results show that compared with other algorithms,the proposed hybrid beamforming scheme has better performance in terms of system spectral efficiency and bit error rate.Finally,according to the discussion of channel estimation and hybrid beamforming design of millimeter wave massive MIMO vehicle networking in the first two chapters and the proposed corresponding algorithms,a real test scenario is constructed to analyze the performance of these algorithms more accurately in various road traffic conditions,meteorological environment and various use scenarios.The test results and theoretical analysis prove that the proposed channel estimation and beamforming method can effectively improve the performance of the entire millimeter wave massive MIMO Io V communication system.