Millimeter Wave Beamforming And Beam Tracking For High Speed Mobile Platforms

Millimeter wave is defined by the International Telecommunication Union(ITU)as a candidate frequency for the fifth generation of mobile communication because of its high frequency point and large bandwidth.Meanwhile,UAVs will be a typical business scenario of the fifth generation of mobile communications.Therefore,this thesis will focus on the research of the UAV platform for the fifth generation mobile communications.There are three mainly contributions in this thesis:(1)In order to solve the problem of high complexity and large overhead in pre-coding matrix of hybrid beamforming in large-scale array antennas,the sparse characteristics of millimeter-wave channel transmission are explored,and the characterization method of millimeter-wave channel sparsity is proposed.Combined with the mathematical tools of compressive sensing,the Orthogonal Matching Pursuit(OMP)was used to solve the target hybrid precoding matrices,and the algorithm overhead was reduced from the theory O(Nt2)to O(NtRF);(2)In order to improve the robustness of UAV beamforming under different moving conditions,the UAV moving state motion parameters are taken as the observed noise of Kalman filter algorithm,and the observation results are iteratively corrected to ensure the UAV beam tracking performance.The simulation results show that,compared with the traditional low frequency band tracking algorithm,the Kalman filter-based millimeter-wave beam tracking algorithm has good performance in reducing the algorithm overhead at O(a log(?t))and reducing the tracking error at E(?2);3)Aiming at the capacity increase of multi-cluster communication system in airborne UAVs in millimeter-wave frequency band,the inter-beam interference of UAV terminal are taken into consideration as the factors of system capacity.The mechanism of dynamic iterative beam and power allocation vector is proposed to reduce the influence of inter-beam interference on system capacity improvement and improve the spectral efficiency of UAV system to 50%.In the end,the thesis summarizes the research involved,and proposes the planning and direction for the next step.