| With the rapid development of wireless communication technology as well as the increasing demand for high-speed data service,improving system throughput is still an important goal of wireless mobile communication.Multi-antenna technology which can effectively reduce interference and significantly improve the spectral efficiency by beamforming,has become a hot technology in the field of communications.The study of MIMO technology is developed from two dimensional space to three dimensional space,from small scale MIMO to large scale MIMO.3D MIMO technology can reduce the interference and improve system performance by increasing the vertical dimension and beamforming in the horizontal direction and the vertical direction.Large scale MIMO technology can significantly increase throughput by installing hundreds of antennas at the base station and sending datas over them at the same time.The main contributions and innovations are as follows:Firstly,according to the relevant protocols proposed by the 3GPP organization,the paper includes the channel modeling for different application scenarios in the millimeter-wave and finishes the first and second stages of the 3GPP 5G NR calibration.Secondly,the hybrid beamforming technology can solve the problem of complex structure caused by too many antennas in a large-scale MIMO system.This paper presents a multi-level codebook design method,which can ensure system spectral efficiency and reduce the complexity of the hardware implementation.Finally,in the large-scale MU-MIMO system,this paper proposes a multi-user transmission scheme based on antenna panel.The method uses multi-user pairing and proportional fair scheduling algorithm to complete the system performance evaluation of different schemes.The system simulation results come to the conclusions:(1)Antennas are mapped to different ports with different vertical dimensions.The results prove that 3D MIMO can provide better performance than 2D MIMO.In addition,the performance improvement is much larger for MU-MIMO than SU-MIMO.(2)In large-scale MIMO systems,antennas are mapped to di:fferent panels.The results prove that the hybrid beamforming's pectral efficiency is not much different from that of the full digital beamforming.And different mapping methods affect the system performance.(3)Large-scale MIMO technology is applied to the millimeter-wave scenario,and both the base station and the user adopt hybrid beamforming method.Compared with single-user scheme,multi-user scheme can effectively improve the system throughput and reduce the probability of user interruption.(4)By modeling the SRS error,the SRS error has a greater performance loss on the MU-MIMO system than the SU-MIMO system. |
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