Research On 3D MIMO Propagation In O2I Scenario Based On Measurement

In response to the explosive growth of wireless data services, the Fifth Gen-eration mobile communication system (5G) comes into being. 3D MIMO tech-nology and Massive MIMO technology are in hotspot. In addition, 021 is a kind of scenario, which communication coverage is from outdoor BS and some indoor accesses cannot be established, that need communication from outdoor to cover indoor. Moreover, the vertical dimension can be utilized in 021 scenario, greatly improving the channel transmission rate, so 021 channel in real life represents an increasingly significant use case. In this thesis, the propagation statistic charac-teristics of 3D MIMO channel are studied based on the data of channel measure-ment in 021 scenario. On the basis of 3D MIMO, the virtual Massive MIMO channel is simulated by the method of translating the antenna in base station, and the influence factors of channel performance are analyzed. Specific research points are as follows:(1) The channel measurement of 3D MIMO channel in 021 scenario is car-ried out and propagation statistic characteristics are analyzed. In the 021 scenario,the height of the floor where the receiver is located will affect the propagation characteristics of the 3D MIMO channel. 3D MIMO technology can use the ver-tical degree of freedom in the 3D space to make full use of the limited spectrum resources, eliminate the interference between the users and it is of great im-portance to enhance the service of the system and spectral efficiency. In this thesis,we first analyze the delay spread of 3D MIMO channel in the 021 scenario, we can make a conclusion that in the case of LOS, the closer the receiving antenna is to the transmitting antenna in the vertical dimension, the larger the delay spread is. However, in the NLOS case, the closer the receiving antenna is to the transmit-ting antenna, the smaller the delay spread is. It is also found that the angle spread of the horizontal dimension of each measurement floor is larger than that of the vertical dimension, and the closer to the antenna of the transmitter, the smaller the angle spread is. Then, according to the spatial correlation, the channel capacity of the receiving antenna at different floor is analyzed to find the correlation between the antenna height and the channel capacity.(2) Constructing a virtual large-scale antenna to carry on channel measure-ment and analyzing the channel performance. As one of the key technologies of future 5G, Massive MIMO is the hot attention of the industry recently. Due to the high cost of large-scale antenna, the recent channel measurements are done usu-ally through combining the single antenna into a virtual large-scale antenna. In this thesis, the propagation characteristics of the channel are studied by construct-ing a virtual 256-antenna array element through translating the uniform planar array (32 elements). First, we analyze the influence of measurement's bandwidth on the propagation performance. We find that the channel capacity of 100 MHz bandwidth is not very different from the 200 MHz bandwidth through the study of channel capacity. When the signal bandwidth is changed from 100 MHz to 200 MHz, the delay spread of the channel does not change much. Another found is that the channel capacity of the system will increase with the increase of the num-ber of base stations, but the rate of the growth will decrease and eventually reach the capacity limit due to the number of user. In addition, in the antenna spacing analysis, it can be found that the increase of antenna spacing can bring greater capacity gain through the comparison of different antenna spacing, and the change of antenna spacing in horizontal dimension has more influence on the system per-formance.In summary, this thesis is focus on the key technology of 5G, 3D MIMO and Massive MIMO, studying channel propagation characteristics and performance based on O2I scenario channel measurement data for the 5G system. It is hoped that these results will be helpful to the standardization of channel and the research of new technology.