Study On Characteristics Of Large-scale Antenna Wireless Transmission Channel Based On UMa Scenario

As a new generation of wireless communications technology,high-speed, high-quality is the main research objectives of 5G. The large-scale multi-antenna technology has become one of the most important key points. Compared with the traditional MIMO(Multiple-input Multiple-output) technology, large-scale multi-antenna technology can greatly improve the channel capacity, spectral efficiency and power efficiency. In addition, large-scale multi-antenna technology can significantly reduce the air interface delay, simplify the multiple access layers, improve robustness against unintentional human interference and intentional interference. Although large-scale antenna technology can bring high spectral efficiency, Several challenges are emerging along with the use of very large antenna arrays, such as channel modeling, pilot sequences design, channel state information (CSI)estimation, and so on. As we all know, the channel in the whole process of communication is a very important part. The characteristics of the channel are related to the communication capability and the quality of the service of the wireless communication system. By measuring the propagation process of the wireless channel in space, the propagation characteristics of wireless on-demand can be summarized, and the corresponding propagation model can be established. The accurate channel model plays an important role in calculating the network design parameters, studying the corresponding wireless receiving technology and developing the resources in the time domain. In this paper, large-scale multi-antenna channel is studied and analyzed based on the measurement results of real environment. The main work includes :At the beginning, the rationality of large-scale multi-antenna virtual measurement is validated. In this paper, the rationality of large-scale multi-antenna virtual measurement is verified based on the 3.5 GHz band in the urban macro-cell scenario and the whole process of virtual measurement is discribed, including the data processing and the scheme of combining the antennas. In the verification of large-scale multi-antenna virtual measurement rationality, the whole verification process is divided into two parts for analysis. In the time domain, the power delay profiles in the virtual measurement and practical measurement are compared. The same spot and the same measurement environment are guaranteed during the meansurement. In the spatial angle domain, the angular power distribution of the signals in the virtual measurement and the field measurement is discussed respectively. And the distribution of the two methods of measurement results were compared and analyzed. The results of the rationality of virtual measurement are given.Second, the characteristics of large-scale multi-antenna channel in urban macro-cell scene is analyzed. In this paper, the different bandwidths of the 3.5 GHz band are measured in the urban macrocell scene, and the results are processed and analyzed. In terms of time domain, the paper focuses on the analysis of the time-dispersion parameter, namely the time-delay spread in large-scale multi-antenna channel. Correspondingly, in the spatial angle domain, the spatial dispersion parameters, ie angular spread, are analyzed in a large-scale multi-antenna channel. And the specific parameters are compared with the reference values in the 3 GPP literature in the time domain and the space domain, respectively. In terms of capacity, the change of capacity and the difference of capacity under different bandwidth are compared.By comparing different bandwidths, different scenes and different antenna numbers, the corresponding conclusions are obtained, and some basic laws of eigenvalue distribution in large - scale antenna system are also found.