Some Problems About Radio Wave Propagation In 5G Ground Mobile Communication System

Some problems about radio wave propagation in 5G ground mobile communication system are studied in the thesis. The results of the study ha ve the theory and practicality significance for 5G development and research. The main contents are as follows:The opportunities and position of millimeter-wave(mmw) technology in 5G generation mobile communication technology are analyzed. The paper discusses channel model to mmw B-MIMO technology which may be adopted by 5G generation mobile communication in the future. Based on the characteristic of 5G generation mobile communication grid, the key question of radio wave propagation, which is needed to be explored, is summarized.The theoretical models for analyzing atmospheric noise, attenuation rate and theoretical models for calculating additional phase rate of millimeter wave in clear atmosphere and rainy environments are introduced. Combining the smoothly varying space characteristics of atmospheric moisture,atmospheric temperature and atmospheric pressure,at the same time the author consider the characteristics of rain cell height which is 3km-5km and the characteristics of levels range around 13 km in rainy environment, the conclusion that geometric path can take the place of equivalent path in path attenuation of atmospheric environment, modification methods for calculating mmw special attenuation in rainy environment and the value of ha ?va and hb ?vb of electromagnetic waves whose frequency range from 20 GHz to 50 GHz are analyzed and given on the basis of the characteristics of height hypothesis which is less than 100 meters and coverage areas which is less than 500 meters. The question of mmw penetration loss is discussed. Theoretical models for calculating penetration loss and the method of measuring penetration loss are given. The work of studying penetration loss of electromagnetic wave whose frequency range from 11 GHz to 18 GHz is developed. The paper analyzes current state that the leaves shield attenuation. The author studies the blocking loss properties of electromagnetic waves whose frequency range from 11 GHz to 18 GHz.This paper defines the p of the B-MIMO channel on the basis of the research of radio wave propagation characteristics and studies the solution of matrix element of the B-MIMO channel in the clear atmosphere. And it also provides the solution of the p for B-MIMO channel when the terrain features is steady. This paper analysis the distribution of p in the family area of Xidian University by the research method given in this paper. The theoretical method of the solution of channel matrix element is introduced on the basis of known p and multipath propagation. This paper also studies the influence of precipitation particles on the B-MIMO channel and gives the solution of channel matrix element with the rainy environment. Moreover, this paper demonstrates the validity of rainy environment can result in the increasement of p and gives the research method of the influence of dynamic random terrain features on the p and the channel matrix element theoretically.The results in this paper are of certain theoretical meaning and practical value for the research of 5G communication.