Research On Massive MIMO Beamforming And Its Application In High-speed Railway Scenarios

With the advent of the modern information age,communication technology occupies a very important position in our daily life,and people have higher and higher requirements for communication quality.The generation and application of massive MIMO beamforming technology have expanded the coverage of communication systems,increased system capacity,accelerated transmission rates,and enhanced transmission reliability.This technology is very consistent with China’s high-speed railway communication industry,which has a huge scale and an increasing demand for communication.Therefore,it is of great practical significance to study the application of large-scale MIMO technology in high-speed rail scenarios.This paper mainly studies the principle,characteristics and application of massive MIMO beamforming technology in high-speed rail scenarios.First,this paper introduces the research background and current status of massive MIMO beamforming technology.Then the basic theory of large-scale antenna array is introduced.Based on the linear array,the relationship between the array far-field electric field and the array element factor and array factor is described.Array factors were deduced separately for several common antenna arrays,and the concept of weighting was introduced.On this basis,the array response matrix of each antenna array was continuously derived,which laid the foundation for the research of beamforming technology.The next step introduces the basic theory of beamforming technology,studies the general system model of beamforming and the criteria for determining the general weights,and selects the most representative maximum signal-to-noise ratio criterion and minimum mean square error criterion for analysis,Showing the general process of beamforming optimal weight formation.In addition,the performance of linear interference constrained minimum variance algorithm(LCMV)and linear constrained feature interference cancellation algorithm(LCEC)in interference suppression was analyzed.Finally,the application of massive MIMO beamforming technology in high-speed rail scene is studied.First,the massive MIMO beamforming model in the high-speed rail scenario is studied.The models of multi-antenna transmission single-antenna reception and multi-antenna transmission multi-antenna reception are described separately.The various parameters of the multi-antenna reception model are implemented in general.Then according to the standard of maximum system capacity,a beam selection algorithm is designed,which mainly determines the optimal beam subset and the number of transmit antennas corresponding to each beam subset according to the train running position.More recently,the advantages of multi-stream beamforming are obvious.When away from the base station,adaptive beam selection can also maintain the maximum system capacity.