Research On The Theory And Application Problems Of 3D-MIMO

3D-MIMO technology is one of the key technologies of 5G,which opens the door to the vertical dimensional freedom for the traditional MIMO technology.By adaptation of the beams in vertical direction,it is possible to extend the coverage of users in high-rise buildings,track the terminals in the vertical plane in densely-spaced scenes,and reduce the interference to neighboring cells.Space-division multiplexing in the vertical plane can also be implemented to improve spectrum efficiency.This paper firstly studies the application scenarios and the key technologies of 3D-MIMO.Then,a 3D-MIMO simulation platform was established to evaluate the system performance of 3D-MIMO,laying the foundation for further researches.With the development of mobile communication technology,spectrum resources have become scarce.Most mobile network operators in the world need to deploy multiple antenna systems of different frequency bands in the same base station.In order to improve the utilization rate of Antenna installation environment resources,realize the miniaturization of the base station antenna and achieve the purpose of beautifying the antenna at the same time,a multi-frequency coaxial antenna is considered to be developed in the engineering application.The current multi-frequency coaxial units are involved in the frequency range of several octaves.However,with the development of 3D-MIMO technology,the shared caliber of the active antenna port and the passive antenna port may be involved.In this paper,a scheme of coaxial design with C-band and Sub-2.6GHz is proposed to support the active antenna port in the C band and the passive port in the Sub 2.6GHz band,in order to support the operators'compatibility with the two technologies.In this paper,the relevant parameters of the program,the way the antenna components arrayed and the system performance are simulated,supporting for engineering applications.Due to the scarcity of spectrum resources,except that the same base station supports two bands with large difference at the same time,there are two different wireless communication systems deployed adjacent channels in adjacent physical areas in practice.In this case,adjacent channel interference arises.Much of the current research only deals with LTE systems with a single antenna.Due to the changes of the spatial distribution of signals in 3D-MIMO system,adjacent-frequency interference needs to be re-evaluated.In this paper,the influence of the increase of the antennas numbers on the ACLR index is studied.We also evaluate the influence of the correlation between the transmitted signals on the adjacent frequency interference,which provides the direction for reducing the adjacent frequency interference between 3D-MIMO systems.