Research Of Three Dimensional MIMO Technique In LTE-Advanced System

MIMO (Multi-Input Multi-Output) and Enhanced MIMO technology can effectively improve the capacity performance and coverage performance of LTE-Advanced system. In the standardization process of LTE-Advanced,3D MIMO (Three Dimensional MIMO) can be seen as a research focus in enhanced MIMO, for it can enhance the capacity and coverage of LTE-Advanced system. However, it is difficult to arranging a large number of antennas at both transmitter and receiver in an actual system. Moreover, planning of suitable resource allocation and proposing novel pre-coding algorithm are also big challenge in3D MIMO.The main work of this paper is the research of3D MIMO technique in LTE-Advanced system. Focusing on the inter-cell interference brought by LTE-Advanced frequency networking, we propose the3D MIMO technology and vertical dimension of antenna is introduced, so the performance of the overall system can be improved. Firstly, the architecture and key technologies of LTE-Advanced system architecture and key technologies are introduced in the beginning of this paper. Secondly, a3D channel modeling extended from2D channel is proposed based on WINNER channel characteristics. Thirdly, cell splitting and beamforming are proposed to enhance the system’s capacity and coverage. At last, numerical results of performance gain are obtained through simulation.There are two innovation points in this paper:First,3D cell splitting is achieved by utilizing the3D antenna elements in the vertical direction. A novel resource allocation scheme based on coordination telecommunication is proposed in this paper. In each scheduling period, resources of both inner sector and outer sector are assigned to specific sector edge users, which effectively improve the sector edge users’carrier to interference ratio (C/I). Second, Pre-coding algorithm is improved in3D MIMO transmission scheme. The improved pre-coding algorithm takes advantage of users’channel information of vertical dimension; the transmitting beam in the3D direction is aligned with the serving user. Thus,3D beamforming improves the throughput of the system significantly and enhances the performance of system’s coverage.System level simulation platform in this paper is set for LTE-Advanced. With different scenarios and different antenna parameters configuration, the performance results of3D MIMO have been proved. The results show that by using3D MIMO technology, both the cell average performance and the cell edge performance can be improved.