The Research Of 3D-MIMO Beamforming Technology In Future 5G System

Spectral efficiency has always played an important role in the research,development and deployment of mobile communications.In this internet age with data explosion,lots of terminals emerge,the demand for system spectrum efficiency will be more urgent.In the early 1990 s,the discovery of multi-antenna spatial multiplexing technology makes it possible to increase spectrum efficiency under limited bandwidth.To further tap the potential of space-division multiplexing,due to the number of deployed antennas is positively related to spatial freedom,in 2010 Marzette of Bell Labs proposed the massive MIMO system and verified the advantages of system.Based on the fact that the electromagnetic wave propagating in three dimensional space,the 3D-MIMO system is known as the core technology of 5G.Firstly,this thesis gives a thorough survey on 3D-MIMO beamforming and summarizes three kinds of 3D-MIMO beamforming methods,as the correlation-matrix based3 D beamforming,codebook based 3D beamforming and ZF based 3D beaforming techniques.And the analysis and the simulation results of these schemes are also presented.The performance of 3D-MIMO while considering the influence of different reference signal configuration is also analyzed in the thesis.Secondly,this thesis proposes a novel 3D-MIMO beamforming method,which can completely eliminate interference at one dimension and maximize performance at another dimension.Comparing with the conventional 3D-MIMO schemes,the proposed method can achieves a better performance gain with lower computational complexity.At last,the work of high order modulation in massive MIMO system with LTE link level platform is given.It is verified that massive MIMO combined with high order modulation such as 1024-QAM is able to improve the system throughput significantly.In order to further increase the throughput of the system,the link adaptation technique is also implemented in the platform to adjust the modulation order according to the channel state information to maximize the system capacity.