Beamforming Techniques Analysis In3D MIMO Systems

3D multiple input multiple output (MIMO) has become a hot spot in standardization study. While beamforming technique is core part of3D MIMO techniques, it has attracted more and more interesting with its dy-namic downtilt adjustment, improved system capacity and interference elimination. In this paper, we study different problem that the complexity of traditional beamforming algorithm is high in3D MIMO systems and traditional algorithm can not fit the3D channel characteristic well. The work can be categorized as three parts:First, evaluation of different beamforming algorithm. In3D MIMO systems, antenna array has changed. In the new channel environment, we want to know which beamforming algorithm can perform well in3D MIMO systems. In this paper, we evaluate different algorithm including both codebook based and not codebook based beamforming algorithm.Second, we research regularized block diagonalization (RBD) algo-rithm in3D MIMO systems. Undertake research results of the first part, we will do further study of BD algorithm which has good performance in MU MIMO systems. RBD algorithm is a minimum mean square error method based method with users have not only one antenna. RBD benefit well than BD in throughput. Due to the significant number of antennas at the base station, the complexity of RBD increase significantly. But when the dimension of the channel matrix is big, the structure of beamforming matrix is special. For this discovery, we present a new algorithm. Simula-tion and theoretical analysis show that the algorithm can reduce the com-plexity of the algorithm RBD, but not reduce the throughput performance.Third, investigation of discrete fourier transform (DFT) based3D beamforming algorithm. DFT algorithm which is direction of arrival (DOA) based is adopt as one of MIMO algorithm for its’simplicity. But in3D MIMO systems, the regular DFT algorithm can not adjust the an-tenna array well. Motivated by this observation, a3D DFT algorithm was proposed. Through the simulation, we find the proposed algorithm has better performance than the former DFT algorithm.These are the main content of the work and innovation of this article. I wish these results may provide reference and basis in the following for those who study of3D beamforming.