Research On Cooperative Transmission And Resource Allocation For Three-Dimension MIMO Systems

Wireless MIMO transmission is an important research direction in modern mobile communication sys-tem. With continuous development of antenna technology, the study of MIMO technology gradually develops from two dimensional(2D) space to three dimensional(3 D) space, from small and medium size MIMO to large-scale MIMO. Large-scale 3D MIMO transmission technology is capable of fully developing the additional vertical degrees of freedom and forming beams in the three dimensional space, resulting in a higher space division multiplexing gain. Faced with the development trend in the new generation of mobile communica-tion, this thesis researches efficient 3D MIMO transmission technology, with focus on the beam patterns of 3D MIMO transmission, limited feedback scheme and multiuser scheduling technology in FDD 3D MIMO system, and coordinated beamforming method for massive 3D MIMO heterogeneous networks. The main work and innovations of this thesis are as follows:Firstly, multiuser MIMO transmission scheme is investigated. We mainly discuss the multiuser limited feedback system based on codebook. We focus on analysising and comparing the performance of three kinds of limited feedback schemes, including normal feedback scheme (NFS), best companion pairing (BCP) and best companion cluster (BCC).Secondly, we study the characteristics of 3D MIMO channel and the beam patterns of 3D MIMO code-words, summarize 3D MIMO channel model and the corresponding antenna array model. Besides, the sta-tistical characteristics of 3D MIMO channel and 3D MIMO codewords are deeply researched. Simulations show that the autocorrelation function of 3D MIMO channel accords with bessel function of the first kind. According to the drawn beam patterns of studied 3D MIMO codewords, vertical codewords of the studied codebook control elevation and the horizontal ones control azimuth. As with the two dimensional channel, three dimensional channel also has the property of spatial sparsity.Thirdly, we focus on limited feedback based multiuser transmission scheme for 3D MIMO systems. We propose a new 3D MIMO codebook design method which is the Kronecker-product of horizontal and vertical codeword and further propose two kinds of vertical codebook design method. Then, we focus on the codebook based limited feedback scheme and reasonable multiuser scheduling policy. Simulations show that compared with traditional DFT codebook, the proposed vertical codebook makes full use of the space vertical dimension, reasonably divides the vertical dimension of the space, efficiently matches the three dimensional channel, thus significantly improves the spectral efficiency and throughput of the 3D MIMO system.Finally, coordinated beamforming method for massive MIMO heterogeneous networks is investigated. We propose a coordinated beamforming method, which efficiently suppresses the severe interference from the macro base station (MBS) to the lower-power cell users by dynamically closing corresponding beams. We propose a two-stage coordinated beamforming scheme at MBS to suppress the severe cross-layer interference in heterogeneous network through the exchange of statistical channel information between macro cell and lower-power cells. Furthermore, we extend our approach to the case of three dimensional (3D) beamforming. Simulations show that our proposal is particularly effective when the number of antennas at the MBS is sufficiently large.