Research And Design Of 3D MIMO Channel Estiamtion For 5G

3D MIMO technology can simultaneously utilizing the angle information of the horizontal and vertical dimension of the antenna array,which greatly improves the system capacity and is one of the key technologies of 5G.Today's spectrum resources for communication are very limited,millimeter wave is an electromagnetic wave with a frequency between 30 GHz and 300 GHz.The millimeter wave technology can solve the problem of today's spectrum scarcity.The combination of millimeter wave technology and 3D MIMO technology is the trend of future development of mobile communication technology.As a physical structure,lens is an antenna array technology that scholars have found can be applied to base station in recent years.It can solve the problem of complex structure and high cost of antennas,and can convert space channel into beamspace.The beam spatial channel is sparse,so how to use the sparseness of the beam space channel for channel estimation is the focus of this article.The main work of this article is as follows:First of all,the characteristics of the wireless communication channel and the difference between the 2D MIMO system and the 3D MIMO system are studied.The free space loss in wireless communication channels and fading types of wireless communication channels are analyzed.The advantages of 3D MIMO technology in 5G communication are introduced and the applicable scenarios are given.Secondly,the channel estimation method in large-scale millimeter-wave 3D MIMO systems based on lenses is studied.The role of the lens antenna technology and the sparse characteristics of the beam space channel are analyzed in detail,and then the channel estimation is performed by using its sparse characteristics,a low complexity cross-channel estimation scheme is proposed.Simulation results show,the computational complexity of the proposed algorithm is half that of the dual-cross channel estimation method and does not lose estimation accuracy.Thirdly,the channel estimation method for large-scale millimeter-wave 3D MIMO with spatial wideband effect is studied.The spatial wideband effect in large-scale MIMO and the channel model of massive MIMO with spatial wideband effect are analyzed in detail,and then extended it to large-scale millimeter-wave 3D MIMO systems,the sparse characteristics of the channel in the angular delay domain are analyzed,a channel estimation method based on angular delay domain sparse property is proposed.Simulation results show,the proposed algorithm has good channel estimation performance.