The Researchment Of Precoding Technology In 3D MIMO System

To counter the adverse effects in various wireless communication environments and surpressing various interferences, the precoding technology is one of the key technologies in 5G. The traditional 2D MIMO communication system only considers the azimuth angle in the signal transmission, ignoring the elevation angle. As a result, it can’t make full use of space freedom. In 5G, we should make full use of the elevation dimension of freedom in 3D channel, and dig out potential of the MIMO technology in the improvement of the overall efficiency of the mobile communication system and user experience.This thesis is to research 3D MIMO precoding. Based on the main scene in the LTE / LTE-Advanced, we study single user 3D MIMO precoding technique, single user 3D MIMO improved precoding technology based on the correlation matrix and multiuser 3D MIMO precoding technology. The main contents of this paper are as follows:Firstly, this paper researches the single user 3D MIMO precoding technology. We analyze 3D MIMO antenna array as well as the respective channel impulse response and propose two 3D MIMO precoding system designs and make simulation analysis.Secondly, we research single user 3D MIMO improved precoding technology. We analyze the elevation and azimuth correlation matrix of the general antenna array and deduce the correlation matrix expressions in azimuth and elevation dimension for cylindrical and rectangular array. Finally, we propose the improved precoding technology based on the correlation matrix and make simulations.Thirdly, we first research the multi-use MIMO system model, and then specifically analyze the block diagonalization precoding, MMSE precoding and maximum signal to leakage and noise ratio precoding technology. Finally, on this basis, the above precoding algorithms are applied to the 3D MIMO system and make simulations.