Study On 3D MIMO Precoding And User Scheduling Technology For 5G

With the increase in system bandwidth and data rates,the speed of mobile networks has also increased rapidly.Wireless mobile communications are in a period of rapid development,in the near future it will enter the era of 5G.3D MIMO technology,through the full use of space resources,make the base station can more effectively distinguish between different users and improve system performance,it has now become one of the key 5G mobile communication technologies.This paper first introduces the relevant theoretical knowledge of MIMO,and briefly analyzes MIMO transmission model.And focusing on three techniques: Single-user 3D MIMO precoding,Single-user 3D MIMO based on CSI-RS precoding and Multi-user scheduling algorithm design,the full text of the specific work is as follows:Firstly,four typical precoding schemes for Single-user 3D MIMO are studied,which are the point multiplication based precoding scheme,the equivalent channel based precoding scheme,the Kronecker Product based precoding scheme and the channel conversion based precoding scheme.Simulation and comparison of four kinds of precoding schemes are carried out under the URA antenna array model.The simulation shows that the system performance of the channel conversion based precoding scheme is better than that of the other three schemes.Second,Single-user precoding schemes based on CSI-RS are studied.Due to the significant increase in the number of transmit antennas,but the pilot resource overhead is limited,the available system gain will be hindered,which will put forward higher requirements for precoding scheme design,and in the existing methods,the transmitter often provides a data stream in the vertical direction,without effectively improving system performance.In order to solve the above problems,two precoding schemes based on CSI-RS are proposed.Thirdly,we study the Multi-user scheduling and Orthogonal codebook design,firstly,it is proved that the orthogonal establishment condition of Kronecker codebook under 3D MIMO system.In order to make full use of the orthogonality between codewords,an orthogonal codebook for Fourier perturbation of DFT matrices is proposed which has a strong inhibitory effect on the interference between different users under Multi-user system,and this paper proposes a corresponding user scheduling scheme.The simulation results show that the proposed Multi-user scheduling and orthogonal codebook design scheme can achieve higher system channel capacity.