Research On User Scheduling And Channel Tracking Algorithms In Massive MIMO

The fifth Generation Mobile Networks(5G)needs to support higher transmission rate than previous systems.Massive Multiple.Input Multiple.Output(massive MIMO)technology can greatly improve spectral efficiency,achieve higher capacity,and has the advantages of optimizing energy efficiency,which has attracted wide attention from industry and academia.The base station equipped with dozens or even hundreds of antennas,making the most of signal processing technology at this stage cannot be used directly.Traditional Linear Precoding and user scheduling schemes are facing enormous challenges.Thesis focuses on Linear Precoding and user scheduling schemes,and proposes channel tracking technology to reduce the negative effects of pilot pollution.The main research work is as follows:(1)Based on the matrix decomposition method of vector projection,an iterative algorithm of generalized minimum Residual Method(GMRES)is proposed to solve the RZF precoding scheme iteratively,and the corresponding complexity analysis and simulation are given.(2)A successive interference cancellation(SIC)receiver is adopted at the receiving terminal.Based on the existing precoding scheme,a scheduling strategy based on equal transmission signal power is designed.The corresponding scheduling algorithm is designed and the precoding matrix is modified.Finally,the simulation results show that the performance of the proposed scheduling scheme is better than that of Regularized Zero Forcing(RZF)precoding and JSDM scheduling strategy based on RZF precoding,however the system performance is poor when the number of users is small.(3)Based on channel tracking technology,this paper adopts the strategy of random scheduling to reduce the strategy of particle filter(PF)to deal with users,avoids the use of PF filter to predict all users,reduces the computational complexity and improves the system performance.The simulation results show that the channel tracking method can effectively improve the performance of the system in Imperfect Channel State Information(ICSI).