Analysis Of Precoding For Massive MIMO Systems

Multiple input multiple output(MIMO)has been widely used for its improvement of the capacity of wireless communication system.With the increasing demand for wireless communication of users and the innovation of related communication technology,the research of MIMO has become one of the hottest topics in the study of communication theory.In the past several years,the research of fifth generation(5G)mobile communication is put forward,and massive multiple input multiple output(massive MIMO)has been regarded as a key point of it.Massive MIMO uses hundreds of antennas at the base station to support large numbers of users.The large scale antenna arrays ensure the broadcast channel of communication,and provide high spectrum efficiency with lower original requirements and less air interface delay,etc.Therefore,massive MIMO becomes a core technology in the next generation mobile communication system.In downlink MIMO system,users will not only receive the data they need,but also get interference from other users,especially in the case of massive MIMO system.The large number of antennas will bring strong effect from the interference.Often,the users can't share the information for the limits of power and antenna number.In this case,for MIMO system,precoding techniques are used to suppress the interference.This paper will premise it and deeply discuss the precoding processing schemes in massive MIMO system.Firstly,this paper introduces the correlation knowledge of wireless channel fading.It points out the influence factors of channel fading and classifies them.And several basic models of MIMO system are discussed,including single user multiple input multiple output(SU-MIMO)system and multiple users multiple input multiple output(MU-MIMO)system.Then in this paper,some relevant simulation analyses are expressed.Meanwhile,this paper introduces some precoding methods based on the traditional MIMO system,according to the classification standard of linear and non-linear processing,typical precoding schemes are analyzed and simulated.Afterwards,in view of the module algebra precoding,this paper take the number theory of lattice reduction(LR)with precoding schedule and proposes two improved precoding schemes.The simulation results show that these two schedules are better than the traditional precoding scheme in performance,especially in the high signal noise ratio(SNR)environment.Then,this paper explores the massive MIMO system and its basic properties,and uses the two kinds of schemes above to analysis.The result shows that,the use of lattice reduce with the precoding can not only improve the system performance,but also reduce the cost of calculation.Finally,the research achievements of full text are summarized,and the next possible solutions are proposed.