Research On Hybrid Precoding In MmWave Massive MIMO Wireless Communication System

Millimeter-wave massive MIMO technology is considered to be the key technology for 5G networks,which can cope with the explosive growth of mobile data.Different from traditional MIMO,the large number of antennas and radio frequency chains in millimeterwave massive MIMO systems make it difficult to apply traditional digital precoding techniques.Hybrid precoding is an alternative to solving this problem.Considering the implementation cost and power consumption,the design of the hybrid precoding algorithm needs to be considered comprehensively between performance and design complexity.Based on the existing research on millimeter wave massive MIMO hybrid precoding,this thesis aims at maximizing spectrum efficiency and further optimizes spectrum efficiency and complexity.The main research contents of this paper are as follows:1.In order to further optimize the spectral efficiency and algorithm complexity of the joint design hybrid precoding for millimeter wave multiple input multiple output system in transceiver,a low-complexity joint design of the hybrid precoding scheme is proposed,First,H(?)lder inequality is introduced to formulate analog precoding and analog combiner,and then use the alternating minimization principle to improve the spectrum efficiency;second,the singular value decomposition is performed to solve the digital precoding matrix and the digital combination matrix;finally the initial value of the algorithm is optimized to further improve the algorithm's spectral efficiency and reduce complexity.Simulations verify that the proposed scheme has better spectrum efficiency and lower complexity than other hybrid precoding schemes.2.In order to better realize the vision of 5G,in a MIMO system,a hybrid connection antenna structure can combine the advantages of a fully connected structure and a partially connected structure to better balance the relationship between spectral efficiency and energy efficiency.However,the hybrid precoding algorithm of this structure is complicated.To solve this problem,the design of low-complexity hybrid precoding algorithm for hybrid connection structure is studied.In order to simplify the hybrid precoding algorithm of the hybrid connection structure,the channel matrix is divided into a series of sub-channel matrices,and then the alternate iterative matrix decomposition(Alt-IMD)algorithm is used to solve the optimal mixture Precoding matrix.The algorithm complexity is analyzed theoretically,and the spectral efficiency and energy efficiency of the fully connected antenna structure,the partially connected antenna structure hybrid precoding algorithm and the hybrid precoding algorithm here are compared through simulation experiments.The results illustrate that: in proportion to the current hybrid precoding algorithms,the hybrid precoding algorithm proposed here can achieve higher spectral efficiency and energy efficiency.