Research On Large-scale MIMO Millimeter Wave Hybrid Precoding

With the increasing demand for mobile Internet,more challenging requirements are put forward for the fifth generation mobile communication system(5G),such as high-frequency spectral efficiency,high energy efficiency and a large number of connections.In order to meet aforementioned challenges,Numerous scholars have designed and studied large-scale millimeter wave(mm Wave)multiple input multiple output(MIMO)systems in recent years.In large-scale MIMO communication scenarios,using the all-digital precoding scheme can improve the communication performance,but it is accompanied by huge energy consumption.In order to improve the energy efficiency of the system,the all-digital channel precoding matrix can be decomposed into a low-dimensional digital matrix and a high-dimensional analog matrix,that is,a hybrid precoding matrix.Hybrid precoding of channels can save energy while improving the performance of communication systems.The iterative optimization hybrid precoding scheme of non-orthogonal multiple access(NOMA)can further improve the energy efficiency and spectrum efficiency of the system.Therefore,it is significant to study the communication scheme of non-orthogonal multiple access in large-scale millimeter wave.The major contents of this paper are as below:(1)In an effort to improve the performance of large scale millimeter wave MIMO,a hybrid precoding algorithm based on target decomposition is proposed.This algorithm is based on objective decomposition,and studies the design of hybrid precoding matrix by using successive iterative approximation,alternate optimization and model design method of adding relay equipment to expand the transmission range.The simulation results display that compared to other existing algorithms,the proposed hybrid precoding algorithm can achieve more ideal system mean square error and sum rate,and its performance is close to the ideal precoding performance.It can be seen that the algorithm has very good effectiveness and reliability.(2)In order to achieve high spectral efficiency and high energy efficiency in large scale millimeter wave MIMO systems,a NOMA iterative optimization hybrid precoding scheme is proposed.This scheme is based on the partial connection architecture model,and uses NOMA mode,wireless portable communication type,iterative optimization algorithm and cluster head selection algorithm to research the precoding issues.The simulation results indicate that compared to else existing hybrid precoding algorithms of orthogonal multiple access(OMA)for wireless portable communication,the spectral efficiency and energy efficiency of the proposed algorithm approach the ideal value.In summary,this paper improves the spectrum efficiency and energy efficiency of the communication systems through the design of the channel precoding matrix,which better meets the growing demand in the context of big data.