Research On Precoding Technology In Millimeter Wave MIMO Systems

In the research of the fifth generation of wireless communication technology,millimeter wave(mmWave)communication has gained extensive attention and research by virtue of its advantages such as wide spectrum,anti-interference ability and easy integration.The combination of mmWave technology and the large-scale MIMO system,which has been widely used at present,can greatly improve the available bandwidth and spectrum efficiency,which is a promising technology for future 5G wireless communication systems.At the same time,the mm Wave signal undergoes a significant path loss over the microwave signals currently used in most wireless applications and all cellular systems.The application of large antenna arrays can alleviate the problem of path loss in millimeterwave systems.Beamforming(ie,precoding)of multiple data streams can further improve the spectral efficiency of mmWave.In a conventional multi-antenna system,precoding is performed digitally on the baseband.However,the high cost and high power consumption of mixed-signal hardware in mmWave systems forces mm Wave to rely more heavily on analog processing.Based on the whole antenna array,a new antenna array which was used to replace the whole antenna array structure and the precoding of the whole system is completed in the digital domain and the analog domain.An improved hybrid precoding algorithm based on orthogonal matching pursuit is proposed.By decomposing the complex channel capacity problem into several independent subproblems,and using the idea of continuous interference cancellation to solve the interference between sub-antenna arrays,the maximum channel capacity of the whole system can be obtained.The simulation results show that the proposed hybrid precoding algorithm is very close to the optimal algorithm in performance,and the complexity is greatly reduced.