Hybrid Beamforming Technology Of Millimeter Wave MIMO Wireless Communication System

With the rapid growth in demand for mobile data,low-band communication has been unable to meet the rapid growth of data traffic demand.High-frequency band has been concerned and researched by the industry experts and scholars.Millimeter wave frequency band is in the 30GHz-300 GHz.Due to its large number of band resources,millimeter wave frequency is the key band to achieve 10Gbps throughput of indoor WLAN and the fifth generation of mobile communications.In order to further improve system throughput and support multiple data streams,millimeter wave communications will combine multiple-input multiple-output with hybrid beamforming techniques.Therefore,hybrid beamforming technology is studied in this paper,and the main contents related to this study are organized as follows:Firstly,the hybrid beamforming technology is described in detail.According to the characteristics of millimeter wave channel propagation,the characteristics of free space loss,rainfall attenuation and osmotic loss are analyzed emphatically.Further,the 45GHz channel model is introduced in detail.Finally,the definition,architecture model and solution method of hybrid beamforming technology is described,which lays the foundation for the research of the following chapters.Secondly,two schemes for solving the antenna weight vector of the split sub-arrays are proposed.The first solution is to use the codebook to determine the antenna weight vector of the antenna sub-arrays based on the idea of elimination of the sub-arrays interference,and the second solution is to determine the antenna weight vector of the antenna sub-arrays by two stages optimization.The simulation results show that the performance of the proposed two solutions is superior to the existing literature schemes,and can effectively reduce the system complexity.Thirdly,an algorithm for solving the analog beamforming based on signal to interference plus noise ratio maximization is proposed,and a single user millimeter wave MIMO hybrid beamforming scheme is designed.According to the proposed algorithm,the antenna weight vector of the sub-arrays is optimized in two directions,and then the analog beamforming is determined and the digital beamforming is further solved.The simulation results show that the proposed algorithm has high convergence speed and low computational complexity,and the single user millimeter wave MIMO hybrid beamforming scheme based on this algorithm can achieve a good trade-off between performance and complexity.Finally,a multi-user fair scheduling algorithm based on beam half orthogonal is proposed.Aiming at the millimeter wave multi-user MMO hybrid beamforming system,a multi-user asymmetric hybrid beamforming scheme is proposed,which proposes a scheduling algorithm which can take into account the diversity gain of users and the fairness between users.The simulation results show that the proposed fair scheduling algorithm can realize the fairness between users without obvious loss of performance.