Research On Power Allocation Algorithms In Millimeter Wave Massive MIMO-NOMA System

The combination of Millimeter Wave(mm Wave)and Massive Multiple-input and Multiple-output(Massive MIMO)technology is considered to be the key technology in 5G communication.mm Wave communication solves the problem of spectrum resource shortage,but mm Wave communication has a high path loss in the high frequency band,and the beamforming gain of massive MIMO technology can make up for this path loss,and the shorter wavelength of mm Wave communication It is also beneficial for antenna deployment in Massive MIMO.The use of a hybrid precoding scheme in a mm Wave Massive MIMO system can effectively reduce the number of RF links,the system energy consumption and system performance will not suffer a great loss.The reduction in the number of RF links means that the number of users that can be served in the system is reduced.Therefore,non-orthogonal multiple access(Non-Orthogonal Multiple Access,NOMA)technology is introduced to increase the number of users that the system can service.In this thesis,the power allocation algorithm of mm Wave Massive MIMO-NOMA system under hybrid precoding scheme is studied.The main research contents of this thesis are as follows:This thesis first introduces basic theories of optimization problems,including basic concept of optimization problems,Lagrange dual function,KKT equation and two classical convex optimization problems.The basic principle of NOMA technology is studied,the classical downlink NOMA system model is introduced,the system capacity of NOMA and OMA is compared,and the superiority of NOMA is proved.The basic principles of MIMO and the MIMO-NOMA system model are introduced.Finally,The mm Wave transmission characteristics and channel model are studied.Then,in this thesis,the channel capacity of single-user Massive MIMO and multi-user Massive MIMO systems are introduced,the digital precoding architectures is introduced,and the advantages and disadvantages of three classic digital precoding are studied,the analog precoding is proposed.finally,the Millimeter-wave massive MIMO system model is introduced,the two antenna array structures and the definitions of the system energy efficiency in the mm Wave Massive MIMO system are introduced.and under this system,spectrum efficiency and energy efficiency are used as thr performance evaluation indicator.Through the simulation,the hybrid precoding scheme is the best precoding scheme in the mm Wave Massive MIMO system is proved.Finally,in this thesis,two power allocation algorithms for mm Wave Massive MIMONOMA systems are introduced.Both power allocation algorithms are designed to maximize the system's energy efficiency under the restriction of user service quality requirements and power constraints per cluster.then the problems that exist in the two power allocation algorithm is improved in the improved power allocation algorithm.Finally,the energy efficiency performance of the improved power allocation algorithm and the original power allocation algorithm is analyzed through simulation,and the algorithm complexity between the two algorithms is compared.