Research On Optimization Of User Grouping And Power Allocation In Non-orthogonal Multiple Access System

With the continuous development of the mobile Internet,mobile data presents the fast growth the tendency,new applications appear constantly.The Fifth Generation will face huge requirements of connectivity and faster transmission rates of data traffic.So proposing a new multiple access technology to solve the problems,which achieve to succeed in improving data rate,the abatement of transmission delay,the plausible allocation of energy,the saving of the prime costs,to add the massive equipment connections,and Can markedly increase the system capacity.In the next generation cellular communication,non-orthogonal multiple access(NOMA)technology has great potential.Traditional multiple access technology is studied in time domain and frequency domain.In NOMA technology,the research of power domain is added,and the power domain multiplexing technology is introduced in the transmitter,so that multiple users can share resources and get rid of the limitation of traditional single user exclusive resources.In this thesis,the optimization of user grouping and functional power allocation in NOMA downlink system is studied.Firstly,this thesis expounds the principle of non-orthogonal multiple access system,and analyzes the advantages of non-orthogonal multiple access system in energy saving and consumption reduction.Based on the following Noma system model of line link,several user grouping algorithms and power allocation algorithms at the base station sender are introduced,and the basic principle of interference elimination algorithm at the receiver is analyzed.Secondly,I studied the multi-user grouping and power distribution scheme of transmitting end in NOMA system.Due to the poor performance of the existing exhaustive algorithm for user grouping and power distribution system,this thesis proposes to use the Kuhu-Munkres algorithm to group users for this problem,and after the users are grouped,based on the results of this user grouping strategy,A joint power allocation scheme is proposed.Finally,aiming at the power distribution of non-orthogonal multiple access system,this thesis proposes a power allocation scheme to optimize the energy efficiency of the system.In this scheme,the total learning particle swarm optimization algorithm is used to allocate power,and the performance index is the energy efficiency of the system.Firstly,an optimization model is established to meet the user's requirement of minimum speed,and then the power allocation factor is obtained by using comprehensive learning particle swarm optimization algorithm.The energy efficiency of the system is optimized under the premise of ensuring the spectrum efficiency of users.