MIMO系统中基于非正交多址接入的功率分配算法研究

随着移动通信技术的发展,通信服务已变成人类日常生活中不可或缺的部分.尤其是近年来各类智能终端的大众化,使得接入无线通信的用户数和人们对通信服务的需求均呈爆炸式的增长.但现如今可用的频谱资源是有限的,且传统的正交多址接入系统的用户接入数受限,很难满足用户日益增长的需求.非正交多址接入允许在同一时频资源上复用多个用户,极大...

Study on Power Allocation Algorithm Based on Non-Orthogonal Multiple Access in MIMO Systems

With the development of mobile communication technology,communication services have become an indispensable part of human’s daily life.As one of the basic technologies of wireless communication,multiple access technology is a necessary means to satisfy the simultaneous communication of multiple users in wireless network,and each generation of mobile communication has a specific multiple access technology.For example,the iconic multiple access technology in the first generation of mobile communications is frequency division multiple access technology,while it is orthogonal frequency division multiple access in fourth generation mobile communication.In recent years,the popularity of various types of intelligent terminals,such as smart phones,laptops,smart glasses and smart watches,has led to an explosive growth in the number of users allowed to access wireless communications,and people’s demand for communication services has also increased dramatically.However,the available spectrum is limited,and only one user are allowed in each subchannel in traditional orthogonal multiple access systems,such as orthogonal frequency division multiplexing systems,which limits the number of users allowed to access.Therefore,it is difficult for orthogonal multiple access systems to meet the increasing needs of users.Non-orthogonal multiple access allows multiple users to be multiplexed on the same time or frequency resource.Compared with orthogonal frequency division multiple access systems,the number of users allowed by the system and the spectral efficiency is greatly improved.The application of non-orthogonal multiple-access technology to a multiple-input multiple-output system further can improve the performance of some aspects of the system.Aiming at the problem of high complexity of power allocation algorithms in the existing researches in multiple-input multiple-output non-orthogonal multiple-access systems,considering the imperfect serial interference cancellation,a low complexity power allocation algorithm based on Stackelberg game is proposed.Stackelberg game is a game model in economics,which studies the economic behavior competition between leaders and followers.In Stackelberg game model,the party that makes the decision first is called the leader.The remaining players make decisions based on the leader’s decision,and are called followers.To reach the Nash equilibrium,both the leader and the follower of the game choose their own strategies based on the other’s possible strategies to ensure that their interests are maximized.Firstly,a Stackelberg game is employed in which the base station is modeled as a seller(leader)and users in the cell are modeled as buyers(followers).Then,the Largrange function is used to find the optimal power under constraints,which is a function of price.Finally,the optimal price set by the station for each user is obtained.In the process of game between the base station and users,the price is dynamically adjusted by the base station to maximize its own revenue.Simulation results show that,compared with the fractional transmit power allocation,the proposed algorithm achieves 15.65%increase in throughput when the system power is 24 dBm and the serial interference cancellation residual factor is 0.001.Besides,the computational complexity and power consumption are reduced on the basis of performance similar to the algorithm proposed in10].