多载波NOMA系统总和速率最大化研究

Research on Maximum Sum Rate of Multi-carrier NOMA System

随着移动通信的迅猛发展,社会各界的关注点转移到非正交多址接入(non-orthogonal multiple access,NOMA)技术。在保证用户公平性的前提下如何最大化NOMA系统的总和速率,社会各界对多载波NOMA系统的资源分配算法进行了研究,包括用户分组和功率分配算法。为解决此类复杂的非线性问题,采用了分步优化的策略,先对用户进行分组,将分组完成的用户复用到子载波上,提出一种稳定匹配分组算法,根据等效信道增益选择初步的分组方案,再根据系统总和速率的大小确定最终分组。再对用户组进行功率分配,采用了一种基于遗传算法的功率分配算法,通过若干次迭代,进化得到该条件下的最优功率分配方式。仿真结果表明,提出的用户分组和功率分配算法在计算复杂度较低的前提下有效地提高了NOMA系统的总和速率。

With the rapid development of mobile communications,the attention of all sectors of society has shifted to non-orthogonal multiple access(NOMA)technology.In order to maximize the sum rate of the NOMA system on the premise of ensuring user fairness,the community has studied the resource allocation algorithm of the multi-carrier NOMA system,including user grouping and power allocation algorithms.In order to solve such complex nonlinear problems,a step-by-step optimization strategy is adopted.The users are grouped firstly,and the grouped users are multiplexed onto a sub-carrier.A stable matching grouping algorithm is proposed to select the preliminary grouping scheme according to the equivalent channel gain,and then determine the final grouping according to the sum rate.Then power allocation is performed on users,and a power allocation algorithm based on genetic algorithm is adopted.Through several iterations and evolutions,the optimal power allocation method under this condition is obtained.The simulation shows that the proposed user grouping and power allocation algorithm can effectively increase the sum rate of the NOMA system under the premise of low computational complexity.