基于树形搜索的NOMA系统功率分配算法  

Tree-based search algorithm for power assignment in non-orthogonal multiple access systems

作　　者：高翔[1] 谭歆[1] 吴广富[1] 肖杰[1] GAO Xiang;TAN Xin;WU Guangfu;XIAO Jie(Chongqing Key Lab of Mobile Communication Technology,Chongqing University of Posts and Telecommunications, Chongqing 400065,P.R. China)

机构地区：[1]重庆邮电大学移动通信技术重庆市重点实验室,重庆400065

出　　处：《重庆邮电大学学报（自然科学版）》2017年第5期665-671,共7页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：国家高技术研究发展计划资助("863"计划)(2015AA01A709);长江学者和创新团队发展计划资助(IRT1299);重庆市重点实验室专项基金(CSTC);重庆市教委科学技术研究项目(KJ1500406;KJ1500408)~~

摘　　要：功率分配是影响非正交多址接入(non-orthogonal multiple access,NOMA)系统性能的一个重要因素。传统树形搜索功率分配算法在吞吐量方面虽然能达到全搜索算法的性能,但该算法具有较高的计算复杂度,而固定功率分配算法和分数阶功率分配算法虽然计算复杂度低,但不能达到较好的吞吐量性能。为了解决这个问题,提出了一种基于树形搜索的递增功率分配算法。该算法以最大化用户吞吐量的几何平均作为目标函数,采用功率递增的分配方式,将用户分配到树形模型中,并对用户逐层搜索筛选,根据给定的功率系数标准和吞吐量标准,舍去多余节点,保留幸存节点,直到完成所有用户的功率分配。仿真结果表明,该算法的吞吐量性能与全搜索算法相比,在没有明显下降的情况下,较大地降低了计算复杂度。Power assignment plays a key role in the performance of non orthogonal multiple access(NOMA).The existing tree search power allocation algorithms can achieve the performance of exhaustive search algorithm in throughput performance,while causing the high computational complexity extremely.In contrast,fixed power allocation algorithm and fractional power allocation algorithm have low computational complexity.However,the throughput performance are not satisfied.To this end,a tree based search algorithm for incremental power assignment is proposed for trade off.The proposed algorithm sets the maximizing geometric mean user throughput as the objective function,and it uses the manner of incremental power assignment to assign users to the tree model,and keeps survived node for filtering layer by layer in accordance with the given power metric and throughput metric to discard redundant nodes.Compared with exhaustive search algorithm,the proposed algorithm greatly reduces the computational complexity without significant throughput decline.

关 键 词：非正交多址接入 功率分配 几何平均 树形搜索 

分 类 号：TN929.5[电子电信—通信与信息系统]