非正交多址系统中基于公平性改善的双层挤压迭代功率分配方法

Double layer squeeze iterative power allocation method based on fairnessimprovement in non-orthogonal multiple access systems

为了解决下行非正交多址系统中多用户通信的公平性问题,提出了基于公平性改善的双层挤压迭代功率分配方法。研究内容包括:首先,设计基于用户信道增益差的用户信道分裂过程,方便动态调整功率挤压时的挤压程度;其次,从强用户到弱用户进行内层功率挤压迭代,根据信道分裂情况设置挤压因子与附加挤压因子,使信道分裂处的弱用户对强用户挤压程度更强;第三,对内层挤压功率进行外层迭代的再分配与再挤压,可保持总功率不变的情况下,进一步提升功率分配的公平性。仿真结果表明:对比信道分裂下与信道未分裂下的公平性指数,其性能提升了25%;对比仅进行挤压因子与附加挤压因子调整,而未进行内外层迭代次数调整的情况,公平性指数性能提升了53.71%,同时,所提算法比注水算法达到的公平性指数明显改善,在公平性提升方面达到了较好的效果。

In order to improve the fairness of downlink non-orthogonal multiple access systems,this paper proposed a dual layer squeezing iterative power allocation method based on fairness improvement.Firstly,it designed a user channel splitting process based on user channel gain difference to facilitate dynamic adjustment of the degree of power squeezing.Secondly,it carried out the inner power squeezing iteration from strong users to weak users,and set the squeezing factor and additional squeezing factor according to the channel splitting situation,so that the weak users at the channel splitting point had a stronger squeezing degree towards the strong users.Thirdly,the reallocation and resqueeze of the inner power through outer iteration could further improve the fairness of power distribution,while maintaining the total power unchanged.The simulation results show that compared with the fairness index without channel splitting,it can improve the fairness with channel splitting by 25%;Compared to the situation that the squeezing factor and additional squeezing factor are only adjusted without the number of inner and outer iterations adjustment,it improves the fairness index performance by 53.71%.Meanwhile,the fairness of proposed algorithm is better than the waterfilling algorithm and gained a good fairness effect.