针对TDD系统中多个D2D用户复用一个蜂窝用户下行信道资源,在最大化系统吞吐量的目标下,提出一种D2D对分组资源分配算法,该算法由3部分组成:1)根据信道数确定D2D对分组数,按D2D对间距确定分组中心,并将余下D2D对按其对组内D2D用户通信中断概率影响程度划分到对应分组;2)通过比较D2D对分组与蜂窝用户干扰影响强度,利用匹配算法为D2D对分组寻找相应蜂窝用户资源并复用;3)进一步根据蜂窝用户和D2D用户QOS要求,去掉组内干扰较大D2D对,从而得到最终复用蜂窝用户资源的D2D对.仿真分析表明:所提出算法既能允许系统接入较多D2D对,还能提高系统吞吐量.
Due to multiple D2D users and one cellular user sharing the same downlink channel resources in TDD systems,an algorithm of resource allocation based on grouping for D2D pairs is proposed to maximize the system throughput, which consists of three parts. This algorithm firstly determines the D2D groups number with the system channels number and the user grouping position centre in terms of the distance among the D2D pairs,and divides the remaining D2D pairs into corresponding groups according to its degree of effect on the communication outage probability of users within the same D2D group. Afterwards,by comparing the interference impact of D2D group on the cellular user, the matching algorithm is used to determine and share the corresponding cellular channel resource for D2D group. Finally, according to the different QOS of cellular users and D2D pairs,the D2D pairs with serious interference are deleted and the D2D pairs sharing the cellular channel resource are finally determined. Simulation results show that more D2D pairs can access to the system and the system throughput is improved by the proposed algorithm.