基于优先级的簇内终端直通数据转发策略

在蜂窝网络中,相同需求的用户可以建立成簇以利用终端直通(D2D)技术提高数据分发效率。然而,D2D链路质量的差异可能会成为提高资源效率的瓶颈。为了解决上述问题,在考虑链路质量差异的前提下,提出了基于优先级的D2D中继方案。该方案通过遍历链路质量矩阵自适应选取最优阈值,以优先选择可实现较高数据速率的D2D链路进行数据转发,提高了时频资源的利用率。与无优先级方案相比的仿真实验中：基于优先级的D2D中继方案消耗更少的时频资源,具有更高的资源效率,而且随着成功接收数据的用户（ACK用户）与未成功接收数据的用户（NACK用户）比值减小,优势更加明显;同时簇的大小对资源效率的改善也有一定影响。结果显示,对于簇内用户数目较少并且NACK用户多于ACK用户的情形,所提出的分级转发方案对资源效率的改善尤为明显。

Priority-based device-to-device data forwarding strategy in cluster

In cellular networks, users requesting the same data from base station can be grouped into a cluster, and Device-to-Device (D2D) links can be utilized to improve data dissemination efficiency. However, the difference of D2D links may be the bottleneck that results in conservative resource utilization. To solve this problem, a priority-based D2D relay scheme was proposed. The proposed scheme first set an optimal threshold by traversing the D2D links quality matrix, and then preferentially selected the D2D links with high achievable data rates to forward the data. In simulation experiment, compard with the traditional scheme without priority, the proposed scheme consumed less time and frequency resources with a higher efficiency especially when the ratio of ACK users and NACK users decreasing; meanwhile, the size of the cluster also influenced the improvement of resource efficiency. The results show that the proposed priority-based scheme improves resource efficiency when there is a small number of users, especially the users of NACK are more than that of ACK.