Non-orthogonal multiple access (NOMA) based wireless caching network (WCN) is considered as a promising technology for next-generation wireless communications since it can significantly improve the spectral efficiency. In this letter, we propose a quality of service (QoS)-oriented dynamic power allocation strategy for NOMA-WCN. In content placement phase, base station (BS) sends multiple files to helpers by allocating different powers according to the different QoS targets of files, for ensuring that all helpers can successfully decode the two most popular files. In content delivery phase, helpers serve two users at the same time by allocating the minimum power to far user according to the QoS requirement, and then all the remaining power is allocated to near user. Hence, our proposed method is able to increase the hit probability and drop the outage probability compared with conventional methods. Simulation results confirm that the proposed power allocation method can significantly improve the caching hit probability and reduce the user outage probability.

中文翻译：

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基于 NOMA 的无线缓存网络中面向 QoS 的动态功率分配

基于非正交多址（NOMA）的无线缓存网络（WCN）被认为是下一代无线通信的有前途的技术，因为它可以显着提高频谱效率。在这封信中，我们为 NOMA-WCN 提出了一种面向服务质量 (QoS) 的动态功率分配策略。在内容放置阶段，基站(BS)根据文件的不同QoS目标分配不同的功率，将多个文件发送给Helper，以确保所有Helper都能成功解码两个最流行的文件。在内容交付阶段，Helper根据QoS要求将最小的功率分配给远端用户，同时为两个用户提供服务，然后将剩余的功率全部分配给近端用户。因此，与传统方法相比，我们提出的方法能够增加命中概率并降低中断概率。仿真结果证实，所提出的功率分配方法可以显着提高缓存命中概率，降低用户中断概率。