To increase the feasibility of wireless powered communication networks (WPCNs), the synergy of efficient multiple access protocols and diverse types of resources, e.g., multiple antennas, memories, and energy storage devices is of paramount importance. To this end, in this paper, we introduce the use of buffered sources in WPCNs with uplink non-orthogonal multiple access, in which a multi-antenna hybrid access point can both transmit energy and receive information. The proposed scheme aims at maximizing the long-term utility function, which is determined by the achieved average data rate and fairness among sources. The formulated long-term time-average optimization problem is converted into instantaneous ones by exploiting the Lyapunov optimization framework. The derived analytical solutions reveal the impact of data buffers’ length on the decoding order of sources’ messages. Finally, it is shown that the proposed scheme achieves superior long-term utility compared to the considered baseline schemes with non-buffered sources and buffered sources with orthogonal multiple access. Additionally, it is demonstrated that our proposed scheme can ensure fairness without reducing the average data rate.

中文翻译：

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NOMA 用于具有缓冲源的无线供电通信网络


为了提高无线供电通信网络（WPCN）的可行性，高效的多址接入协议和多种类型的资源（例如多个天线、存储器和能量存储设备）的协同作用至关重要。为此，在本文中，我们介绍了在上行非正交多址接入的 WPCN 中使用缓冲源，其中多天线混合接入点既可以传输能量又可以接收信息。所提出的方案旨在最大化长期效用函数，该函数由所实现的平均数据速率和源之间的公平性决定。通过利用 Lyapunov 优化框架，将公式化的长期时间平均优化问题转换为瞬时问题。导出的分析解揭示了数据缓冲区长度对源消息的解码顺序的影响。最后，结果表明，与考虑的具有非缓冲源和具有正交多址的缓冲源的基线方案相比，所提出的方案实现了优越的长期效用。此外，事实证明我们提出的方案可以在不降低平均数据速率的情况下确保公平性。