This paper studies the performance of multi-hop cognitive wireless powered device-to-device (D2D) communications in wireless sensor networks (WSNs). In our analysis, each sensor node harvests energy from multiple dedicated power beacons and shares the spectrum resources with multiple primary receivers (PRs) using underlay cognitive radio. Additionally, we consider a practical scenario of cognitive wireless powered D2D communications in WSNs, where the knowledge of interference channels is assumed to be imperfect. To improve the network performance, we propose two user scheduling schemes, namely dual-hop scheduling (DHS) and best-path scheduling (BPS) schemes. We then investigate the performance of the proposed scheduling schemes in terms of outage probability and outage floor. Through numerical results, we show that BPS scheme significantly outperforms DHS scheme, which in turns outperforms the state-of-the-art solution. Moreover, the advantages and drawbacks of each scheme are analyzed and discussed comprehensively. We also point out that the inaccurate knowledge of the interference channels significantly affects any performance metric of multi-hop cognitive D2D communications in WSNs such as outage probability, outage floor, and performance loss.

中文翻译：

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关于 WSN 中多跳认知无线 D2D 通信的性能

本文研究了无线传感器网络 (WSN) 中多跳认知无线供电的设备到设备 (D2D) 通信的性能。在我们的分析中，每个传感器节点从多个专用功率信标收集能量，并使用底层认知无线电与多个主要接收器 (PR) 共享频谱资源。此外，我们考虑了 WSN 中认知无线 D2D 通信的实际场景，其中假设干扰信道的知识是不完善的。为了提高网络性能，我们提出了两种用户调度方案，即双跳调度（DHS）和最佳路径调度（BPS）方案。然后，我们在中断概率和中断底限方面研究了所提出的调度方案的性能。通过数值结果，我们表明 BPS 方案明显优于 DHS 方案，后者又优于最先进的解决方案。此外，对每种方案的优缺点进行了全面的分析和讨论。我们还指出，干扰信道的不准确知识会显着影响 WSN 中多跳认知 D2D 通信的任何性能指标，例如中断概率、中断底限和性能损失。