Tuo Yanhong, Zhang Chao
School of Information and Communications Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
Sensors (Basel). 2020 Feb 26;20(5):1273. doi: 10.3390/s20051273.
In this paper, we investigate the outage performance of simultaneous wireless information and power transfer (SWIPT) based Decode-and-Forward (DF) relay networks, where the relay needs to simultaneously forward information for two relaying links, primary relaying link and parasitic relaying link. The primary relaying link is the traditional source-relay-destination relay system. While in the parasitic relaying link, the parasitic source, i.e., Internet-of-Things (IoT) tag, is not connected to the stable power source and thus has to backscatter the signals from the primary source to convey its information. The relay not only harvests energy from Radio Frequency (RF) signals from both sources but also forwards messages to their corresponding destinations. The primary source and destination are unaware of the parasitic backscatter transmission, but the relay and parasitic destination can employ successive interference cancellation (SIC) detector to eliminate the interference from the primary link and detect the message from the parasitic source. In order to investigate the interplay between the primary and parasitic relaying links, the outage probabilities of both relaying links are derived. Besides, the effects of system parameters, i.e., power splitting coefficient, forwarding power allocation coefficient and backscatter reflection coefficient, on the system performance are discussed. Simulation results verify our theoretical analysis. In the meanwhile, it is revealed that the advised relaying system has far larger sum throughput than the one with only primary relaying link and the parasitic relaying link can gain considerable throughput at the cost of negligible degradation of primary throughput.
在本文中，我们研究了基于同时无线信息与能量传输（SWIPT）的解码转发（DF）中继网络的中断性能，其中中继需要同时为两条中继链路转发信息，即主中继链路和寄生中继链路。主中继链路是传统的源 - 中继 - 目的端中继系统。而在寄生中继链路中，寄生源，即物联网（IoT）标签，未连接到稳定电源，因此必须反向散射来自主源的信号来传输其信息。中继不仅从两个源的射频（RF）信号中收集能量，还将消息转发到它们相应的目的端。主源和目的端 unaware of the parasitic backscatter transmission（此处原文有误，推测为“未察觉到寄生反向散射传输”），但中继和寄生目的端可以采用连续干扰消除（SIC）检测器来消除来自主链路的干扰并检测来自寄生源的消息。为了研究主中继链路和寄生中继链路之间的相互作用，我们推导了两条中继链路的中断概率。此外，还讨论了系统参数，即功率分配系数、转发功率分配系数和反向散射反射系数对系统性能的影响。仿真结果验证了我们的理论分析。同时，结果表明所提出的中继系统的总吞吐量远大于仅具有主中继链路的系统，并且寄生中继链路可以在主吞吐量的下降可忽略不计的情况下获得可观的吞吐量。
