Wireless Energy Harvesting in a Cognitive Relay Network
Wireless Energy Harvesting in a Cognitive Relay Network
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DOI：
10.1109/twc.2015.2504520
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发表时间：
2016-04-01
影响因子：
10.4
通讯作者：
Elkashlan, Maged
中科院分区：
文献类型：
--
作者：
Liu, Yuanwei;Mousavifar, S. Ali;Elkashlan, Maged
对于能量受限的无线网络，无线能量采集被认为是一种很有前途的能量供应选择。针对具有多个主用户(PU)收发机的底层认知中继网络，提出了一种新的无线能量采集协议。在该协议中，次要节点可以从主要网络(PN)获取能量，同时共享PN的许可频谱。为了评估不同的系统参数对所提出的网络的影响，我们首先推导出满足三个重要功率约束的二级网络(SN)的中断概率的精确表达式：1)次级源(SS)和次级中继(SR)的最大发射功率；2)每个PU接收器允许的峰值干扰功率；以及(3)从每个PU发射机到SR和次级目的地(SD)的干扰功率。为了得到不同参数对SN成功数据传输的影响的实际设计见解，我们推导了延迟敏感和延迟容忍两种传输模式的吞吐量表达式。我们还推导了中断概率和时延敏感吞吐量的渐近闭合表达式，以及当PU收发信机数目趋于无穷大时的时延容忍吞吐量的渐近解析表达式。结果表明，当PU发射机位于SS附近，且距离SR和SD足够远时，中断概率会提高。我们的结果还表明，当PU发射机的数量较多时，PU发射机的干扰的不利影响大于从PU发射机获得的能量的好处。
Wireless energy harvesting is regarded as a promising energy supply alternative for energy-constrained wireless networks. In this paper, a new wireless energy harvesting protocol is proposed for an underlay cognitive relay network with multiple primary user (PU) transceivers. In this protocol, the secondary nodes can harvest energy from the primary network (PN) while sharing the licensed spectrum of the PN. In order to assess the impact of different system parameters on the proposed network, we first derive an exact expression for the outage probability for the secondary network (SN) subject to three important power constraints: 1) the maximum transmit power at the secondary source (SS) and at the secondary relay (SR); 2) the peak interference power permitted at each PU receiver; and 3) the interference power from each PU transmitter to the SR and to the secondary destination (SD). To obtain practical design insights into the impact of different parameters on successful data transmission of the SN, we derive throughput expressions for both the delay-sensitive and the delay-tolerant transmission modes. We also derive asymptotic closed-form expressions for the outage probability and the delay-sensitive throughput and an asymptotic analytical expression for the delay-tolerant throughput as the number of PU transceivers goes to infinity. The results show that the outage probability improves when PU transmitters are located near SS and sufficiently far from SR and SD. Our results also show that when the number of PU transmitters is large, the detrimental effect of interference from PU transmitters outweighs the benefits of energy harvested from the PU transmitters.