Cognitive Radio Networks with Energy Harvesting
Cognitive Radio Networks with Energy Harvesting
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DOI：
10.1109/twc.2013.012413.121009
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发表时间：
2013-02
影响因子：
10.4
通讯作者：
Sungsoo Park;Hyungjong Kim;D. Hong
中科院分区：
文献类型：
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作者：
Sungsoo Park;Hyungjong Kim;D. Hong
我们考虑一个认知无线电网络的能量收集的次级发射机，以提高能源效率和频谱效率。本文的目标是确定一个最佳的频谱感知策略，最大限度地提高预期的总吞吐量的能量因果关系约束和冲突约束。能量因果关系约束来自于总消耗能量应该等于或小于总收获能量的事实，而碰撞约束是保护主用户所必需的。我们首先表明，该系统可以分为一个频谱有限的制度和能量有限的制度，这取决于光谱传感器的检测阈值所在。假设无限的电池容量，我们推导出最佳的检测阈值，最大限度地提高预期的总吞吐量的能量因果关系约束和碰撞约束。分析和数值计算结果表明，如果能量到达率低于单次频谱接入的期望能量消耗，则系统是能量受限的。他们还表明，接入占用频谱的概率降低并不总是导致在能量有限的制度下接入空闲频谱的概率降低。
We consider a cognitive radio network with an energy-harvesting secondary transmitter to improve both energy efficiency and spectral efficiency. The goal of this paper is to determine an optimal spectrum sensing policy that maximizes the expected total throughput subject to an energy causality constraint and a collision constraint. The energy causality constraint comes from the fact that the total consumed energy should be equal to or less than the total harvested energy, while the collision constraint is required to protect the primary user. We first show that the system can be divided into a spectrum-limited regime and an energy-limited regime depending on where the detection threshold for the spectrum sensor lies. Assuming infinite battery capacity, we derive the optimal detection threshold that maximizes the expected total throughput subject to the energy causality constraint and the collision constraint. Analytical and numerical results show that the system is energy-limited if the energy arrival rate is lower than the expected energy consumption for a single spectrum access. They also show that a decreasing probability of accessing the occupied spectrum does not always result in decreased probability of accessing the idle spectrum in the energy-limited regime.