In this paper, we analyze the performance of cooperative communications with radio frequency energy harvesting (EH). Different relay selection techniques are studied with optimal harvesting duration. The frame with duration T is decomposed in 3 slots. The duration of first slot is $${\alpha }T$$ α T , and it is dedicated for energy harvesting $$(0<\alpha <1)$$ ( 0 < α < 1 ) . The duration of second and third slots is $$(1-\alpha )T/2$$ ( 1 - α ) T / 2 . The second and third slots are dedicated to source and relay transmission. When harvesting duration, $$\alpha $$ α T, increases, the packet error probability (PEP) decreases since the harvested energy is large. However, the available time for transmission, $$(1-\alpha )T/2$$ ( 1 - α ) T / 2 , decreases. If harvesting duration is small, the PEP is high due to a low harvested energy. In this paper, we choose the value of harvesting duration to enhance the throughput. The proposed optimal harvesting duration allows up to 4 dB gain with respect to $$\alpha =1/3$$ α = 1 / 3 , i.e., same duration used for EH and source transmission.

中文翻译：

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具有最佳无线能量收集的协作通信

在本文中，我们分析了具有射频能量收集 (EH) 的协作通信的性能。研究了具有最佳收获持续时间的不同中继选择技术。持续时间为 T 的帧被分解为 3 个时隙。第一个槽的持续时间是 $${\alpha }T$$ α T ，它专用于能量收集 $$(0<\alpha <1)$$ ( 0 < α < 1 ) 。第二个和第三个槽的持续时间是 $$(1-\alpha )T/2$$ (1 - α ) T / 2 。第二个和第三个时隙专用于源和中继传输。当收集持续时间$$\alpha $$ α T 增加时，由于收集的能量很大，因此包错误概率（PEP）会降低。但是，传输的可用时间 $$(1-\alpha )T/2$$ ( 1 - α ) T / 2 减少了。如果采集持续时间较短，则 PEP 会因采集能量低而较高。在本文中，我们选择收获持续时间的值来提高吞吐量。建议的最佳采集持续时间允许高达 4 dB 增益，相对于 $$\alpha =1/3$$ α = 1 / 3，即用于 EH 和源传输的相同持续时间。