标题：Cognitive Relaying With Wireless Powered Primary User
作者：Zhai C.; Chen H.; Yu Z.; Liu J.
作者机构：[Zhai, C] School of Information Science and Engineering, Shandong University, Qingdao 266237, China and National Mobile Communications Research Labora 更多
来源：IEEE Transactions on Communications
关键词：Cognitive relaying; energy harvesting; spectrum sharing; wireless power transfer
摘要：Integrating energy harvesting (EH) into cognitive radio networks can promisingly sustain the operations of energylimited terminals and improve the spectral efficiency. Traditionally, secondary users (SUs) are normally assumed to harvest energy from the transmissions of primary users (PUs). In contrast, we consider an alternative scenario with a PU harvesting energy from its access point (AP) and SUs, and propose a cognitive relaying scheme. Each time block is divided into two periods. In the first period, AP transfers wireless energy to PU, and meanwhile an SU and its relay cooperatively transmit secondary data using peak powers, where the resultant interference can help boost the amount of energy harvested by PU. In the second period, PU transmits data to AP using the harvested energy, and meanwhile SU and its relay continue to cooperatively transmit secondary data using controlled powers under the interference constraint at AP. We analyze the throughput of both systems and reveal the impacts of key parameters. Numerical results show that our scheme can greatly improve the system spectral efficiency while satisfying the interference constraint of PU. IEEE