Li Qiang, Zhang Xueyan, Pandharipande Ashish, Ge Xiaohu, Gharavi Hamid
School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan 430074, China.
Signify, 5656 AE Eindhoven, The Netherlands.
IEEE Trans Cogn Commun Netw. 2019;5(3). doi: 10.1109/tccn.2019.2911680.
In this paper, cooperative spectrum sharing is considered between a primary user (PU) and a secondary user (SU), where the off-the-grid secondary transmitter (ST) serves as a cognitive relay to forward both the received primary and secondary signals by exploiting simultaneous wireless information and power transfer (SWIPT). Based on a two-phase relaying model, power splitting is adopted by the ST for energy harvesting and information processing in the first phase. Next, the harvested energy at the ST is used to amplify-and-forward a linearly weighted combination of the primary and secondary signals, in the second phase. To enhance the reliability of the system and utilize the energy harvested more wisely, an energy-aware retransmission (EAR) scheme is proposed in the first phase to guarantee that a certain minimum amount of energy is collected by the ST before launching the second phase. Both outage and throughput performances are theoretically analyzed for the PU and the SU. Simulation results demonstrate that a win-win relationship is built between the PU and the SU under proper parameter configurations, and the proposed EAR scheme can bring additional performance gains in unfavorable conditions imposed under and
本文考虑了主用户（PU）和次用户（SU）之间的协作频谱共享，其中离网次发射机（ST）作为认知中继，通过利用同时无线信息与功率传输（SWIPT）来转发接收到的主信号和次信号。基于两阶段中继模型，ST在第一阶段采用功率分割进行能量收集和信息处理。接下来，ST在第二阶段利用收集到的能量对主信号和次信号的线性加权组合进行放大转发。为提高系统的可靠性并更明智地利用收集到的能量，在第一阶段提出了一种能量感知重传（EAR）方案，以确保ST在启动第二阶段之前收集到一定量的最小能量。对PU和SU的中断和吞吐量性能进行了理论分析。仿真结果表明，在适当的参数配置下，PU和SU之间建立了双赢关系，并且所提出的EAR方案在 和 施加的不利条件下可以带来额外的性能增益。
