Cognitive radio (CR) can improve spectrum utilization by spectrum sharing or cooperation between the pri-mary user and secondary users. It is well known that energy, interference and relay are also three key resources in cogni-tive radio network (CRN). Energy cooperation or sharing between the primary user and secondary user will further pro-mote energy efficiency. Energy harvesting from RF interference signal can turn bane (interference) into a boon (green en-ergy). Secondary user relay data of the primary user can enhance QoS of the primary user, also get some opportunities for their own transmission. Thus, four resources cooperation (spectrum, energy, interference, relay) in CRN will improve simultaneously both spectrum efficiency and energy efficiency, and also increase throughput and QoS. The overviews for collaborative utilization problems of four key resources in CRN was given. Firstly, collaboration models of four key re-sources were analyzed. Then, recent research advances were summarized, including three kinds of resources collaborative utilization (both energy harvesting and relay transmission, both energy cooperation and energy harvesting) and four re-sources collaborative utilization (simultaneous relay transmission, energy harvesting and energy cooperation) in CRN. Further, some potential challenges of four key resources cooperation in CRN were discussed. Finally, some key future research directions was concluded.%在认知无线电网络(CRN)中,主次用户之间可以有效地实现频谱共享(频谱协作),提高频谱利用率;主次用户之间共享频谱会导致相互干扰,从 RF 干扰信号中收集能量,可以变害(干扰)为利(绿色能源);RF能量收集受多种因素影响随机变化而不稳定,通过主次用户之间能量传输(能量协作),可以进一步改进能量的利用效率;次用户帮助主用户协作中继传输数据(信息协作),这既改善了主用户传输性能,也为自己获得了更多的传输机会.系统总结和分析认知无线电网络中多维资源(频谱、能量、干扰、中继)的协作利用问题,主要包括四维资源协作模型与总体研究情况,CRN中能量收集与协作中继,CRN中能量协作和能量收集,CRN中同时能量协作、能量收集和协作中继及研究挑战与未来方向等,对新一代移动通信系统具有重要意义.
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