The IEEE 802.22 standard based on wireless Cognitive Radio (CR) is an optimal solution to resolve the inefficient spectrum utility problem. In this paper, we focus on the spectrum allocation in IEEE 802.22 mesh networ...The IEEE 802.22 standard based on wireless Cognitive Radio (CR) is an optimal solution to resolve the inefficient spectrum utility problem. In this paper, we focus on the spectrum allocation in IEEE 802.22 mesh networks and propose a new graph-theory algorithm. The algorithm aims at two objectives: one is the sum of the allocated channel bandwidth is maximum, and the other is the number of users can be active simultaneity is maximum. In this proposed algorithm, the topology of network was modeled as a general graph and could be transformed into a weighted complete bipartite-graph by three processes. The simulations show that the presented algorithm can improve the performance of spectrum allocation.展开更多
Cognitive radio(CR) can bring about remarkable improvement in spectrum utilization.Different cognition cycles have been proposed in recent years.However,most of the existing works only emphasize functional or operatio...Cognitive radio(CR) can bring about remarkable improvement in spectrum utilization.Different cognition cycles have been proposed in recent years.However,most of the existing works only emphasize functional or operational aspects of cognition cycle,regardless of other indispensable aspects and the connection between them.To deal with the emerging situation of "data rich,information vague,knowledge poor" in cognitive radio networks(CRNs),we propose the hierarchical cognition cycle(HCC) as a new transdisciplinary research field in this paper.HCC investigates a fundamental problem,which is how to manage available resources in the complex environment to meet various demands in CRN.A comprehensive theoretical framework of HCC is established in terms of the core,the essence loop,the function loop,the operation loop,and the external loop of HCC.The reduction of uncertainty in CRN is studied and several new metrics in HCC are defined.Furthermore,a few research challenges ahead are presented as well.展开更多
文摘The IEEE 802.22 standard based on wireless Cognitive Radio (CR) is an optimal solution to resolve the inefficient spectrum utility problem. In this paper, we focus on the spectrum allocation in IEEE 802.22 mesh networks and propose a new graph-theory algorithm. The algorithm aims at two objectives: one is the sum of the allocated channel bandwidth is maximum, and the other is the number of users can be active simultaneity is maximum. In this proposed algorithm, the topology of network was modeled as a general graph and could be transformed into a weighted complete bipartite-graph by three processes. The simulations show that the presented algorithm can improve the performance of spectrum allocation.
基金supported by the National Key Basic Research Program of China(973 Program) under Grant No.2009CB320400the National Natural Science Foundation of China under Grants No.60932002,61172062,61301160the Natural Science Foundation of Jiangsu,China under Grant No.BK2011116
文摘Cognitive radio(CR) can bring about remarkable improvement in spectrum utilization.Different cognition cycles have been proposed in recent years.However,most of the existing works only emphasize functional or operational aspects of cognition cycle,regardless of other indispensable aspects and the connection between them.To deal with the emerging situation of "data rich,information vague,knowledge poor" in cognitive radio networks(CRNs),we propose the hierarchical cognition cycle(HCC) as a new transdisciplinary research field in this paper.HCC investigates a fundamental problem,which is how to manage available resources in the complex environment to meet various demands in CRN.A comprehensive theoretical framework of HCC is established in terms of the core,the essence loop,the function loop,the operation loop,and the external loop of HCC.The reduction of uncertainty in CRN is studied and several new metrics in HCC are defined.Furthermore,a few research challenges ahead are presented as well.
