IEEE 802.22 is the first worldwide standard for Cognitive Networks (CNs) that exploits unused spectrum of the television broadcast service. An IEEE 802.22 network is also called Wireless Regional Area Network (WRAN). ...IEEE 802.22 is the first worldwide standard for Cognitive Networks (CNs) that exploits unused spectrum of the television broadcast service. An IEEE 802.22 network is also called Wireless Regional Area Network (WRAN). An open issue in cognitive 802.22 networks is represented by the resource distribution among WRANs. In this paper a protocol for radio resource management for CNs in a multichannel environment is presented and analysed. In particular, the contribution of this work is a resource sharing method to schedule the WRAN access to the available channels in a community made by two o more coexisting WRANs. The method adapts to the continuous changes of the spectrum availability due to necessity of vacating a channel in case of the incumbent primary users. Moreover, the introduced allocation scheme allows to divide the available band in a proportional way to the cognitive user spectrum demands, taking into account the issue of spatial diversity, i.e. the case where the channel coverage area is not uniform. The effectiveness of the proposed multichannel scheme is proved through simulations. The results compared favorably with other methods already known in literature and show that the proposed algorithm optimize the spectral efficiency, keeping high fairness as demonstrated computing the Jain’s index.展开更多
国际标准化团体IEEE将于2004年10月正式成立IEEE802．22工作组。IEEE802．22别名称为“Wireless Regional Area Network(WRAN．无线区域网络)”。该工作组的目的是使用一种称为“认知无线电(Cognitive Radio)”的技术，将分配给电视广播...国际标准化团体IEEE将于2004年10月正式成立IEEE802．22工作组。IEEE802．22别名称为“Wireless Regional Area Network(WRAN．无线区域网络)”。该工作组的目的是使用一种称为“认知无线电(Cognitive Radio)”的技术，将分配给电视广播的VHF／UHF频带(北美为54MHz-862MHz)的频率用作宽带访问线路。这是继2002年实现民用的“UWB”之后又一新的无线频率应用技术。展开更多
The specification of IEEE 802.22 defines the world-wide first cognitive radio (CR) standard. Within a range of 40 MHz to 910 MHz CR systems are allowed to allocate spectrum besides the currently established radio serv...The specification of IEEE 802.22 defines the world-wide first cognitive radio (CR) standard. Within a range of 40 MHz to 910 MHz CR systems are allowed to allocate spectrum besides the currently established radio services like radio and TV broadcasting. In order to fulfill the regulative guidelines of interference limita-tions, a capable spectral sensing and user detection has to be provided. Due to the wide frequency range specified in IEEE 802.22 and the high dynamic range of signals allocated in this band there are high de-mands on the CR receiver’s front-end. Especially the performance requirements on analog-to-digital con-verters increase significantly compared to current wireless systems. Based on measurements taken in this frequency range requirements to CR’s ADCs are figured out. Furthermore, the measurement results are ana-lyzed regarding expectable allocation scenarios and their impacts to spectral sensing. Derived from this re-sults and a comparison of general spectral sensing mechanisms an approach for a CR receiver supporting wide-band sensing is presented. Considering the apriori information resulting from scenario analysis and including adapted information processing in the terminal the ADC’s performance requirements can be re-duced.展开更多
文摘IEEE 802.22 is the first worldwide standard for Cognitive Networks (CNs) that exploits unused spectrum of the television broadcast service. An IEEE 802.22 network is also called Wireless Regional Area Network (WRAN). An open issue in cognitive 802.22 networks is represented by the resource distribution among WRANs. In this paper a protocol for radio resource management for CNs in a multichannel environment is presented and analysed. In particular, the contribution of this work is a resource sharing method to schedule the WRAN access to the available channels in a community made by two o more coexisting WRANs. The method adapts to the continuous changes of the spectrum availability due to necessity of vacating a channel in case of the incumbent primary users. Moreover, the introduced allocation scheme allows to divide the available band in a proportional way to the cognitive user spectrum demands, taking into account the issue of spatial diversity, i.e. the case where the channel coverage area is not uniform. The effectiveness of the proposed multichannel scheme is proved through simulations. The results compared favorably with other methods already known in literature and show that the proposed algorithm optimize the spectral efficiency, keeping high fairness as demonstrated computing the Jain’s index.
文摘国际标准化团体IEEE将于2004年10月正式成立IEEE802．22工作组。IEEE802．22别名称为“Wireless Regional Area Network(WRAN．无线区域网络)”。该工作组的目的是使用一种称为“认知无线电(Cognitive Radio)”的技术，将分配给电视广播的VHF／UHF频带(北美为54MHz-862MHz)的频率用作宽带访问线路。这是继2002年实现民用的“UWB”之后又一新的无线频率应用技术。
文摘The specification of IEEE 802.22 defines the world-wide first cognitive radio (CR) standard. Within a range of 40 MHz to 910 MHz CR systems are allowed to allocate spectrum besides the currently established radio services like radio and TV broadcasting. In order to fulfill the regulative guidelines of interference limita-tions, a capable spectral sensing and user detection has to be provided. Due to the wide frequency range specified in IEEE 802.22 and the high dynamic range of signals allocated in this band there are high de-mands on the CR receiver’s front-end. Especially the performance requirements on analog-to-digital con-verters increase significantly compared to current wireless systems. Based on measurements taken in this frequency range requirements to CR’s ADCs are figured out. Furthermore, the measurement results are ana-lyzed regarding expectable allocation scenarios and their impacts to spectral sensing. Derived from this re-sults and a comparison of general spectral sensing mechanisms an approach for a CR receiver supporting wide-band sensing is presented. Considering the apriori information resulting from scenario analysis and including adapted information processing in the terminal the ADC’s performance requirements can be re-duced.
