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.
