Study Of Spectrum Sensing Scheduling In Cognitive Radio Network

Spectrum sensing is a key technology in cognitive radio, which is used to detect the spectrum holes and to discover the presence of authorized users. There is an important issue in the MAC layer Spectrum sensing:how to determine the spectrum sensing frequency, namely how to determine the spectrum sensing interval, since it directly affects the efficiency of the spectrum utilization of cognitive users and the interference brought to the authorized users. This paper mainly studies spectrum sensing scheduling algorithm in cognitive radio and verifies its performance in the WLAN.First of all, the basic concept, the research background and the status of cognitive radio and spectrum sensing are introduced. Then the mechanisms of MAC-Layer spectrum sensing management, especially on the sensing period optimization problems, are studied. Moreover, the single-period and the dual-period sensing methods are mathematically analyzed with detailed simulations afterwards. Under the condition that the interference between PUs and SUs is smaller than the maximum interference level tolerated by PUs, simulation results indicate that the dual-period method brings smaller undiscovered opportunities. After that, the disadvantages of dual-period method are analyzed, and the dual-period sensing method based on channel parameters is used in order to improve them. Finally, we build the operational environment for the modified methods in the WLAN. Then we use the historical data collected in this environment to validate the algorithm.