A Setting Method and Performance Evaluation of Adaptive Sensing Threshold Based on Power Detection of the Primary User

Both spectrum sensing and intelligent access of the secondary user (SU) are key technologies for cognitive radio. This paper focuses on a novel setting and access control method of adaptive sensing threshold based on power detection of the primary user (PU), on the basis of the analysis of the coexistence model between PU and SU. Mathematical and practical numerical simulations confirm the good performance of spectrum sensing on primary bands in IEEE 802.22 WRAN systems. The results show that the sensing threshold calculated by power detection of PU, not only maintains constant probabilities of missed detection and false alarm, but also obtains the optimum performance of spectrum sensing. The optimal SU´s transmission power, adaptively according to sensing threshold, enables both SU and PU to coexist in the same channel without interfering each other.