A novel adaptive structure of the energy detector applied to cognitive radio networks

The energy detector (ED) is one of the spectrum sensing techniques that is used in the cognitive radio networks to detect the presence of the primary user (PU) in a certain spectrum band. This technique assumes that the PU is either present or absent during the sensing time. However, the ED´s performance degrades in a scenario when the PU is absent and then appears during the sensing time. The ED´s performance is evaluated for this scenario and a novel adaptive ED structure is proposed to improve the detector performance. Analytical performance evaluation of the adaptive ED along with simulation results show that the proposed ED structure improves the probability of detection compared to the conventional ED.