The influence of noise uncertainty to Energy Detection(ED) of Cognitive Radio(CR) was investigated. The stability of ED was analyzed in order to obtain the stability probability and minimal sampling number. The interruptive detection probability was proposed to reflect the continuance of ED under noise uncertainty. Both the interruptive detection probabilities of single detection and cooperative detection were obtained, and the detection time of ED was also achieved. The detection probability was analyzed in order to achieve its Distribution Function(DFC), and the maximal objective detection probability under the specific interruptive detection probability was estimated through DFC.Simulations showed that the stability of ED could be improved with the increase of sampling number, while the interruptive detection probability increass with the improvment of noise uncertainty or the degrading of the normal Signal-to-Noise Rate(SNR). It also denoted that through cooperative detection, the interruptive detection probability could be degraded.
