Energy detection of random arrival and departure of primary user signals in Cognitive Radio systems

Spectrum Sensing is a crucial issue in Cognitive radio so that the secondary users are able to access the un-allocated, or temporarily available spectrum holes without interfering with the Primary user. Energy detection (ED) is one of common spectrum sensing techniques in Cognitive Radio. In this paper, an analytical forms are derived for both the detection and false alarm probabilities, using the Bayesian-based ED scheme. The derivations were carried assuming random arrival and departure of the primary user signal during the secondary user´s sensing period. An optimal threshold is suggested to minimize the total detection error rate. The performance gain of the Bayesian-based ED scheme with/without using the optimal threshold is compared to the conventional ED.