Performance of spectrum sensing using Welch´s periodogram in rayleigh fading channel

In this paper we present theoretical performance evaluation of spectrum sensing with energy detection using Welch´s periodogram for cognitive radio systems. We generalize the theoretical expressions for the probability of detection and the probability of false alarm of energy detection in Rayleigh fading channel to the case of Welch´s periodogram. We verify the theoretical results by simulations both in single node and cooperative sensing scenarios. In particular, cooperation is crucial in fading environment. Protection of primary systems from harmful interference is the key requisite for the introduction of cognitive radio systems into the future spectrum regulatory framework if the systems are deployed on the same spectrum bands. The primary user´s concern is how often it could be susceptible to potential interference from the cognitive radio system, which, as we show, is dependent on the probability of detection. Therefore, performance evaluation and in particular the probability of detection is critical in assessing the potential capabilities of the future cognitive radio systems.