University of Malta
Cognitive radios have been advanced as a solution to improve spectral efficiency through opportunistic access of the spectrum by unlicensed users. In order to achieve its objective, a cognitive radio is required to conduct periodic spectrum sensing to avoid interfering with the licensed user of the spectrum. In this paper, the authors examine a multi-channel occupied by a licensed user (primary user) employing slow frequency hopping to access the channel. This method of access presents a challenge to a sensing cognitive radio node since the primary user effectively spreads its signal over the entire wideband and the spectrum holes are rapidly changing.