A measurement algorithm for frequency agility in cognitive radio

Nowadays, radio systems have to use the spectrum resource more intensely than in the past to meet the demanding expectations of the users. Several studies have demonstrated that portions of radio spectrum are not in use for significant periods of time, showing the necessity to design a more flexible way to manage the spectrum resource with respect to the traditional frequency allocation policy. Cognitive radios systems have been conceived to enable such flexible spectrum allocation, making more intensive and efficient spectrum use. This capability is usually called frequency agility. In literature, several spectrum sensing methods have been proposed, which promise good performance even when applied to detect very weak signals. Nevertheless, even though they meet the spectrum sensing capability requirements, they do not seem to satisfy the frequency agility capability requisites. In this framework, the paper proposes a novel measurement algorithm able to meet those requirements. Major strength of the proposal is the ability to correctly operate even in scenarios characterized by very low signal-to-noise ratios. The assessment campaign has shown the efficacy and usefulness of the proposed algorithm.