The behaviors of heterogeneous users in a geo-location database-assisted cognitive network

Cognitive radio is emerging as a promising technique to improve the utilization of the under-utilized spectrum. The success of cognitive technology relies on the robust detection of the radio environment (e.g., locating the idle channels). Geo-location databases are designed to provide idle unlicensed TV channels list to cognitive users and hence can help reduce the need for energy-intensive processes (such as spectrum sensing). In this paper, the behaviors of cognitive users in a geo-location database-assisted cognitive network is deeply investigated. These cognitive users can subscribe to database and randomly access available channels or perform spectrum sensing to utilize more suitable channels or purchase spectrum from licensed user to access some channels exclusively. The best response of strategy of heterogeneous cognitive users is discussed specifically. Meanwhile, a dynamic updating process in which each cognitive user can change its strategy at every time-slot is presented. The stable condition for this dynamic strategy-selection scheme and the network equilibrium are studied. The numerical simulation results show that the proposed model captures the main factors of the strategy selection process for these heterogeneous cognitive users, significantly reduces the superfluous sensing consumption, and improves system performance to the utmost extent. The proposed method can represent a promising framework for the design of cognitive radio systems.