Energy-Efficient Model for Overlay Cognitive Communications
Salvador Perez-Salgado, Enrique Rodríguez-Colina · 2015
Current approaches regarding energy-efficient cognitive radio networks found in the literature aim to optimize the functionalities met by cognitive systems. This is done in order to improve the number of transmitted bits per energy unit and to increase the network lifetime of cognitive devices when they have limited power resources. However, many of these approaches may not fit together when designing a full cognitive radio system. For this reason, a five-layer network model for energy-efficient overlay-based cognitive radio is proposed in this paper. This model includes a set of functionalities necessary to achieve energy-efficiency. We show, by means of simulations, that these functionalities may reduce the number of secondary transmissions by improving the exploitation of primary channels. We also found that, under certain scenarios, the number of transmissions necessary to achieve successful communications can be reduced to the half when the primary network is loaded at 60% of its maximum capacity, when transmissions with low Eb/N0 are combined with adaptive bandwidth channels.