Towards Cognitive Radio Systems Main Findings from the COGNAC project

Cognitive radio systems have recently emerged as potential enablers of more efficient use of various resources in future wireless communication systems. Cognitive radio systems can obtain knowledge of their operational environment and internal state, adapt their operations to optimize performance, and learn from the results. This report presents the main results of the COGNAC project in the field of cognitive and opportunistic wireless communication networks. It identifies fundamental techniques for cognitive and opportunistic networks, summarizes the research activities carried out in the COGNAC project, and provides insight into future research directions. Theoretical studies have covered various aspects of cognitive radio techniques, e.g., spectrum-sensing techniques for obtaining information about current spectrum use, dynamic channel access for adapting operations, interference management using power and frequency control, cooperation among devices using game theory, and learning using stored history data. Experimental studies were conducted in the form of spectrum occupancy measurements and the implementation of a cognitive radio test bed. Contributions were made to spectrum regulatory bodies to pave the way for the introduction of cognitive radio techniques into the spectrum regulatory framework. Finally, a roadmap for cognitive radio systems was developed.