Enhancing Channel Estimation in Cognitive Radio Systems by means of Bayesian Networks

Enhancing Channel Estimation in Cognitive Radio Systems by means of Bayesian Networks P.Demestichas, A.Katidiotis K.Tsagkaris, E.Adamopoulou, K.Demestichas (1) University of Piraeus, Piraeus, Greece Telephone: +30 210 414 27 58, Fax: +30 210 414 25 34 Email: [email protected] Url: www.unipi.gr (2) National Technical University of Athens, Athens, Greece Abstract – This paper proposes enhancements to the channel-state estimation phase of a cognitive radio system. Cognitive radio devices have the ability to dynamically select their operating configurations, based on environment aspects, goals, profiles, preferences etc. The proposed method aims at evaluating the various candidate configurations that a cognitive transmitter may operate in, by associating a capability e.g., achievable bit-rate, with each of these configurations. It takes into account calculations of channel capacity provided by channel-state estimation information (CSI) and the sensed environment, and at the same time increases the certainty about the configuration evaluations by considering past experience and knowledge through the use of Bayesian networks. Results from comprehensive scenarios show the impact of our method on the behaviour of cognitive radio systems, whereas potential application and future work are identified.