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

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.

Konstantinos P. DemestichasEmail:

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Panagiotis Demestichas   was born in Athens, Greece, in 1967. He received the Diploma and the Ph.D. degrees in Electrical and Computer Engineering from the National Technical University of Athens (NTUA). From December 2007 he is Associate Professor at the University of Piraeus, in the department of Technology Education and Digital Systems. From September 2002–December 2007 he was Assistant Professor at the University of Piraeus, in the department of Technology Education and Digital Systems. From 1993–2002 he has been with the Telecommunications Laboratory in NTUA. From February 2001 until August 2002 he was adjunct lecturer at NTUA, in the department of Applied Mathematics and Physics. From September 2000 until August 2002 he taught telecommunication courses, in the department of Electronics of the Technological Education Institute of Piraeus. He leads the laboratory of Telecommunication Networks and Services, of the University of Piraeus. At the international level he actively contributes to research funded from various EU frameworks for research and technological development. Most of his current activities focus on the FP7 “End-to-End Efficiency” (E³) project, which is targeted to the introduction of cognitive systems in the wireless B3G world. He has actively participated to projects of the IST/FP6, IST/FP5, ACTS, RACE II, BRITE/EURAM and EURET frameworks. In IST/FP6, in the time frame 2004–2007, he participated to the “End-to-End Reconfigurability” (E²R) project, where he was leader of the workpackage on “proof of concept and validation”. In IST/FP5 he was involved in the management of the MONASIDRE project, which was targeted to the collaboration of UMTS, WLAN and DVB technologies, in the context of a B3G infrastructure. He is the chairman of Working Group 6 (WG6), titled “Cognitive Wireless Networks and Systems”, of the Wireless World Research Forum (WWRF). He is involved in standardisation in the context of ETSI and IEEE SCC4 He has extensive collaborations with Greek companies of the IT and telecommunications sectors. His research interests include the design, management and performance evaluation of mobile and broadband networks, service and software engineering, algorithms and complexity theory, and queuing theory. He is a member of the IEEE, ACM and the Technical Chamber of Greece.

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Apostolos Katidiotis   was born in Maroussi, Athens in November, 1980. He received his diploma in 2003 from the Department of Technology Education and Digital Systems in University of Piraeus. Since September 2003 he is a research engineer and Ph.D. candidate at the University of Piraeus, Laboratory of Telecommunication Networks and Services. His research interests include the design, management and performance evaluation of mobile and broadband networks, reconfigurable and cognitive systems, service and software engineering.

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Kostas A. Tsagkaris   was born in Lamia, Greece. He received his diploma (in 2000) and his Ph.D. degree (in 2004) from the School of Electrical Engineering and Computer Science of the National Technical University of Athens (NTUA). His Ph.D. thesis was awarded in 2005 “Ericsson’s awards of excellence in Telecommunications”. He has been involved in many international and national research projects, especially working on the area of wireless networks resource management and optimization. He has been involved in many international and national research projects, especially working on the area of wireless networks resource management and optimization. Since January 2004 he is working as a senior research engineer at the Department of Technology Education and Digital Systems of the University of Piraeus. From September 2005 he is an adjunct Lecturer in the undergraduate and postgraduate programs of the Department of Technology Education and Digital Systems of the University of Piraeus. His current interests are in the design and management of wireless reconfigurable networks, optimization algorithms, learning techniques and software engineering. Dr. Tsagkaris is a member of IEEE, ACM and a member of the Technical Chamber of Greece.

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Evgenia F. Adamopoulou   (jenny@cn.ntua.gr) was born in Athens, Greece, on November 15, 1982. She received her Dipl.- Ing. degree from the School of Electrical and Computer Engineering of the National Technical University of Athens (NTUA) in 2005. She is currently working toward a Ph.D. degree at the same institution. Her research interests include wireless communication systems, information systems and telecommunication software design and implementation. She is a member of the Technical Chamber of Greece.

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Konstantinos P. Demestichas   (cdemest@cn.ntua.gr) was born in Athens, Greece, on May 19, 1982. He received his Dipl.-Ing. degree from the School of Electrical and Computer Engineering of the National Technical University of Athens (NTUA) in 200 He is currently working toward a Ph.D. degree at the same institution. His research interests include wireless communication systems, information systems and telecommunication software design and implementation. He is a member of the Technical Chamber of Greece.