University of Jyväskylä

Dissertation: 7.6. Cooperative Spectrum Sensing Schemes for Future Dynamic Spectrum Access Infrastructures (Abdi)

Start date: Jun 07, 2016 12:00 PM

End date: Jun 07, 2016 03:00 PM

Location: Mattilanniemi, Agora Auditorio 3

M.Sc. Younes Abdi Mahmoudaliloo defends his doctoral dissertation in Information Technology ”Cooperative Spectrum Sensing Schemes for Future Dynamic Spectrum Access Infrastructures”. Opponent Professor Markku Juntti (University of Oulu) and custos Professor Tapani Ristaniemi (University of Jyväskylä).

Efficient utilization of available resources is a vital requirement in designing modern communication systems. Limited battery lifetime of today’s so-called smart wireless devices and the global warming effect are among the challenges which force engineers to reduce the energy consumption of wireless networks. On the other hand, the current dramatic growth rate in the number of bandwidth-hungry mobile systems and applications along with adherent scarcity in the available spectrum resources necessitates developing advanced spectrum-efficient communication techniques. Consequently, cognitive radio technology has been of great interest as an important implementation platform for green and spectrum-efficient wireless communication scenarios.

In cognitive radios, the information obtained from the surrounding radio environment is often an essential material for creating knowledge about the available resources and to apply that knowledge towards realizing reliable and efficient wireless communications. Consequently, since the spectrum sensing functionality in cognitive radios provides information about the availability of the radio spectrum, which is considered as one of the most valuable communication resources, developing better spectrum sensing techniques is of critical importance and directly affects the performance of cognitive radio networks in many different aspects.

In this dissertation, we first overview the notions of dynamic spectrum access and cognitive radio, in particular, in order to highlight the role, impact, and importance of this new communication paradigm in emerging wireless technologies. Specifically, we discuss the current state of spectrum utilization, new rules and regulations facilitating better spectrum use and how cognitive radios are developed as powerful assets to cope with the ever-increasing demand for higher levels of capacity, reliability, flexibility, and interoperability in wireless communication networks.

As the core of this dissertation, we investigate spectrum sensing as a major capability in cognitive radios and discuss a number of significant design challenges in spectrum sensing for cognitive radio networks. These challenges cover a diverse collection of functionalities which, as a whole, enable cognitive radio networks to discover transmission opportunities in the underutilized parts of the radio spectrum and increase the efficiency of spectrum use without compromising the integrity of the legacy wireless networks. In addition, we discuss how cooperative communication techniques are used to enhance the reliability of the spectrum sensing through better utilization of the spatial/user diversities in cognitive radio networks. We study various phases in the commonly-used cooperative sensing architectures in order to build a solid understating of the role of different building blocks in this cooperation process. The analytical investigations in this dissertation along with their supporting simulation results demonstrate that, design of spectrum sensing in cognitive radio networks, in general, involves dealing with various processes which often are different in nature and impose contradicting requirements. Hence, joint design of these processes often leads to a diverse collection of signal processing challenges and we show that joint consideration of different processes involved in cooperative sensing can lead to significant performance gains.

Contact information
Younes Abdi, tel: 040 8054892,

The dissertation is published in the series Jyväskylä Studies in Computing, number 238, 128 p., Jyväskylä 2016, ISSN: 1456-5390; 238, ISBN: 978-951-39-6653-9. It is available at the University Library’s Publications Unit, tel. +358 40 805 3825, Available online:

Younes Abdi received his B.Sc. degree from the University of Tabriz in Iran, in 2008 and his M.Sc. degree from Tarbiat Modares University in Tehran, Iran, in 2011, both in Electrical Engineering. From October 2010 to November 2011, he was with Radio Communications Group at Iran Telecommunications Research Center (ITRC), Tehran, Iran, working on the standardization and regulatory issues of cognitive radio networks. In 2012, he joined the Faculty of Information Technology at the University of Jyväskylä. He is also a member of working group 1900.1 in the IEEE Dynamic Spectrum Access Networks Standards Committee (DySPAN-SC).

The research has been financially supported by Finnish National Graduate School in Electronics, Telecommunications, and Automation (GETA) and Jyväskylä Doctoral Program in Computing and Mathematical Sciences (COMAS).

More information

Younes Abdi Mahmoudaliloo
+358 (0)40 805 4892
Filed under: