ALMAMATERSTUDIORUM-UNIVERSITÀDIBOLOGNA
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Prof. Roberto Verdone, DEI Ph. +39-051-2093817 e-mail: roberto.verdone@unibo.it
Ref.: Evaluation of Mr. Krzysztof Cichon’s PhD dissertation: “Reliable and Energy-Efficient Spectrum Sensing in Cognitive Radio Systems”
Bologna, February 27, 2017
The dissertation discusses approaches for spectrum sensing in cognitive radio systems.
The introduction gives an overview of the entire work and provides the list of publications published by the Author during his PhD. It is very clear in setting the goals for the work and identifying the main topics discussed. The first Chapter introduces the fundamental background on cooperative and non-cooperative spectrum sensing techniques. In particular the various types of detectors are discussed and the trade-offs included in the general problem of spectrum sensing in wireless networks, are illustrated. The second Chapter deals with autonomous sensing. Both simulation and experimental results are presented and accurately discussed. Chapter III reports considerations on cooperative spectrum sensing techniques. Then, in Chapter IV energy efficient approaches to spectrum sensing are proposed and discussed. Both Chapters III and IV include a large number of numerical results and considerations useful to the design of cognitive radio networks. The last Chapter summarises the main achievements of the PhD.
The dissertation structure is very well organised and presented. Use of English language is very good. Very few and minor typos can be found, which proves a high level of care taken in the preparation of the dissertation. Reading of the work is very easy; the contents can be easily followed and achieved. List of tables, figures, etc. are very accurately prepared. The overall presentation of the work is of the highest level when compared to international standards.
The topic dealt with the thesis is timely, as spectrum sensing during the past years was a topic of great interest to the communication network community. The application of the techniques proposed, is clearly described. The contents of the dissertation can be therefore considered of interest to many researchers in the field.
The thesis claims novelty in defining some spectrum sensing techniques and assessing their performance. The claim is correct (to the best of this evaluator’s knowledge) and the dissertation provides very good insight into the topic. This is also testified by a large number of publications achieved during the PhD, though only one relevant IEEE journal can be found in the list.
The results obtained by Mr. Cichon, either via experimental tests or simulation, are very well presented, easy to understand in most cases, and support very well the thesis of the dissertation stated in the introduction. In fact, some methods proposed in the dissertation for spectrum sensing are more reliable and energy efficient than those previously known from the literature. The results seem to be sound, and even when mathematical forumaltions are proposed, they appear correct and useful.
Overall, the level of accuracy and soundness of the work is very high with respect to international standards. For this reason, this evaluator proposes to approve Mr. Cichon’s dissertation, with distinction.
Faithfully yours, Best regards
Prof. Roberto Verdone
Full Professor in Telecommunications, University of Bologna
