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Jamming Resilient Algorithms for Rendezvous in Cognitive Radio Networks

Rezaei, Roohollah | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 47057 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Aref, Mohammad Reza; Pakravan, Mohammad Reza
  7. Abstract:
  8. Dynamic spectrum access with the aid of cognitive radio (CR) technology is a viable solution to spectrum scarcity. There are many military and emergency applications that require the use of cognitive radio ad-hoc networks (CRAHNs). In these net- works, nodes must first find each other in a wide spectrum and then exchange their desired data. The process of finding each other in a multichannel environment is a challenging task and is usually known as rendezvous. Since rendezvous is the first step in communication, disrupting will disable the nodes from establishing proper communication sessions. That results in a drastic degrade in the performance of the network. Therefore, it is important to analyze the behavior of rendezvous algorithms in a scenario where adversary jammers are trying to prevent a proper communication channel set up. Most of the published rendezvous algorithms do not have the flexi- bility to resist against jamming and their performance will degrade in the presence of a jammer. In this thesis, we propose rendezvous algorithms that have the flexibility to change their behavior in the presence of jammer. In addition, using game theory, we obtain the appropriate strategy to resist against jamming. Using this strategy in a proposed algorithm, the performance in the presence of jammer is considerably improved. In this thesis, we propose eALE algorithm for role-based scenarios and eMC, eRH and eTorus algorithms for non-role based scenarios.The eALE algorithm employs separate procedures for generating the transmitter and receiver sequences. In this algorithm, the receiver remains in a channel and the transmitter searches for it in all channels. This feature allows the algorithm to be flexible in dealing with a potential jammer by allowing it to move away from jammed channels. The proposed algorithm has a much better performance in the presence of jammers while it performs very well in the absence of jammers. We have also proposed a few other algorithms called, eRH, eMC and eTorus. All of these algorithms employ the same procedure for generating their transmitter and receiver sequences. These algorithms provide the flexibility to apply the appropriate strategy and each of them has a unique feature. The eRH algorithm has a simple but flexible structure. The eMC algorithm has a better performance at the cost of a more complicated structure and the eTorus algorithm is based on quorum and guaranties rendezvous in a limited time. The proposed algorithms have a much better performance compared to the previously published rendezvous algorithms with little degradation in their normal (no jamming) operational performance
  9. Keywords:
  10. Cognitive Radio ; Adversary (Jammer) ; Game Theory ; Rendezvous Algorithm

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