Secure Communication via Cooperation and Cooperative Jamming

Hatami, Mohammad | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48133 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Behroozi, Hamid
  7. Abstract:
  8. The broadcast nature of wireless communications makes the propagation medium vulnerable to security attacks such as eavesdropping and jamming from adversarial or unauthorized users. Applying physical layer secrecy approaches will enable the exchange of confidential messages over a wireless medium in the presence of unauthorized eavesdroppers, without using any secret keys. However, physical layer security approaches are typically feasible only when the source-eavesdropper channel is weaker than the source-destination channel. Cooperative jamming can be used to overcome this challenge and increase the secrecy rate. In this thesis, the security of two-phase relaying system with multiple intermediate nodes and in the presence of an eavesdropper is investigated in different scenarios. To enhance the system secrecy rate, a joint cooperative beamforming and jamming combined with relay and jammer selections is proposed. To avoid operational complexity, we consider the minimum number of intermediate nodes that are necessary without losing the performance. Optimal power allocation between the user and jamming signals is analyzed Numerical results demonstrate the advantage of our proposed scheme compared with the scheme with no cooperative jamming
  9. Keywords:
  10. Deletion Channel ; Synchronization Error ; Hidden Markov Model ; Channel Capacity ; Recovery From Random Samples ; Physical Layer ; Cooperation Communication ; Beamforming ; Jamming ; Security

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