Security Game In Relay-Eavesdropper Channel

In wireless channels the broadcast nature can poses both benefits and penalties for secure communication. In wireless networks the cooperation between wireless nodes can improve the communication efficiency, but the messages that transmitted by the nodes are particularly easily heard by the malicious nodes, so it cause security problem of wireless networks. In recent years, there has been a growing interest in adopting game theory approaches to model wireless communications and signal processing problems. Players in a game select their best strategies to get the optimal utility. In this thesis, we study secure communications of wireless channel from game theory viewpoint.This thesis focuses on the relay-eavesdropper channel in wireless communications based on game theory. We investigate a four terminal network composed of a destination, a source, an eavesdropper and a friendly relay which helps the source to increase secrecy capacity. The source pays the relay for increasing the secrecy capacity; so the relay and source cooperate and compete with each other. In modeling the outcome of the above game we use Stackelberg type of game. Our paper proved the existence of the Stackelberg equilibrium of the game. Simulation results and analysis show the effectiveness of the relay and the tradeoff of the price.Also in this thesis; a coalitional game theory approach is formulated to examine how cooperative nodes would form in a distributed manner and stable outcomes of this coalitional game. Nodes in the same coalition cooperate with each other based on decode-and-forward relaying, namely, TD (Time division) and NTD (Non time division) relay networks. Analysis and numerical results show that nodes cooperate with each other can improve their secure performance.