Improving secrecy cooperation transmissions using power allocation strategy

Abstract

In wireless communication, the secrecy of data transmission is an important objective, and especially when eavesdropper nodes are near source nodes. In this case, eavesdropper nodes can wiretap easily any information from the source nodes. In this paper, an approach method to improve secrecy cooperation transmissions using combined signals is investigated in which data and jamming signals are combined at a source node based on power allocation strategy. The secrecy system performances are evaluated using asymptotic secrecy outage probabilities of end-to-end achievable secrecy rates over flat and block Rayleigh fading channels. Monte-Carlo simulation results are presented to verify the theoretical analyses. The main contributions of the proposed protocol are as follows. First, the jamming signals at the source node are secret against a relay and an eavesdropper node. Second, an amplify-and-forward method is applied so the relay cannot know the secrecy signal along with the jamming signals. Third, by transmitting the jamming signals from the source node, the proposed protocol prevents wiretapping by nearby eavesdropper. Finally, the asymptotic analysis is valid with the simulation result evaluating the secrecy performance of the proposed protocol.