Improving the secrecy of cooperative transmissions using unshared jamming

摘要

In this paper, two methods to improve the secrecy of cooperative transmissions using unshared jamming are investigated in which only the source and destination nodes know the jamming signals. The jamming signals are based on unique cipher keys obtained on the high layers. In the first proposed method (SJ protocol), a source combines its secrecy signal with its jamming signal using the power allocation strategy before broadcasting to the relay, destination and even eavesdropper nodes. In the second proposed method (DJ protocol), a source transmits its secrecy signal at the same time a destination transmits its jamming signal. For the secrecy performance evaluation, the asymptotic secrecy outage probability of the end-to-end achievable secrecy rate over flat and block Rayleigh fading channels are studied. Monte-Carlo results are presented to verify the theoretical analyses.