Improving Security-Reliability Tradeoff Through Joint Relay and Jammer Selection

This chapter explores the employment of joint relay and jammer selection for improving the security-reliability tradeoff (SRT) of wireless transmission from a source to a destination with the help of multiple relays and jammers in the presence of an eavesdropper. We present a joint relay and jammer selection scheme for protecting the source transmission against eavesdropping. To be specific, a relay is selected among multiple relay candidates to assist the source transmission to the destination, while a friendly jammer is employed to emit the artificial noise for preventing the eavesdropper from decoding the source transmission. For comparison purposes, the conventional pure relay selection and pure jammer selection are considered as benchmark schemes. We derive closed-form expressions of both the intercept probability and outage probability for the conventional pure relay selection and pure jammer selection as well as the proposed joint relay and jammer selection schemes over Rayleigh fading channels. Numerical results illustrate that the SRT performance of proposed joint relay and jammer selection is better than that of the conventional pure relay selection and pure jammer selection, showing the SRT enhancement of employing the relay and jammer selection. It is also shown that with an increasing number of relays and jammers, the SRT of wireless communications relying on the proposed joint relay and jammer selection is improved significantly.