Leakage rate‐based untrustworthy relay selection with imperfect channel state information: the outage and security trade‐off analysis

Abstract

This study investigates the effects of the imperfect channel state information on the leakage rate-based untrustworthy relay selection strategies. The investigation considers that the channel state information is imperfect because of the channel estimation errors and also the feedback delay with time-variant channels. The investigation also considers three different types of leakage rate-based selection strategies, which are half-duplex, full-duplex, and hybrid. The investigation also considers a dual-hop one/two-way amplify-and-forward-based half-/full-duplex wireless relaying network in the system model. In addition, in order to mitigate the information leakage, a finite number of friendly jammers are affecting the untrustworthy relay terminals. According to analytical, asymptotic, and Monte–Carlo simulation results, the leakage rate-based selection strategies achieve cooperative diversity order in high signal-to-noise ratio regimes. The channel estimation error causes system coding gain losses in low signal-to-noise ratio regimes. The feedback delay degrades the achievable diversity order from M to 0 and also causes system coding gain losses in high signal-to-noise ratio regimes. In addition, the friendly jammers and loop-interference also degrade the achievable diversity order and also cause system coding gain losses in high signal-to-noise ratio regimes.