Robust secure switching transmission in MISOSE relaying networks with channel uncertainty

In this paper, we investigate the physical layer security of multiple-input single-output single-antenna eavesdropper relaying networks with imperfect channel state information. Different from traditional strategies in relay systems, which would halt the communication if the relay could not decode the signal successfully, we propose a robust secure transmission strategy which switches between cooperative jamming and decoded-and-forward. Our objective is to maximize secrecy rate, given the unavailability of the perfect eavesdropper channel state information, we propose a worst-case robust design based on secrecy rate. In addition, a traditional robust scheme and a non-robust scheme are put forward as benchmarks. Simulation results verify that the proposed scheme based on robust designs can achieve significant security performance gains over other approaches. More interestingly, because of the influence of cooperative jamming, the security performance of non-robust scheme outperforms the traditional robust designs in low transmit power and low channel error coefficient regions.