دانلود رایگان مقاله انگلیسی پروتکل های ردیابی دو طرفه بی سیم برای بهینه سازی امنیت لایه های فیزیکی - IEEE 2018

Abstract

This paper considers a two-way relay network, in which two sources exchange data through a relay and a cooperative jammer transmits an artificial noise (AN) while a number of nearby eavesdroppers overhear to recover data from both sources. The relay harvests energy from the two source signals and the AN, and then, uses this harvested energy to forward the received signals to the two sources. Each source eliminates its own signal from the relaying signal by self-cancellation and then decodes the data signal received from the other source. For this wireless-powered two-way relay system, we propose two secure relay protocols based on power splitting and time switching techniques. The two protocols are power splitting-based two-way relaying (PS-TWR) and time switching-based two-way relaying (TS-TWR), in which the relay respectively controls the power splitting ratio (ρ) and time switching ratio (α), in order to achieve a balance between the data receiving and the energy harvesting. The optimal values of ρ and α for each protocol are found analytically to maximize the minimum guaranteed secrecy capacity (C min S ) considering multiple eavesdroppers in high signal-to-noise ratio environments. Numerical results show that both the PS-TWR and TS-TWR protocols using the optimized values of ρ and α achieve the near-optimal C min S no matter how many eavesdroppers exist anywhere. Comparisons of the two protocols in various scenarios also show that PS-TWR achieves better C min S than TS-TWR because PS-TWR inherently has a shorter vulnerable time for eavesdropping than TS-TWR.

VI. CONCLUSIONS

We investigated a wireless-powered two-way relay system with a cooperative jammer to maximize the minimum guaranteed secrecy capacity in the existence of multiple eavesdroppers. We proposed PS-TWR and TS-TWR protocols that adaptively control the power splitting ratio (ρ) and time switching ratio (α), respectively, according to the network condition. We proved the concavity of the secrecy capacity for each source with respect to ρ and α under the assumption of high SNR and derived optimal values of ρ and α to maximize the minimum guaranteed secrecy capacity (C min S ). Analysis and simulation results showed that the proposed PS-TWR and TS-TWR protocols using the derived ρ ∗ and α ∗ achieve the near-optimal C min S in various network environments no matter how many eavesdroppers exist anywhere. In addition, the comparison of PS-TWR and TS-TWR revealed that PSTWR is well protected against the eavesdropping than TSTWR. We expect the proposed wireless-powered two-way re- laying protocols to show promise as alternatives for resolving not just energy deficiency but also information security in energy-limited wireless networks. To extend this study, we can consider the cooperation among multiple eavesdroppers to decode the received signal together and we leave this issue for further study.