Performance Enhancement for Multihop Harvest-to-Transmit WSNs With Path-Selection Methods in Presence of Eavesdroppers and Hardware Noises

Abstract

Energy-harvesting-based physical-layer security has become a promising technique, as it not only secures information from eavesdropping without upper layer data encryption but also improves the energy efficiency of wireless networks. However, it imposes new challenges, as adversary parties can overhear the transmission of confidential information between the source and destination via a relay. Therefore, the transmit power of the signals must be large enough for energy harvesting, but it must also be small enough to avoid eavesdropping. This is even more challenging with multihop multipath wireless networks. Motivated by these observations, this paper proposes three innovative protocols, namely, the shortest path selection protocol, random path selection protocol, and best path selection protocol. These will enhance the security of multihop multipath randomize-and-forward cooperative wireless sensor networks under the presence of eavesdroppers and hardware impairment, wherein the source node and relay nodes are capable of harvesting energy from beacon for data transmission. Furthermore, we derive exact closed-form expressions and the asymptotic outage probability for each protocol under multiple eavesdropping attacks. The simulation results validate the theoretical results.