This paper investigates secure transmission in a wireless powered communication network (WPCN) with an energy harvesting (EH) source configured with multiple antennas. In the WPCN, the EH source harvests energy from the radio frequency (RF) signals broadcasted by a power beacon (PB), and purely relies on the harvested energy to communicate with the destination in the presence of passive eavesdroppers. It is noteworthy that the RF-EH source is equipped with a finite energy storage to accumulate the harvested energy. To enhance the security, we propose an energy-aware transmit antenna selection (EATAS) scheme. According to the energy status and the channel quality, the source adaptively decides to transmit confidential information or harvest RF energy. For evaluating the secrecy performance, we first study the evolution of the energy storage, and then derive the analytical expressions of connection outage probability (COP), secrecy outage probability (SOP) and effective secrecy throughput (EST). Numerical results demonstrate that our proposed scheme outperforms the existing accumulate-then-transmit (ATT) scheme.
This paper investigates secure transmission in a wireless powered communication network (WPCN) with an energy harvesting (EH) source configured with multiple antennas. In the WPCN, the EH source harvests energy from the radio frequency (RF) signals broadcasted by a power beacon (PB), and purely relies on the harvested energy to communicate with the destination in the presence of passive eavesdroppers. It is noteworthy that the RF-EH source is equipped with a finite energy storage to accumulate the harvested energy. To enhance the security, we propose an energy-aware transmit antenna selection (EATAS) scheme. According to the energy status and the channel quality, the source adaptively decides to transmit confidential information or harvest RF energy. For evaluating the secrecy performance, we first study the evolution of the energy storage, and then derive the analytical expressions of connection outage probability (COP), secrecy outage probability (SOP) and effective secrecy throughput (EST). Numerical results demonstrate that our proposed scheme outperforms the existing accumulate-then-transmit (ATT) scheme.
This paper investigates secure transmission in a wireless powered communication network (WPCN) with an energy harvesting (EH) source configured with multiple antennas. In the WPCN, the EH source harvests energy from the radio frequency (RF) signals broadcasted by a power beacon (PB), and purely relies on the harvested energy to communicate with the destination in the presence of passive eavesdroppers. It is noteworthy that the RF-EH source is equipped with a finite energy storage to accumulate the harvested energy for the future usage. Moreover, due to energy-constraint and complexity- limitation, the multi-antenna source is only configured with a single RF-chain. To enhance the security for the WPCN, we propose two adaptive transmission schemes, i.e., energy-aware transmit antenna selection (EATAS) and energy-aware differential spatial modulation (EADSM). According to the energy status and the channel quality, the source adaptively decides whether to transmit confidential information or harvest RF energy. To evaluate the secrecy performance of the proposed schemes, we first study the evolution of the energy storage, and then derive the analytical expressions of connection outage probability (COP), secrecy outage probability (SOP) and efficient secrecy throughput (EST). Numerical results demonstrate that our proposed schemes outperform the existing schemes, i.e., time-switching based TAS (TS-TAS) and accumulate-then-transmit (ATT). And, increasing the transmit power of the PB or the capacity of the source's energy storage is helpful to improve the secrecy performance. Moreover, there exists an optimal transmission rate for each proposed scheme to achieve best secrecy performance.
This paper investigates secure transmission in a wireless powered cooperative communication network (WPCCN) over Nakagami-mfading channels, where multiple intermediate energy harvesting (EH) nodes with finite energy storage are deployed to assist the secure transmission between source and destination in the presence of an eavesdropper. Specifically, the intermediate EH nodes first harvest and accumulate energy from the source's signal and then forward the confidential signal or emit jamming signal to interfere the eavesdropper according to actual requirements. In order to exploit the intermediate EH nodes for secure improvement, considering both energy storage status and channel gains, three relay-and-jammer selection schemes at the intermediate nodes are proposed, namely: energy threshold based best-relay and random-jammer (ETBR), energy threshold based random-relay and best-jammer (ETRB), and energy threshold based best-relay and best-jammer (ETBB). For understanding the impact of critical parameters on the secrecy performance, we first capture the evolution of the EH nodes’ storages using finite-state Markov chain (FSMC) and then derive the analytical expressions for hybrid outage probability (HOP) and secrecy throughput (ST). Furthermore, numerical results demonstrate that our proposed selection schemes outperform the existing schemes (bR-rJ, rR-bJ, bR-bJ) due to the consideration of energy accumulation and storage status. In addition, there is a suitable value of the energy threshold for each proposed scheme to achieve the optimal secrecy performance.
This paper considers a wireless powered communication network, where a multiantenna power beacon (PB) is employed to assist an energy constrained source to establish secure communications with a destination in the presence of multiple eavesdroppers. We propose a two-phase communication protocol termed as accumulate then transmit to enhance network secrecy. In the energy harvesting phase, the PB transfers radio frequency energy to charge the source; then in the information transmission phase, the PB acts as a friendly jammer to protect the source transmission against eavesdropping. We study the dynamic energy state transitions at the source using an energy discretization method and a finite-state Markov chain. Closed-form expressions are derived for connection outage probability, secrecy outage probability, and effective secrecy throughput, with the aim to evaluate both reliability and security of the proposed protocol. Furthermore, numerical results reveal the impacts of various system parameters on the secrecy performance and demonstrate the superior performance of our proposed protocol over an existing scheme.
In this paper, we present a secrecy outage performance analysis of wireless powered communication networks with multiple eavesdroppers, where an energy-limited information source with multiple antennas harvests the radio frequency (RF) energy from a dedicated power beacon (PB) before transmission. To exploit the benefits of multiple antennas at source, two popular multi-antenna transmission schemes, i.e., maximal ratio transmission and transmit antenna selection, are investigated for two intercepting ways at Eves, i.e., non-colluding and colluding scenarios, respectively. Specifically, adopting the time-switching protocol at PB, we derive exact and asymptotic closed-form expressions of the secrecy outage probability for both two transmission schemes taking into account the outdated channel state information (CSI). From our analysis, several important concluding remarks are obtained as follows: a) Full secrecy diversity order can be achieved by both two transmission schemes with no feedback delay, however, it reduces to zero in the presence of feedback delay; b) MRT scheme always outperforms TAS scheme with no feedback delay. However, TAS scheme achieves a similar performance as MRT scheme or even better in moderate and even serious feedback delay conditions.
The paper focuses on investigating secure transmission in wireless powered communication networks (WPCN) that involve multiple energy-constrained relays and one energy-constrained source.The energy is harvested from a power beacon (PB) while operating in the presence of a passive eavesdropper.The study primarily aims to achieve energy-efficient secure communications by examining the impact of channel estimation on the secrecy performance of WPCN under both perfect and imperfect CSI scenarios.To obtain practical insights on improving security and energy efficiency, we propose closed-form expressions for secrecy outage probability (SOP) under the linear energy harvesting (LEH) model of WPCN.Furthermore, we suggest a search method to optimize the secure energy efficiency (SEE) with limited power from PB.The research emphasizes the significance of channel estimation in maintaining the desired performance levels in WPCN in real-world applications.The theoretical results are validated through simulations to ensure their accuracy and reliability.
This paper investigates the physical layer secrecy performance of radio frequency (RF) energy harvesting (EH) relaying networks based on the combination of time switching-adaptive power splitting (TSAPS) and best relay selection (BRS) schemes. Specifically, the system consists of one source, one destination and multiple energy-constrained decode-and-forward (DF) relays which help the source transmit information to the destination, in the presence of a passive eavesdropper. In this setting, the relays harvest RF energy from the source signal to power their relaying transmission, in which power splitting ratio self-adjustment policy and best relay selection scheme are utilized. To characterize the secrecy performance, the exact closed-form expressions of secrecy outage probability for random relay selection and best relay selection are derived. In addition, the comparison to random relay selection is presented to verify the efficiency in terms of secrecy outage probability of the proposed protocol. Finally, the numerical and simulation results are also provided to evaluate the impact of the key parameters on the secrecy performance and confirm the correctness of our analysis.