Secrecy Performance of Wirelessly Powered Wiretap Channels

IEEE Internet Things J.

et al. 2018

Radio frequency energy harvesting (RFEH) is a promising technology to charge unattended Internet of Things (IoT) low-power devices remotely. To enable this, in future IoT system, besides the traditional data access points (DAPs) for collecting data, energy access points (EAPs) should be deployed to charge IoT devices to maintain their sustainable operations. Practically, the DAPs and EAPs may be operated by different operators, and the DAPs thus need to provide effective incentives to motivate the surrounding EAPs to charge their associated IoT devices. Different from existing incentive schemes, we consider a practical scenario with asymmetric information, where the DAP is not aware of the channel conditions and energy costs of the EAPs. We first extend the existing Stackelberg gamebased approach with complete information to the asymmetric information scenario, where the expected utility of the DAP is defined and maximized. To deal with asymmetric information more efficiently, we then develop a contract theory-based framework, where the optimal contract is derived to maximize the DAP's expected utility as well as the social welfare. Simulations show that information asymmetry leads to severe performance degradation for the Stackelberg game-based framework, while the proposed contract theory-based approach using asymmetric information outperforms the Stackelberg game-based method with complete information. This reveals that the performance of the considered system depends largely on the market structure (i.e., whether the EAPs are allowed to optimize their received power at the IoT devices with full freedom or not) than on the information availability (i.e., the complete or asymmetric information).

Section: A Eap Assisted Wireless Energy Harvestingmentioning

confidence: 99%

Incentive Mechanism Design for Wireless Energy Harvesting-Based Internet of Things

Hou

IEEE Internet Things J.

et al. 2018

“…For instance, if the confidential signal is transmitted in the null space of the eavesdropping channel, the eavesdropper is unable to receive any signal. Moreover, by making use of the spatial degrees of freedom offered by the multiple antennas, artificial noise (AN) can be sent together with the desired signal to confuse the eavesdropper [17], [18]. Thus, in the adverse case of short-distance interception, the eavesdropper would suffer from a strong interference signal.…”

Section: Introductionmentioning

confidence: 99%

Exploiting Inter-User Interference for Secure Massive Non-Orthogonal Multiple Access

IEEE J. Select. Areas Commun.

Zhang

Zhong

et al. 2018

Self Cite

This paper considers the security issue of the fifth-generation (5G) wireless networks with massive connections, where multiple eavesdroppers aim to intercept the confidential messages through active eavesdropping. To realize secure massive access, non-orthogonal channel estimation (NOCE) and nonorthogonal multiple access (NOMA) techniques are combined to enhance the signal quality at legitimate users, while the inter-user interference is harnessed to deliberately confuse the eavesdroppers even without exploiting artificial noise (AN). We first analyze the secrecy performance of the considered secure massive access system and derive a closed-form expression for the ergodic secrecy rate. In particular, we reveal the impact of some key system parameters on the ergodic secrecy rate via asymptotic analysis with respect to a large number of antennas and a high transmit power at the base station (BS).Then, to fully exploit the inter-user interference for security enhancement, we propose to optimize the transmit powers in the stages of channel estimation and multiple access. Finally, extensive simulation results validate the effectiveness of the proposed secure massive access scheme.

“…However, harvesting energy from solar, wind or other natural energy depends heavily on location and weather conditions, and so fails to generate stable energy output. It follows that such techniques may not be suitable for powering wireless devices with strict quality of service requirements [2]. An alternative solution, generally referred to as wireless energy transfer (WET), which exploits the radio frequency (RF) signals as a means for energy transportation, has been proposed.…”

Section: Introductionmentioning

confidence: 99%

Improving Secrecy Performance of a Wirelessly Powered Network

Hadley

Ding

et al. 2017

IEEE Trans. Commun.

This paper considers the secrecy communication of a wirelessly powered network, where an energy constrained legitimate transmitter (Alice) sends message to a legitimate receiver (Bob) with the energy harvested from a dedicated power beacon (PB), while an eavesdropper (Eve) intends to intercept the information. A simple time-switching protocol with a time-switching ratio α is used to supply power for the energy constrained legitimate transmitter. To improve the physical layer security, we firstly propose a protocol that combines maximum ratio transmission (MRT) with zero-forcing (ZF) jamming for the case where Eve is passive in the network, so that Alice only has access to the channel state information (CSI) of Bob. Then we propose a protocol that uses a ZF transmitting strategy to minimize the signal-to-noise ratio (SNR) at Eve for the case where Eve is active in the network, so that Alice only has access to the partial CSI of Eve. Closed-form expressions and simple approximations of the connection outage probability and secrecy outage probability are derived for both protocols. Furthermore, the secrecy throughput as well as the diversity orders achieved by our proposed protocols are characterized and the optimal time-switching ratio α and power allocation coefficient β for secrecy throughput maximization are derived in the high SNR regime. Finally, numerical results validate the effectiveness of the proposed schemes.