Duc-Dung Tran

Physical layer secrecy performance over Rayleigh/Rician fading channels

In this paper, we investigate the physical layer secrecy performance of a single-input single-output system that consists of single antenna devices and operates in the presence of a single antenna passive eavesdropper over dissimilar fading channels. In particular, we consider two scenarios in terms of dissimilar fading channel arrangements: the legal/illegal channels are subject to Rayleigh/Rician fading, respectively; and the legal/illegal channels are subject to Rician/Rayleigh fading, respectively. Specifically, analytical expressions for the probability of the existence of a non-zero secrecy capacity and the secrecy outage probability are derived by using statistical characteristics of the signal-to-noise ratio. Numerical results are provided for selected scenarios to illustrate applications of the developed analytical expressions.

Physical Layer Secrecy Performance of Multi-hop Decode-and-Forward Relay Networks with Multiple Eavesdroppers

Today, wireless networks become the most popular way to communicate. However, information can be easily eavesdropped or extracted by eavesdroppers due to the broadcast nature of wireless communication. Multi-hop relay communication systems provide for higher secrecy performance than direct transmission techniques. In this paper, the physical layer secrecy performance of multi-hop decode-and-forward (DF) relay network is investigated in the presence of multiple passive eavesdroppers over Nakagami-m fading channels. To do so, we find out the exact closed-form expressions of existence probability of secrecy capacity and secrecy outage probability by using statistical characteristics of signal-to-noise ratio (SNR). Importantly, these expressions are in more general forms compared to other results in the literature. The proposed results show a quite agreement between numerical analysis and equivalent Monte-Carlo simulations.

Time Reversal SWIPT Networks with an Active Eavesdropper: SER-Energy Region Analysis

This paper analyzes a novel multiple-input single- output (MISO) simultaneous wireless information and power transfer (SWIPT) system model in the presence of an active eavesdropper over the frequency-selective fading channel. In this model, a transmitter applies the time reversal (TR) beamforming technique to combat the fading effects whereas a legitimate user employs a power splitter to jointly receive information and energy, and the active eavesdropper jams the user. Given the system model, the system performance in terms of symbol error rate (SER) and energy harvesting (EH) is analyzed. In particular, we devise a SER-energy region, instead of the conventional rate-energy region, to evaluate system performance of the SWIPT model. A moment generating function (MGF)-based method is presented to exactly derive the average SER analysis. Moreover, the closed-form expression of average effective harvested energy is then provided to complete SERenergy region analysis. Finally, analytical results confirmed by numerical simulations show that the TR technique can support the SWIPT system to notably improve the SER performance whereas the jamming signal can enhance the EH performance.

Unified analysis of energy harvesting–based MIMO relay wireless systems over Nakagami‐m fading channels

In this paper, we consider two-hop multi-input multi-output relay wireless systems with energy harvesting. In each hop, transmit antenna selection/receive antenna selection, transmit antenna selection/maximum ratio combining, or maximum ratio transmission/receive antenna selection is used. Also, an energy-constrained relay harvests energy from the source via either a time switching–based relaying protocol or a power splitting–based relaying protocol. We perform unified analysis of the systems over Nakagami-m fading channels. Specifically, we derive exact closed form expressions for ergodic capacity and throughput (for delay-tolerant transmission mode) and outage probability and throughput (for delay-limited transmission). Optimal energy-harvesting time (in time switching–based relaying protocol–based system) and optimal power-splitting ratio (in power splitting–based relaying protocol–based system) to achieve maximum throughput at high signal-to-noise-ratio are also determined. Moreover, we derive an exact closed form expression for the bit error rate, which facilitates the evaluation of the system performance. Impacts of various multi-input multi-output processing schemes, numbers of equipped antennas, energy-harvesting mechanisms, and transmission modes on the system performance are also examined and discussed. All theoretical analyses are corroborated by simulations.

Secrecy Analysis with MRC/SC-Based Eavesdropper over Heterogeneous Channels

ABSTRACT In the perspective of information-theoretical security, inspired by the heterogeneity between legal and illegal channels, we consider the physical layer secrecy performance of a novel system model with a single antenna employed for both the transmitter and legal receiver, in the presence of a multiple antennas passive eavesdropper over dissimilar fading channels, where the legal/illegal channels are subject to Rayleigh/Nakagami-m and Nakagami-m/Rayleigh fading, respectively. We assume that the eavesdropper employs either maximal-ratio combining or selection combining reception in order to benefit from space diversity. Specifically, the exact closed-form expressions of the probability of existence of secrecy capacity and the secrecy outage probability are derived by utilizing statistical characteristics of the signal-to-noise ratio. Moreover, the delightful results reveal that the secrecy performance achieves a greater level when the Nakagami-m fading is supposed on the main link due to the line of sight component. In final, the analytical results are verified by Monte-Carlo simulation.

Improving network performance by using multiple power-constrained amplify-and-forward relays

In this paper, the performance of radio frequency energy harvesting system with multiple power-constrained relays over Rician/Rayleigh fading channels is studied. This considered system consists of one power and information source, multiple power-constrained relays and one destination. In order to exploit the diversity advantage of cooperative network with low computational complexity, the relays apply the amplify-and-forward (AF) scheme to forward the received signal and the destination uses the selection combining (SC) scheme to receive the information. We derive the exact closed-form expressions of outage probability, throughput and average symbol error probability by using statistical characteristics of signal-to-noise ratio (SNR). Moreover, in order to understand the behavior of this system, we investigate the performance in various system parameters, such as energy harvesting time, relay number, and relay location. Finally, the correctness of the analytical results is confirmed by Monte-Carlo simulation.

Secured energy harvesting networks with multiple power-constrained information sources

The transfer of energy via radio frequency (RF) is the new solution for prolonging the lifetime of wireless networks. This paper investigates the secrecy performance of RF energy harvesting system that consists of one power transfer station, multiple power-constrained information sources and one destination in the presence of one eavesdropper over Rayleigh fading channels. To do so, the exact closed-form expressions of existence probability of secrecy capacity and secrecy outage probability are derived by using statistical characteristics of signal-to-noise ratio (SNR). The numerical results show a quite agreement between numerical analysis and equivalent Monte-Carlo simulations.

Performance Analysis of Two-Way Relaying System with RF-EH and Multiple Antennas

In this paper, we investigate the performance of an amplify-and-forward two-way relay network, in which the relay can harvest the energy from the radio frequency and all channels are subject to Nakagami- \textit{m} fading. In particular, we assume that the relay has a single antenna, while two sources are equipped with multiple antennas. Also, two sources use the maximal ratio transmission (MRT) and maximal ratio combining (MRC) techniques to process the transmit and received signals. Moreover, the multiple access broadcast (MABC) protocol, which can improve the spectrum efficiency, is employed to coordinate the bidirectional communication of the two- way relay network. Given these settings, we derive analytical expressions for the throughput under the delay-limited and delay-tolerant transmission modes and the outage probability. Finally, Monte-Carlo simulations are provided to verify our calculation.

Physical layer secrecy performance of energy harvesting networks with power transfer station selection

This paper investigates the impact of power transfer station selection on the physical layer secrecy performance of radio frequency energy harvesting (EH) networks. The best power transfer station is selected among multiple power transfer stations in EH networks to increase the harvested power of energy constrained users. The exact closed-form expressions of existence probability of secrecy capacity and secrecy outage probability are derived based on using statistical characteristics of Rayleigh fading channels. Numerical and simulation results are presented to confirm the correctness of our analysis.

Effective secrecy-SINR analysis of time reversal-employed systems over correlated multi-path channel

Based on the capability of harvesting the energy of all paths in the multipath environment, time-reversal (TR) transmission technique offers a great potential of low-complexity energy-efficient communications for future wireless network. The TR-employed systems benefit from a significantly reduced leakage of message-bearing signal to unintended users or eavesdroppers. In this paper, we propose a term so-called average effective secrecy signal-to-interference-plus-noise ratio (SINR) which represents the secrecy performance of TR-employed systems. Furthermore, we also consider: (i) the channel correlation between transmit antennas, and (ii) the channel correlation between a legitimate user and an eavesdropper. Accordingly, we derive the average effective secrecy-SINR in a closed-form expression of TR-employed systems. The obtained expression is based on the exact power-averaged expressions of the desired signal and the inter-symbol interference (ISI) components at both the legitimate user and eavesdropper side. The analytical results confirmed by numerical simulations show that the average effective secrecy-SINR metric is preferred to the average secrecy-SINR term in the perspective of measuring secrecy performance over correlated multi-path channel.