In recent years, simultaneous wireless information and power transfer (SWIPT) has attracted people's research interest, but many researchers only consider one of the secrecy throughput and harvested energy. In this paper, we optimize the secrecy throughput and improve the utilization of the harvested energy in a certain way with a based beamforming artificial noise aided SWIPT system over a Rayleigh fading channel. We investigate the relationship between the secrecy outage probability and the target secrecy rate and the power allocation ratio through formula derivation and simulation results. Then we propose an algorithm of joint power allocation and splitting to achieve the maximum secrecy throughput. Furthermore, we investigate the maximum secrecy throughput in the beamforming mode and that in broadcast mode. The simulation results show that the use of beamforming technique can greatly improve the performance of the secrecy throughput and the harvested energy.
In recent years, simultaneous wireless information and power transfer (SWIPT) has attracted people's research interest, but many researchers only consider one of the secrecy throughput and harvested energy. In this paper, we optimize the secrecy throughput and improve the utilization of the harvested energy in a certain way with a based beamforming artificial noise aided SWIPT system over a Rayleigh fading channel. We investigate the relationship between the secrecy outage probability and the target secrecy rate and the power allocation ratio through formula derivation and simulation results. Then we propose an algorithm of joint power allocation and splitting to achieve the maximum secrecy throughput. Furthermore, we investigate the maximum secrecy throughput in the beamforming mode and that in broadcast mode. The simulation results show that the use of beamforming technique can greatly improve the performance of the secrecy throughput and the harvested energy.
The simultaneous wireless information and power transfer (SWIPT) technique is regarded as a promising approach to enhance performance of wireless networks with limited energy supply. However, due to the broadcast nature of wireless radio, the energy receiver may act as a potential eavesdropper to eavesdrop the information sent to the information receiver. To address this issue, in this paper, we propose an optimization framework of the target secrecy rate and the power allocation ratio based on the secrecy outage probability and the effective secrecy throughput in the SWIPT system over fading wiretap channel. Moreover, we derive the closed-form expression of the secrecy outage probability and the effective secrecy throughput for two secrecy transmission modes. Furthermore, we formulate the effective secrecy throughput maximization problem under the reliability constraint in the on-off and adaptive transmission modes and provide the closed-form optimal solutions of the power allocation ratio and the target secrecy rate. Finally, we provide numerical results that give an insight into the effect of various system parameters on the secrecy outage probability and the effective secrecy throughput, such as the target secrecy rate, the power allocation ratio, and average gains of the main channel and the eavesdropper channel.
Simultaneous wireless information and power transfer (SWIPT) has recently drawn significant interests for its dual use of radio signals to provide wireless data and energy access at the same time. However, a challenging secrecy communication problem arises in the SWIPT system since the messages sent to information receivers (IRs) may be eavesdropped by energy receivers (ERs), which are presumed to receive energy from the same signals broadcast by the transmitter. To tackle this problem, we propose in this paper an artificial noise (AN) aided transmission scheme to facilitate the secrecy information transmission to IRs and yet meet the energy harvesting requirement for ERs, under the assumption that the AN can be cancelled at IRs but not at ERs. Specifically, the proposed scheme splits the power at the transmitter into two parts, to send the confidential message to the IR and an AN to interfere with the ER against eavesdropping, respectively. Under a simplified three-node wiretap channel setup, the transmit power allocations and power splitting ratios over fading channels are jointly optimized to maximize the average secrecy information rate for the IR subject to a combination of average and peak power constraints at the transmitter as well as an average energy harvesting constraint at the ER. The formulated problem is shown to be non-convex, for which we propose an efficient algorithm by iteratively optimizing the transmit power allocations and power splitting ratios over fading channels. Finally, the performance of the proposed scheme is evaluated by simulations and compared against other heuristic schemes in terms of achievable (secrecy) rate-energy trade-off.
Simultaneous wireless information and power transfer (SWIPT) has recently drawn significant interest for its dual use of radio signals to provide wireless data and energy access at the same time. However, a challenging secrecy communication issue arises as the messages sent to the information receivers (IRs) may be eavesdropped upon by energy receivers (ERs), which are presumed to harvest energy only from received signals. To tackle this problem, we propose in this paper an artificial-noise (AN)-aided transmission scheme to facilitate the secrecy information transmission to IRs and, yet, meet the energy harvesting requirement for ERs, under the assumption that the AN can be canceled at IRs but not at ERs. Specifically, the proposed scheme splits the transmit power into two parts: to send the confidential message to the IR and an AN to interfere with the ER, respectively. Under a simplified three-node wiretap channel setup, the transmit power allocations and power splitting ratios over fading channels are jointly optimized to minimize the outage probability for delay-limited secrecy information transmission or to maximize the average rate for no-delay-limited secrecy information transmission, subject to a combination of average and peak power constraints (APC and PPC) at the transmitter (Tx) and an average energy harvesting constraint at the ER. Both the secrecy outage probability minimization and average rate maximization problems are shown to be nonconvex, and for each, we propose the optimal solution based on the dual decomposition and the suboptimal solution based on the alternating optimization. Furthermore, two benchmark schemes are introduced for comparison where the AN is not used at the Tx and where the AN is used but cannot be canceled by the IR, respectively. Finally, the performances of proposed schemes are evaluated by simulations in terms of various tradeoffs for wireless (secrecy) information versus energy transmissions.
Simultaneous wireless information and power transfer (SWIPT) has drawn significant research interest in recent years.In this paper, we investigate the information theoretic secrecy of a SWIPT system under Weibull fading channel.To be specific, we analyze the information security in the presence of an energy harvesting and information decoding eavesdropper.All links are subjected to Weibull fading which is more complex than traditional Rayleigh fading.Moreover, we derive closed-form expressions for the probability of strictly positive secrecy capacity and the ergodic secrecy capacity.We evaluate the effect of Weibull shape parameter and power splitting factor on the secrecy performance of SWIPT system.Numerical and simulation results are provided to demonstrate that our findings are instantly applicable on the design of wireless power networks.
In this paper, we consider a multiuser multiple-input multiple-output (MIMO) downlink communication system with simultaneous wireless information and power transfer (SWIPT). In particular, we focus on a realistic and efficient multi-receiver multi-eavesdropper MIMO SWIPT system, in which the channel state information (CSI) of each legitimate receiver and energy receiver (i.e., potential eavesdropper) is partially known to the transmitter. Based on this, we propose a robust artificial noise (AN)-aided secure transmission scheme for the system, where the channel uncertainties are modeled by the worst-case model. In the proposed scheme, we aim to maximize the worst-case achievable secrecy rate under the transmit power constraint and the energy harvesting (EH) constraint, by jointly optimizing the transmit precoding matrix and the AN covariance matrix. We utilize the S-Procedure and Taylor series approximation to transform the non-convex problem. Then, we apply the interior point method to tackle the transformed convex problem, obtaining the approximate optimal matrices and the corresponding maximum worst-case secrecy rate. Simulation results show that our proposed scheme achieves significant performance improvements in terms of convergence and the worst-case achievable secrecy rate.
In this paper, a multiple-input single-output (MISO) simultaneous wireless information and power transfer (SWIPT) system, including one base station (BS) equipped with multiple antennas, one desired single-antenna information receiver (IR), and N (N > 1) single-antenna energy-harvesting receivers (ERs) is considered. Assuming that the information signal to the desired IR may be eavesdropped by ERs if ERs are malicious, we investigate the secrecy performance of the target MISO SWIPT system when imperfect channel state information (CSI) is available and adopted for transmit antenna selection at the BS. Considering that each eavesdropping link experiences independent but not necessarily identically distributed Rayleigh fading, the closed-form expressions for the exact and the asymptotic secrecy outage probability, and the average secrecy capacity are derived and verified by simulations. Furthermore, the optimal power splitting factor is derived for each ER to realize the tradeoff between the energy harvesting and the information eavesdropping. Our results reveal the impact of the imperfect CSI on the secrecy performance of MISO SWIPT systems in the presence of multiple wiretap channels.