In this paper, we propose a self-interference assisted cooperative jamming scheme to guarantee the security of wireless communication. Different from the traditional cooperative jamming schemes where artificial noise is designed in one phase (or one time slot), we design artificial noise in multiple phases. Moreover, we innovatively introduce carefully designed self-interference in the transmitted signals, which not only guarantees transmission efficiency, but also further enhances security. We first analyze the number of eavesdropping antennas on the security performance and then obtain the secrecy rate. Finally, simulation results corroborate our theoretical analysis.
In this paper, we propose a self-interference assisted cooperative jamming scheme to guarantee the security of wireless communication. Different from the traditional cooperative jamming schemes where artificial noise is designed in one phase (or one time slot), we design artificial noise in multiple phases. Moreover, we innovatively introduce carefully designed self-interference in the transmitted signals, which not only guarantees transmission efficiency, but also further enhances security. We first analyze the number of eavesdropping antennas on the security performance and then obtain the secrecy rate. Finally, simulation results corroborate our theoretical analysis.
This paper investigates cooperative security in wireless networks, where a source (Alice) intends to transmit a confidential message to a legitimate destination (Bob), with the help of a cooperative jammer (Charlie), coexisting with multiple passive eavesdroppers (Eves). In particular, by assuming knowledge of Bob's perfect channel state information (CSI) but only Eves’ statistical CSIs, secrecy beamforming with artificial noise (AN) is utilized for secure transmission, and cooperative jamming (CJ) is explored to further enhance secrecy. We first derive an accurate closed-form expression for the secrecy outage probability (SOP), and establish the condition under which positive secrecy rate is achievable. Then, we provide a secure transmit design for maximizing the SOP constrained secrecy rate. Moreover, based on a strict mathematical analysis, we characterize the impact of the main channel quality and the number of Eves on transmit design and secrecy performance. Specifically, optimal power allocation ratio between the information-bearing signal and the AN signal increases as the main channel quality improves, and decreases with the number of Eves. Numerical results confirm that our design achieves performance improvement in terms of both secrecy rate and secure energy efficiency, as compared to the approach without CJ.
In this paper, we propose a novel scheme of grouping cooperative jamming(CJ) for secure communication. During the data transmission, the source broadcasts its information signal, all the helpers simultaneously transmit common artificial noise(AN) to interfere the eavesdropper for tradition CJ. In our scheme, all the helpers are divided to different groups which transmit independent artificial noises to the potential eavesdropper. The zero-forcing beamfomer is selected to cancel the AN out at the destination. The tradition CJ scheme can not completely consume the total power budget, while the grouping scheme is based on the instantaneously channel gain which can make best of the total power per group. The simulations show that our propose scheme based on minimum distance achieves the highest secrecy rate and the power actual consumed approaches to the total power budget. Additionally, we propose a fixed grouping scheme based on the second-order statistics of the channel gain which can be easily implemented. Furthermore, we consider the case that the eavesdropper has knowledge of the artificial noise. The tradition CJ does not work in such case, while our scheme works well even only one group keeps its AN secret. The analytical results and simulations show our scheme achieves better performance than the tradition CJ.
This paper investigates the secure transmission in multiple access wiretap channels, where multiple legitimate users transmit private information to an intended receiver in the presence of multiple eavesdroppers. In order to improve security, we propose a novel cooperative jamming scheme, in which users do not share channel state information (CSI) but the legitimate channels will not be degraded by the artificial noise. The basic idea is to make each user exploit its own CSI in two slots to design artificial noise, so that the intended receiver can eliminate all the artificial noise but the eavesdroppers cannot. In this process, the interference between users plays a key role to achieve security, because it guarantees that the artificial noise from different users helps each other. We consider the non-collusion and collusion of eavesdroppers and analyze the secrecy performance for both scenarios. We adopt the secrecy sum-rate as the main metric, and show that positive secrecy sum-rate can be achieved by using the proposed scheme. Especially, we observe that when eavesdroppers collude and their additive white Gaussian noise (AWGN) close to zero, the number of users must not be less than twice the number of eavesdroppers to ensure positive secrecy sum-rate. Finally, simulation results are provided to corroborate our theoretical findings.
Wireless communication is vulnerable to deep fading and eavesdropping, especially in long-distance double-hop scenarios. To address these issues, this paper proposes the movable antenna (MA-assisted secure transmission scheme. This scheme is designed for a cooperative wireless communication system in the presence of multiple single-antenna eavesdroppers. Our objective is to maximize the achievable secrecy rate, by jointly optimizing the transmit beamforming and antenna positions vectors. To solve the highly non-convex problem due to the strongly coupled variables, the alternating optimization and projected gradient ascent (PGA) methods are designed to the joint update of MA position and beamforming. Furthermore, an artificial noise (AN) interference signal is introduced. Specifically, the legitimate link actively transmits jamming noise to eavesdroppers during signal transmission, thereby enhancing the channel capacity of the secure communication system. Finally, the simulation results show that the proposed MA-assisted secure transmission for the cooperative wireless communication system significantly outperforms conventional fixed-position antenna (FPA)-assisted systems by up to 70% and existing benchmarks in terms of secrecy rate.
In this paper, we investigate cooperative security in wireless networks, where a source (Alice) intends to transmit a confidential message to a legitimate destination (Bob), with the help of a cooperative node (Charlie), in the presence of multiple independent eavesdroppers (Eves). In particular, cooperative jamming (CJ) is explored to enhance secure communication between Alice and Bob. We provide a transmit design to maximize the secrecy rate, subject to a secrecy outage probability (SOP) constraint. Specifically, we establish a condition under which positive secrecy rate can be guaranteed. In addition to secrecy rate performance, we also pay attention to the secure energy efficiency, defined as the ratio of secrecy rate to total power consumption. Numerical results validate the effectiveness and energy efficiency of our proposed CJ scheme.
Due to the openness of wireless communication, information transmitted in the multiple access channel is vulnerable to eavesdropping by illegitimate users. Classic artificial noise-assisted schemes can improve security but are not suitable for power-constrained users. To address this problem, we propose a cross-time interference injection scheme in this paper, which improves security by introducing cross-time self-interference and inter-user interference, and does not require artificial noise. The proposed scheme exploits the properties of the Hadamard matrix and the wireless channels, so that the eavesdropping channel suffers from stronger interference than the legitimate channel. We analyze the security performance when both the legitimate receiver and the eavesdropper exploit the successive interference cancellation (SIC) scheme, including the secrecy sum rate, the secrecy capacity, and the secrecy outage probability. We further investigate the effect of the number of eavesdropper’s antennas, the number of legitimate users, and the number of time slots used by the scheme on the security performance, and obtain the corresponding relationship between these parameters when achieving a positive secrecy rate. Finally, simulation results corroborate our theoretical analysis.