This paper investigates the secrecy coding analysis of encoded wiretap Full-Duplex transmission respected to various eavesdropper positions. To limit the effect of interference and self-jamming/jamming signals sending by the legitimate receiver and eavesdropper, a combination of joint iterative blind/semi-blind channel estimation, decoding algorithms and self-jamming techniques is used. In fact, these algorithms employ a feedback loop to estimate and reduce SI components while also estimating the propagation channel and decoding the messages. The results reveal that blind/semi-blind algorithms give a better solution than conventional without feedback algorithms by significantly reducing and giving smaller security gap. Furthermore, they are less sensitive to the eavesdropper's movement by maintaining security gap in an acceptable level. The results also indicate that the suggested algorithms have a capability to notably decrease the self-jamming power required at the authorized receiver to obtain the same security level. It shows a robustness in several factors such as security, reliability and power consumption, which is suitable for short-packet Internet of Things transmissions and green communications.
This paper investigates the secrecy coding analysis of encoded wiretap Full-Duplex transmission respected to various eavesdropper positions. To limit the effect of interference and self-jamming/jamming signals sending by the legitimate receiver and eavesdropper, a combination of joint iterative blind/semi-blind channel estimation, decoding algorithms and self-jamming techniques is used. In fact, these algorithms employ a feedback loop to estimate and reduce SI components while also estimating the propagation channel and decoding the messages. The results reveal that blind/semi-blind algorithms give a better solution than conventional without feedback algorithms by significantly reducing and giving smaller security gap. Furthermore, they are less sensitive to the eavesdropper's movement by maintaining security gap in an acceptable level. The results also indicate that the suggested algorithms have a capability to notably decrease the self-jamming power required at the authorized receiver to obtain the same security level. It shows a robustness in several factors such as security, reliability and power consumption, which is suitable for short-packet Internet of Things transmissions and green communications.
This paper studies the secrecy coding analysis achieved by the self-jamming technique in the presence of an eavesdropper by considering a short-packet Full-Duplex (FD) transmission developed based on iterative blind or semi-blind channel estimation and advanced decoding algorithms. Indeed, the legitimate receiver and eavesdropper can simultaneously receive the intended signal from the transmitter and broadcast a self-jamming or jamming signal to the others. Unlike other conventional techniques without feedback, the blind or semi-blind algorithm applied at the legitimate receiver can simultaneously estimate, firstly, the Self-Interference (SI) channel to cancel the SI component and, secondly, estimate the propagation channel, then decode the intended messages by using 5G Quasi-Cyclic Low-Density Parity Check (QC-LDPC) codes. Taking into account the passive eavesdropper case, the blind channel estimation with a feedback scheme is applied, where the temporary estimation of the intended channel and the decoded message are fed back to improve both the channel estimation and the decoding processes. Only the blind algorithm needs to be implemented in the case of a passive eavesdropper because it achieves sufficient performances and does not require adding pilot symbols as the semi-blind algorithm. In the case of an active eavesdropper, based on its robustness in the low region of the Signal-to-Noise Ratio (SNR), the semi-blind algorithm is considered by trading four pilot symbols and only requiring the feedback for channel estimation processes in order to overcome the increase in noise in the legitimate receiver. The results show that the blind or semi-blind algorithms outperform the conventional algorithm in terms of Mean Square Error (MSE), Bit Error Rate (BER) and security gap (Sg). In addition, it has been shown that the blind or semi-blind algorithms are less sensitive to high SI and self-jamming interference power levels imposed by secured FD transmission than the conventional algorithms without feedback.
In this paper, we investigate secure short packet transmission from a legitimate transmitter to a receiver in the presence of an active eavesdropper. The aim is to gain more insights into how an active eavesdropper affects the secrecy throughput of short packet communications. The eavesdropper is assumed to have full-duplex (FD) capability, which enables performing eavesdropping and jamming simultaneously. All the communication links in the wiretap channel are assumed to be Rayleigh fading. An approximation of the average achievable secrecy throughput is proposed to measure the security of the system. The proposed approximation is examined and analysed in two different topology scenarios, which are triangular and line topologies. Then, Monte-Carlo simulations are performed to get an understanding of how good the approximation is. The results show that the closed-form expressions have a good match with Monte-Carlo simulations. We also investigate the impact of the eavesdropper's distance to the legitimate nodes as well as the different jamming power levels. Furthermore, self-interference influence on the eavesdropper is discussed.
Full-duplex (FD) jamming transceivers recently have been shown to enhance the information security of wireless communication systems by simultaneously transmitting artificial noise (AN) while receiving information. In this paper, we investigate whether FD jamming can also improve the system's secrecy energy efficiency (SEE) in terms of securely communicated bits per Joule when considering the additional power used for jamming and self-interference (SI) cancellation. Moreover, the degrading effect of the residual SI is also taken into account. In this regard, we formulate a set of SEE maximization problems for a FD multiple-input-multiple-output multiple-antenna eavesdropper (MIMOME) wiretap channel, considering both cases where exact or statistical channel state information (CSI) is available. Due to the intractable problem structure, we propose iterative solutions in each case with a proven convergence to a stationary point. Numerical simulations indicate only a marginal SEE gain, through the utilization of FD jamming, for a wide range of system conditions. However, when SI can efficiently be mitigated, the observed gain is considerable for scenarios with a small distance between the FD node and the eavesdropper, a high signal-to-noise ratio (SNR), or for a bidirectional FD communication setup.
As many security solutions integrated with various technologies have been proposed against eavesdropping attacks, technical advances for adversaries can also pose a serious security threat. This paper considers a problem of smart eavesdropping attacks on multiple-input-multiple-output wiretap channels for a legitimate transceiver. We present a smart eavesdropper model and a cooperative jamming solution between transceivers that can control the jamming signal power to achieve the optimal secrecy performance. In particular, for practical applications, our proposed solution considers the residual self-interference from the full-duplex receiver and the limited cancellation capability of the smart eavesdropper. We derive the secrecy outage probability in general and smart eavesdropper cases, and show numerical results and secrecy regions for evaluation. As a result, our proposed solutions can improve the secrecy performance significantly by exploiting the full-duplex receiver and the cooperative jamming strategies with the sophisticated power control according to power expenditure.
In this work we study the secrecy energy efficiency (SEE) of a multiple-input-multiple-output multiple-antenna eavesdropper (MIMOME) wiretap channel, in terms of the securely communicated bits-per-Joule, where the legitimate receiver is equipped with full-duplex (FD) capability. In particular, we seek answer to the question: if and how the application of an FD jammer can enhance the system SEE, considering the additional power consumption used for jamming and self-interference cancellation, as well as the degrading effect of residual self-interference. In this regard, an SEE maximization problem is formulated. Due to the intractable problem structure, an iterative solution is provided with a guaranteed convergence to a local optimum. Moreover, the proposed solution is extended for a system with a bidirectional communication, where both legitimate nodes are equipped with FD capability. Numerical simulations indicate a marginal SEE gain, via the utilization of FD jamming, for a wide range of system conditions. However, the observed gain is significant for the scenarios with a small distance between the FD node and the eavesdropper, a high signal-to-noise ratio (SNR) condition or for a bidirectional FD communication setup, under the condition that the self-interference can be effectively and efficiently mitigated.
In this paper, we examine the use of a friendly full-duplex (FD) relay to increase the secrecy rate over a fading channel between the legitimate source and the destination in the presence of residual self-interference (SI) and eavesdropper. In particular, we consider two different protocols based on the FD capability of relay: 1) FD transmission (FDT), in which the FD-Relay receives and sends data concurrently; 2) FD-Relay with jamming (FDJ), where first, the FD-Relay simultaneously receives data and sends jamming to the eavesdropper; then, it forwards the data, while the source jams the eavesdropper. We first develop the secrecy rate expressions for half-duplex transmission (HDT), half-duplex with jamming (HDJ), FDT, and FDJ relaying protocols, and then use them to derive their performance properties in terms of the channel gains between nodes, eavesdropper types, and more importantly, the SI level in FD-Relay. We further investigate the non-convex power allocation problems for the developed FDT and FDJ to maximize the secrecy rate under the power constraints. In particular, we develop an efficient iterative algorithm based on the difference-of-two-concave-functions programming. Analytical and simulation results show the strong influence of SI level on the achieved secrecy rate of the FDT and the FDJ. For sufficiently low SI, FDT achieves a much higher secrecy rate than FDJ, HDJ, and HDT. However, for higher SI, FDJ becomes more effective in enhancing the achieved secrecy rate. The results also indicate that adaptive power allocation can significantly improve the performance and confirm that the proposed FDT and FDJ outperform the HDT and the HDJ.