Full-duplex Jamming Research Articles

A new oversampling-based full-duplex radar jamming method with a single antenna

With the fast development of jamming technology, strong coherent jamming based on digital radio frequency memory (DRFM) technology poses serious threats to radar detection capabilities due to their flexibility and deception characteristics. However, the extremely high isolation between transmitter and receiver is difficult to implement in practice, and jammers typically operate in a transmit/receive time-sharing mode. Consequently, the duty cycle of jamming signal received by radar is less than 100% in the time domain, enabling the radar systems to detect targets amidst jamming. To generate a full duty cycle jamming signal, a new oversampling-based full-duplex DRFM jamming generation method is proposed in the transmit/receive time-sharing mode. This method requires that the intercepting width of jammer must be less than the reciprocal of value which is the product of forwarding times incremented by one and the radar signal bandwidth. Therefore, the jammer first intercepts extremely short segments from the radar signal using oversampling, with lengths measured in nanoseconds. Then, the jammer rapidly re-modulates and re-transmits the intercepted signal segments within the corresponding interception period. The jamming signal is filtered by the radar receiver. Then, the spectrum of the signal only contains the complete fundamental component, and the pulse width of the signal matches that of the transmitted signal, achieving a duty cycle of 100% and realizing the full-duplex jamming effect. In addition, the frequency modulation technique is utilized to generate dense false targets corresponding to the transmitted signal, thereby improving jamming efficiency. This paper elucidates the generation mechanism and ramifications of the jamming signal through rigorous signal analysis, delineating the relationship between intercepting length and full-duplex radar jamming generation across various DRFM jamming styles. Finally, the efficacy of full-duplex jamming is substantiated through theoretical analysis and simulation.

AN‐aided full‐duplex secure transmissions under imperfect self‐interference cancellation

SummaryThis paper considers a full‐duplex (FD) secure transmission scheme with aid of the artificial noise deployed at both transmitter and receiver under imperfect self‐interference cancellation. The expressions of secrecy and connection outage probabilities are derived, and hence, the secrecy throughput of the proposed scheme is evaluated. The results show that the performance of the proposed FD scheme outperforms that of conventional half‐duplex and FD receiver schemes in terms of the secrecy outage probability. In addition, the proposed FD scheme can achieve high secrecy throughput under various locations of the eavesdropper. Especially when the eavesdropper is located close to the transmitter, the secrecy throughput of the proposed FD scheme is nearly double that of the half‐duplex scheme with artificial noise injection while that of the scheme with FD jamming receiver goes to zero.

Constellation Design for Non-Coherent Fast-Forward Relays to Mitigate Full-Duplex Jamming Attacks

With potential applications to short-packet communication, we address communication of low-latency messages in fast-fading channels under the presence of a reactive jammer. Unlike a traditional jammer, we assume a full-duplex (FD) jammer capable of detecting pre-existing countermeasures and subsequently changing the target frequency band. To facilitate reliable communication amidst a strong adversary, we propose non-coherent fast-forward full-duplex relaying scheme wherein the victim uses a helper in its vicinity to fast-forward its messages to the base station, in addition to ensuring that the countermeasures are undetected by the FD adversary. Towards designing the constellations for the proposed scheme, we identify that existing non-coherent constellation for fast-fading channels are not applicable owing to the cooperative nature of the fast-forward scheme. As a result, we formulate an optimization problem of designing the non-coherent constellations at the victim and the helper such that the symbol-error-probability at the base station is minimized. We theoretically analyze the optimization problem and propose several strategies to compute near-optimal constellations based on the helper’s data-rate and fast-forwarding abilities. We show that the proposed constellations provide near-optimal error performance and help the victim evade jamming. Finally, we also prove the scheme’s efficacy in deceiving the countermeasure detectors at the jammer.

RF self-interference canceller prototype for 100-W full-duplex operation at 225–400 MHz

Military applications require more and different characteristics from in-band full-duplex radio technology than what the research prototypes developed for civil/commercial applications can offer. While the challenge of cancelling the strong transmit–receive coupling, i.e., self-interference (SI), in a full-duplex radio has been largely resolved at higher ultra high frequency (UHF) bands for low-power transmission, tactical communication and electronic warfare applications require major research efforts toward supporting lower military-relevant frequencies and significantly higher transmission power levels. In this paper, we present a prototype of a radio-frequency SI cancellation circuit for the lower UHF band at 225–400 MHz and transmit power of up to 100–200 W. The experimental results demonstrate that the canceller can suppress SI by 40–50 dB depending on the operation frequency within the band. It is targeted for the military application of simultaneous full-duplex jamming and interception of communications, where we can estimate that a 5-W signal-of-interest could be intercepted from 10 km away when simultaneously jamming with 100 W power.

Secrecy Performance for Full-Duplex Jamming-Aided Uplink NOMA System

Full duplex (FD) is one of the most attractive technologies in enhancing spectral efficiency for potentially doubling the system throughput. In this work, we employ FD jamming to improve the secrecy performance of an uplink non-orthogonal multiple access (NOMA) system at the presence of one eavesdropper. We first evaluate the individual secrecy performance in terms of effective secrecy throughput (EST), by deriving its closed-form expression. Valuable insights are provided into the impacts of transmit power, jamming power as well as the number of antennas. Asymptotic analyses concerning these three arguments show the secrecy performance is location-dependent only in the high regime of transmit power and approaches to the main capacity in the high regime of the other two arguments. A special case, beamforming FD jamming, is next studied such that <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> -fold power gain on jamming is available, in turn, improving the secrecy performance. Limited gains from high transmit and jamming power prompt us to further investigate two optimal power allocation problems: (1) optimal power allocation to minimize total power, subject to an overall secrecy performance requirement; (2) optimal power allocation to maximize overall secrecy performance, with constraint of total power. The solutions to these two optimization problems are given and demonstrated numerically with appropriate cases.

Multi-Antenna Covert Communication via Full-Duplex Jamming Against a Warden With Uncertain Locations

Covert communication can hide the information transmission process from the warden to prevent adversarial eavesdropping. However, it becomes challenging when the location of warden is uncertain. In this paper, we propose a covert communication scheme against a warden with uncertain locations, which maximizes the connectivity throughput between a multi-antenna transmitter and a full-duplex jamming receiver with the limit of covert outage probability (the probability of the transmission found by the warden). First, we analyze the monotonicity of the covert outage probability to obtain the optimal location for the warden. Then, under this worst situation, we optimize the transmission rate, the transmit power and the jamming power of covert communication to maximize the connection throughput. This problem is solved in two stages. First, we derive the transmit-to-jamming power ratio limit from the maximum allowed covert outage probability. With this constraint, the connection probability is maximized over the transmit-to-jamming power ratio for a fixed transmission rate. Since the connection probability and the transmission rate are coupled, the bisection method is applied to maximize the connectivity throughput via optimizing the transmission rate iteratively. Simulation results are presented to evaluate the effectiveness of the proposed scheme.

Analysis of SWIPT-Enabled Relay Networks with Full-Duplex Destination-Aided Jamming

Simultaneous wireless information and power transfer (SWIPT) is a major breakthrough in the field of low-power wireless information transmissions. In this paper, the secrecy performance of the SWIPT-enabled relay network with full-duplex destination-aided jamming is assessed, where both the power-splitting (PS) and time-switching (TS) schemes at the relay are considered with the linear and nonlinear energy harvesting models. The relay harvests energy from the confidential signal and artificial noise sent by the source and destination, respectively, and forwards the amplified signal to the destination, in the presence of an eavesdropper. The analytical closed-form expressions of the connection outage probability (COP), secrecy outage probability (SOP), and transmission outage probability (TOP) for PS- and TS-based schemes are derived, and the closed-form expression of the lower bound of ergodic secrecy capacity (ESC) is calculated. The asymptotic-form expressions of the COP, SOP, TOP, and ESC are further analyzed to capture the valuable information in the high SNR regime. Numerical results verify the correctness of analytical results, reveal the effects of the PS/TS ratio, and transmit the signal-to-noise ratio on secrecy performance.

Securing Wireless Transmissions With RIS-Receiver Coordination: Passive Beamforming and Active Jamming

In this correspondence, we investigate the physical layer security issue with the assistance of a reconfigurable intelligent surface (RIS). In particular, we consider the single-input and multiple-output transmissions in the presence of a multi-antenna eavesdropper, where the legitimate receiver actively performs full-duplex jamming to confuse the eavesdropper. Meanwhile, the passive beamforming of the RIS is coordinated with the legitimate reception and jamming for security enhancement, leading to the joint optimization of receive beamforming, active jamming, and passive beamforming. The problem is solved under a block coordinate descent framework, where the receive beamforming is obtained through generalized eigenvalue decomposition, and the active jamming and passive beamforming are solved based on semidefinite programming. Simulation results show the combined effect of jamming and reflection upon the secrecy rate, also demonstrated is the performance superiority of the proposed scheme as compared with the conventional approaches in terms of wireless security.

Joint Buffer-Aided Hybrid-Duplex Relay Selection and Power Allocation for Secure Cognitive Networks With Double Deep Q-Network

This paper applies the reinforcement learning in the joint relay selection and power allocation in the secure cognitive radio (CR) relay network, where the data buffers and full-duplex jamming are applied at the relay nodes. Two cases are considered: maximizing the throughput with the delay and secrecy constraints, and maximizing the secrecy rate with the delay constraint, respectively. In both cases, the optimization relies on the buffer states, the interference to/from the primary user, and the constraints on the delay and/or secrecy. This makes it mathematically intractable to apply the traditional optimization methods. In this paper, the double deep Q-network (DDQN) is used to solve the above two optimization problems. We also apply the a-priori information in the CR network to improve the DDQN learning convergence. Simulation results show that the proposed scheme outperforms the traditional algorithm significantly.

SDR Proof-of-Concept of Full-Duplex Jamming for Enhanced Physical Layer Security.

In order to secure wireless communications, we consider the usage of physical-layer security (PLS) mechanisms (i.e., coding for secrecy mechanisms) combined with self-interference generation. We present a prototype implementation of a scrambled coding for secrecy mechanisms with interference generation by the legitimate receiver and the cancellation of the effect of self-interference (SI). Regarding the SI cancellation, four state-of-the-art algorithms were considered: Least mean square (LMS), normalized least mean square (NLMS), recursive least squares (RLS) and QR decomposition recursive least squares (QRDRLS). The prototype implementation is performed in real-world software-defined radio (SDR) devices using GNU-Radio, showing that the LMS outperforms all other algorithms considered (NLMS, RLS and QRDRLS), being the best choice to use in this situation (SI cancellation). It was also shown that it is possible to secure communication using only noise generation by the legitimate receiver, though a variation of the packet loss rate (PLR) and the bit error rate (BER) gaps is observed when moving from the fairest to an advantageous or a disadvantageous scenario. Finally, when noise generation was combined with the adapted scrambled coding for secrecy with a hidden key scheme, a noteworthy security improvement was observed resulting in an increased BER for Eve with minor interference to Bob.

A Secure Multiuser Privacy Technique for Wireless IoT Networks Using Stochastic Privacy Optimization

With the exponential increase of interconnected communicating devices which make up the Internet of Things (IoT), securing the network transmission and the fifth generation (5G) systems which is the bedrock for IoT concept actualization is becoming more and more challenging. One of the major attacks which poses a great risk to data transmission is the eavesdropper (Eve) attack which occurs in both single input, single output (SISO), multiple input and multiple output (MIMO) systems. Thus, in this study, our focus is to establish a secured connection in a multiple-antenna transmission when the channel state information (CSI) of Eve is unknown to the network users. Our model comprises a secure wireless communication standard where Eve performs either optimal matched filtering (OMF) or a basic matched filtering (BMF) while the transmitting IoT node employs smart jamming strategy in order to compromise the activities of Eve. With respect to this and in attempt to realize maximum privacy, we examined the design of optimal jamming parameters. In the end, the numerical analysis of our investigation indicates that a substantial privacy advantage is achievable while utilizing only full-duplex jamming against using artificial noise from the transmitter only. However, a joint performance of both results shows a higher privacy improvement.

RIS-Aided Physical Layer Security With Full-Duplex Jamming in Underlay D2D Networks

This paper investigates the physical layer security and data transmission for the underlay device-to-device (D2D) networks, and considers a combination of the reconfigurable intelligent surface (RIS) and full-duplex (FD) jamming receiver for the robustness and security enhancements of the system. In the demonstrated spectrum sharing setup, the total power of the D2D networks is conceived to the transmitter and receiver to transmit a private message and emit the artificial noise (AN) signals. To prevent information leakage, a beamforming design is presented for a multi-antenna FD D2D receiver in order to suppress and inject the AN signals in the direction of legitimate users and eavesdropper, respectively. The statistical characterization of end-to-end RIS-assisted wireless channels is presented, and the achievable ergodic secrecy rate of the system is derived in novel approximate expressions. The numerical and simulation results confirm the accuracy and effectiveness of the proposed analytical framework. The results demonstrate an optimal selection of the D2D power allocations for different number of reflecting elements in terms of achievable ergodic secrecy rates of the system.

Secrecy Analysis for Full-Duplex Jamming-Aided Uplink NOMA System

Full duplex (FD) is one of the most attractive technologies in enhancing spectrum efficiency for potentially doubling the system throughput. In this work, we employ FD jamming to improve the secrecy performance of an uplink non-orthogonal multiple access (NOMA) system at the presence of one eavesdropper. We first characterize the individual secrecy performance in terms of effective secrecy throughput (EST), and derive its closed-form expression via secrecy outage probability (SOP). We then further investigate the problem of optimal power allocation to maximize overall secrecy performance. The solution to the optimization problem is figured out and demonstrated numerically with an appropriate case.

Power Splitting-Based SWIPT Systems With Full-Duplex Jamming

The simultaneous wireless information and power transfer (SWIPT) has recently attracted much attention since both information and energy are integrated within radio frequency signals, which is considered to be one of the most important technologies for future networks. However, security becomes one of the most critical issues in SWIPT networks due to its broadcasting features over wireless media and the transferring requirements for strong signal strength. To improve the security of SWIPT networks, in this paper, a SWIPT system enabled by full-duplex (FD) jamming is proposed, where an FD energy-limited receiver with the power splitting (PS) structure, powered by a transmitter, generates jamming signals. Both linear and nonlinear energy harvesting (EH) models are considered. To evaluate the secrecy throughput (ST) of the system, we derive the closed-form connection outage probability and secrecy outage probability for the proposed PS-based scheme in the delay-constrained transmission (DCT) mode. The ST is maximized by optimizing the PS ratio based on the asymptotic cases of the high signal-to-noise ratio as well as the perfect self-interference cancellation (SIC). Besides, the exact integral forms of the ergodic secrecy capacity and their closed-form lower bounds are presented for both the PS-based and the time switching (TS)-based schemes in the delay-tolerant transmission (DTT) mode. Simulation results suggest that the PS-based scheme outperforms the TS-based scheme for the DTT mode. For the DCT mode, the PS-based scheme can achieve better performance than the TS-based scheme only in low target communication rate, small PS/TS ratio, high transmit power, and weak path loss. Meanwhile, given a tolerable amount of SIC, the ST obtained in the linear EH model is higher than that achieved in the nonlinear EH model.

Enhanced Secrecy Performance of Multihop IoT Networks With Cooperative Hybrid-Duplex Jamming

As the number of connected devices is exponentially increasing, security in Internet of Things (IoT) networks presents a major challenge. Accordingly, in this work we investigate the secrecy performance of multihop IoT networks assuming that each node is equipped with only two antennas, and can operate in both Half-Duplex (HD) and Full-Duplex (FD) modes. Moreover, we propose an FD Cooperative Jamming (CJ) scheme to provide higher security against randomly located eavesdroppers, where each information symbol is protected with two jamming signals by its two neighbouring nodes, one of which is the FD receiver. We demonstrate that under a total power constraint, the proposed FD-CJ scheme significantly outperforms the conventional FD Single Jamming (FD-SJ) approach, where only the receiving node acts as a jammer, especially when the number of hops is larger than two. Moreover, when the Channel State Information (CSI) is available at the transmitter, and transmit beamforming is applied, our results demonstrate that at low Signal-to-Noise Ratio (SNR), higher secrecy performance is obtained if the receiving node operates in HD and allocates both antennas for data reception, leaving only a single jammer active; while at high SNR, a significant secrecy enhancement can be achieved with FD jamming. Our proposed FD-CJ scheme is found to demonstrate a great resilience over multihop networks, as only a marginal performance loss is experienced as the number of hops increases. For each case, an integral closed-form expression is derived for the secrecy outage probability, and verified by Monte Carlo simulations.

Full-Duplex Jamming and Interception Analysis of UAV-Based Intrusion Links

This letter addresses the evaluation of the performance of a full-duplex (FD) jammer and intercepting node, where the FD node attempts to disrupt the communication link of an intruding unmanned aerial vehicle (UAV). The FD node's performance is evaluated by deriving an analytical expression of the probability of successfully interrupting the communication link between the UAV node and its control source (CS). Moreover, the analysis takes into account the channel characteristics between the interacting nodes. Simulations were conducted to examine the dynamics of the proposed system model by varying different key parameters. The conducted simulations verify the accuracy of our derived expressions, and the results highlight the importance of having low residual self-interference power in order to successfully intercept the communication link between the UAV node and its control source.

Improving Physical Layer Security of Cellular Networks Using Full-Duplex Jamming Relay-Aided D2D Communications

This paper investigates the physical layer security and data transmission in cellular networks with inband underlay Device-to-Device (D2D) communications, where there is no direct link between D2D users. We propose to apply full-duplex (FD) transmission and dual antenna selection at the D2D relay node. The relay node can simultaneously act as a friendly jammer to improve the secrecy performance of the cellular network while enhancing the D2D communication data transmission. This is an appealing and practical scheme where spectrum sharing is beneficial for the D2D and cellular networks in terms of reliability enhancement and security provisioning, respectively. The practical scenario, where the eavesdropper is passive, is considered. The eavesdropper uses either selection combining or maximal ratio combining to combine the wiretapped signals of the cellular network. The secrecy performance of the cellular network is analyzed, and closed-form expressions for the secrecy outage probability and the probability of non-zero secrecy capacity are derived. We show that increasing the number of FD jamming antennas enhances the secrecy performance of the cellular network. A closed-form expression of the D2D outage probability is also provided. Simulation and numerical results are provided to verify the efficiency of the proposed scheme and to validate the accuracy of the derived expressions.

Secrecy Energy Efficiency of MIMOME Wiretap Channels With Full-Duplex Jamming

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.

Secrecy Analysis for Cooperative NOMA Networks With Multi-Antenna Full-Duplex Relay

In a downlink non-orthogonal multiple access (NOMA) system, the reliable transmission of cell-edge users cannot be guaranteed due to severe channel fading. On the other hand, the presence of eavesdroppers can severely threaten the secure transmission due to the open nature of wireless channel. Thus, a two-user NOMA system assisted by a multi-antenna decode-and-forward relay is considered in this paper, and a two-stage jamming scheme, full-duplex-jamming (FDJam), is proposed to ensure the secure transmission of NOMA users. In the FDJam scheme, using full-duplex, the relay transmits the jamming signal to the eavesdropper while receiving confidential messages in the first stage, and the base station generates the jamming signal in the second stage. Furthermore, we eliminate the self-interference and the jamming signal at the relay and the legitimate node, respectively, through relay beamforming. To measure the secrecy performance, analytical expressions for secrecy outage probability (SOP) are derived for both the cell-center and cell-edge users, and the asymptotic SOP analysis at high transmit power is presented as well. Moreover, two benchmark schemes, half-duplex-jamming and full-duplex-no-jamming, are also considered. Simulation results are presented to show the accuracy of the analytical expressions and the effectiveness of the proposed scheme.

Sum secrecy rate maximization for multi-carrier MIMOME systems with full-duplex jamming

In this work we study the sum secrecy rate maximization problem for a multi-carrier and multiple-input-multiple-output multiple-antenna eavesdropper (MIMOME) communication system. We consider the setup that the receiver is capable of full-duplex (FD) operation and simultaneously sends jamming signal to a potential eavesdropper. In particular, we intend to achieve a higher security level in the physical layer by simultaneously utilizing the spatial and frequency diversity of the FD-enabled system. In order to deal with the non-convex nature of the problem, we reformulate the problem as a separately convex program and propose an iterative algorithm. The iterative solution has a guaranteed convergence based on block coordinate descent method. Furthermore, for a simplified scenario where the transmitter is only equipped with a single antenna, the system is mitigated to a transmit power allocation problem. We obtain an optimal solution analytically with the assumption of a known jamming strategy. We also study an FD bidirectional secure communication system, where both transceivers are capable of FD operation. The numerical evaluations indicate the gain of an optimized jamming strategy for an FD multi-carrier system.