Jamming Interference Research Articles

Jamming Suppression in Massive MIMO Systems

In this brief, we propose a framework for protecting the uplink transmission of a massive multiple-input multiple-output (mMIMO) system from a jamming attack. Our framework includes a novel minimum mean-squared error-based jamming suppression (MMSE-JS) estimator for channel training and a linear zero-forcing jamming suppression (ZFJS) detector for uplink combining. The MMSE-JS exploits some intentionally unused pilots to reduce the pilot contamination caused by the jammer. The ZFJS suppresses the jamming interference during the detection of the legitimate users’ data symbols. The proposed framework is implementable, since the complexities of computing the MMSE-JS and the ZFJS are linear (not exponential) with respect to the number of antennas at the base station and can be fabricated using 28-nm fully depleted silicon on insulator technology and for the mMIMO systems. Our analysis shows that the jammer cannot dramatically affect the performance of an mMIMO system equipped with the combination of MMSE-JS and ZFJS. Numerical results confirm our analysis.

Mitigating Jamming Attacks Using Energy Harvesting

The use of energy harvesting as a counter-jamming measure is investigated on the premise that part of the harmful interference can be harvested to increase the transmit power. We formulate the strategic interaction between a pair of legitimate nodes and a malicious jammer as a zero-sum game. Our analysis demonstrates that the legitimate nodes are able to neutralize the jammer. However, this policy is not necessarily a Nash equilibrium and hence is sub-optimal. Instead, harvesting the jamming interference can lead to relative gains of up to 95%, on average, in terms of Shannon capacity, when the jamming interference is high.

High-Resolution Radar Imaging in Complex Environments Based on Bayesian Learning With Mixture Models

We address the problem of high-resolution radar imaging in complex environments in a Bayesian framework. We perform model order selection and sparse weights estimation via the maximum a posterior-expectation maximization technique in a statistical model, where the noise obeys Gaussian mixture distribution; and the weights are governed by the sparsity-promoting Gamma-Gaussian hierarchical prior. The proposed method has closed-form solution and can be implemented efficiently by matrix operation. Experiments has shown that accounting for the noise with Gaussian mixture model instead of single Gaussian greatly improves the performance, and the proposed method provides an effective way of high-resolution radar imaging in complex environments such as barrage jamming and micro-Doppler interference.

Anti-Jamming Technology of SAR Seeker for Forward Squint of Aircaft

The SAR seeker has the capability of detecting all day long and all-weather. The imaging guidance of SAR can revise the error of inertial navigation, greatly improved the precision of the aircraft. However, the SAR seeker is vulnerable to interference from the other side, which affects imaging and guidance capability. In this paper, the basic principle, model and jamming effect of common noise, FM jamming and pulse jamming are given on the basis of introducing the working principle of SAR seeker. On this basis, this paper focuses on the anti-noise and anti-pulse jamming technology and interference principle of the SAR seeker with forward squint. After analysis, the anti-jamming principle is feasible, and it has the engineering application ability, and can be applied to the aircraft. In addition, from the point of view of the overall design of aircraft, some anti-jamming ideas of SAR seeker are given.

METHODS OF JAMMING INTERFERENCE

The article investigates the problem of providing high noise immunity radar under the influence of passive and intentional interference. The purpose of radio operation of the radar is to create conditions that would impede the operation of systems and minimize its effectiveness. The main method of radio transmission is still creating (staging) interference. Modern radar systems must solve the tasks in terms of electronic suppression using, including intentional interference and under severe time constraints. It is shown that the most effective way to improve the noise immunity of radar systems designed to operate in multipoint space, including non-stationary, interference is adaptive space-time processing of the received signals, based on the angular selection of targets, due to the formation of zeros in the directional diagram in the direction of interference sources. This problem is solved by determining the accuracy of the direction finding of interference sources and is achieved by the joint operation of the antenna array and multi-channel signal processing devices, namely the separation of interference signals on different receiving channels.

Interference-Aware Cooperative Anti-Jamming Distributed Channel Selection in UAV Communication Networks

This paper investigates the cooperative anti-jamming distributed channel selection problem in UAV communication networks. Considering the existence of malicious jamming and co-channel interference, we design an interference-aware cooperative anti-jamming scheme for the purpose of maximizing users’ utilities. Moreover, the channel switching cost and cooperation cost are introduced, which have a great impact on users’ utilities. Users in the UAV group sense the co-channel interference signal energy to judge whether they are influenced by co-channel interference. When the received co-channel interference signal energy is lower than the co-channel interference threshold, users conduct channel selection strategies independently. Otherwise, users cooperate with each other and take joint actions with a cooperative anti-jamming pattern under the impact of co-channel interference. Aiming at the independent anti-jamming channel selection problem under no co-channel interference, a Markov decision process framework is introduced, whereas for the cooperative anti-jamming channel selection case under the influence of co-channel mutual interference, a Markov game framework is employed. Furthermore, motivated by Q-learning with a “cooperation-decision-feedback-adjustment” idea, we design an interference-aware cooperative anti-jamming distributed channel selection algorithm (ICADCSA) to obtain the optimal anti-jamming channel strategies for users in a distributed way. In addition, a discussion on the quick decision for UAVs is conducted. Finally, simulation results show that the proposed algorithm converges to a stable solution with which the UAV group can avoid malicious jamming, as well as co-channel interference effectively and can realize a quick decision in high mobility UAV communication networks.

A Suppression Method against Spoofing Jamming based on Multipath Fading Detection

Today’s interference methods to the receiver include human jamming and non-human interference, and the human one can be divided into two types — suppressing jamming and spoofing jamming. In the spoofing jamming, the jamming source transmits or generates interference signal, trapping the receiver into a wrong location and time estimation of signals from receiving the real signal. Due to its strong similarity to the real one, the interference signal is difficult to be detected and suppressed by the receiver. Thanks to the similarity between spoofing jamming signal and multipath signal, the thesis aims to improve and optimize the WRELAX algorithm — by detecting and identifying signals after WRELAX algorithm according to the multipath fading, we can, finally, separate the spoofing jamming signal and real signal.

Application of Kaizen Concept with 8 Steps PDCA to Reduce in Line Defect at Pasting Process: A Case Study in Automotive Battery

Nowadays in very tight competition age, minimization of defect rate is targeted at all manufacturing production lines including in the process of automotive battery production. The purpose of this study was to reduce the dominant defect rate in the pasting process with Kaizen approach through 8 PDCA cycles. Kaizen implementation involves all parties in the company both management and employees in order to obtain optimal results. The eight cycles performed on Kaizen implementation are (i) Determination of theme, (ii) Targeting, (iii) Analysis of current conditions and problem-causing analysis, (iv) Root cause analysis of the problem, (v) Improvement plan, (vi) Implementation of the improvement, (vii) Evaluate the results, (viii) Standardization. Before Kaizen applied defect rate in the production process automotive batteries of 2.47% with the largest type of defect is plate scrap on the pasting process with a ratio of 2.45%. Kaizen implementation through 8 PDCA cycles implemented during 6 months managed to lower the defect rate to 1.52% or 0.08% better than the target set by the company of 1.60%. Improvements made due to jamming plate interference contributed to a 38 percent reduction in scrap plate in the pasting process.

The Effect of Time-Varying Jamming Interference on Networked Stabilization

The effect of jamming attacks on the networked control of a linear discrete-time dynamical system is investigated. In this networked control system, a wireless communication channel is used for the transmission of the control input packets from the controller to the plant. The probability of transmission failures on this channel depends on the power of the interference signals emitted by the jamming attacker. We explore the case where the attacker's interference power is time-varying but bounded in average. We obtain almost sure asymptotic stability conditions for the networked control system. In our stability analysis, we utilize nondecreasing and concave functions of the attacker's interference power that upper-bound the transmission failure probability. We also obtain upper and lower bounds on the probability of the state being outside a given level set at a given time. Finally, we present numerical examples to demonstrate the efficacy of our results under various scenarios.

MIMO-OFDM Energy Efficient Cognitive System with Intelligent Anti-jam Capability

Today's wireless communication systems are highly susceptible to malicious jamming attacks and interference signals. These attacks are sent via communication link at the same frequency as the inten...

A hierarchical learning approach to anti-jamming channel selection strategies

This paper investigates the channel selection problem for anti-jamming defense in an adversarial environment. In our work, we simultaneously consider malicious jamming and co-channel interference among users, and formulate this anti-jamming defense problem as a Stackelberg game with one leader and multiple followers. Specifically, the users and jammer independently and selfishly select their respective optimal strategies and obtain the optimal channels based on their own utilities. To derive the Stackelberg Equilibrium, a hierarchical learning framework is formulated, and a hierarchical learning algorithm (HLA) is proposed. In addition, the convergence performance of the proposed HLA algorithm is analyzed. Finally, we present simulation results to validate the effectiveness of the proposed algorithm.

Antijamming Schemes for Interference-Alignment-Based Wireless Networks

Interference alignment (IA) is a promising technique for interference management in wireless networks. On the other hand, jamming is a potential threat to wireless communications, which can degrade the performance of IA-based networks severely. Although some excellent work has been done on IA and antijamming, these two important aspects have traditionally been addressed separately in most previous work. In this paper, we study the antijamming issues and propose two antijamming schemes for IA-based networks. In the first scheme, the jamming signal and interferences are aligned into the same subspace at each receiver, and thus, can be perfectly eliminated together. When the requirement of perfect alignment can be relaxed, the second scheme is proposed to further improve the antijamming performance by maximizing the received signal-to-interference-plus-noise ratio (SINR). We derive the proper and feasibility conditions of the proposed two schemes. Simulation results are presented to show the effectiveness of the proposed schemes in mitigating jamming signals in IA-based wireless networks.

Research status and prospect of GNSS anti-spoofing technology}{Research status and prospect of GNSS anti-spoofing technology

With the increasing complexity of the electromagnetic environment and the increasing intensity of military confrontations, the potential security exposure in applications of satellite navigation has become a serious concern. Traditional GNSS anti-interference technology generally focuses on eliminating the jamming interference, while providing comparatively less attention to the elimination of spoofing interference. However, the potential risk induced by spoofing interference is no less than that caused by jamming interference. This paper first gives a broad overview of the research background on anti-spoofing technology, including the concept, theory, application cases, etc. Then it concludes and summarizes the research status of GNSS anti-spoofing technology in depth. Finally, it expounds emphatically some viewpoints on the prospect of GNSS anti-spoofing technology.

Securing cognitive radio with a combined approach of beamforming and cooperative jamming

The authors consider secret communication through a relay-assisted cognitive interference channel in which primary and secondary base stations (SBSs), respectively, communicate with the primary and secondary receivers (PU-Rx and SU-Rx) in the presence of multiple eavesdroppers. An SBS is allowed to transmit simultaneously with the primary base station (PBS). They propose three cooperative jamming (CJ) schemes based on the available channel state information at the base stations and the relay. The proposed CJ schemes are designed to create additional interference in the direction of eavesdroppers without creating any interference to the PU-Rx and the SU-Rx. A combined approach of beamforming and zero-forcing precoding is developed at the PBS, the SBS and the relay to cancel out jamming interference at the PU-Rx and the SU-Rx. The secrecy rate of SU-Rx is calculated with the constraint of maintaining interference temperature at the PU-Rx under a certain threshold. Compared with the direct transmission schemes that are available in the literature, the authors’ results show that the approach which combined beamforming and CJ significantly improves the secrecy rate of the cognitive interference channel.

CDMA System Design and Capacity Analysis Under Disguised Jamming

This paper considers robust code division multiple access (CDMA) system design and capacity analysis under disguised jamming, where the jammer generates a fake signal using the same spreading code, constellation, and pulse shaping filter as that of the authorized signal. Unlike Gaussian jamming, which is destructive only when jamming is dominant, disguised jamming can be devastating even if the jamming power is comparable to the signal power. In this paper, first, we analyze the performance of the conventional CDMA under disguised jamming, and show that due to the symmetricity between the authorized signal and the jamming interference, the receiver cannot really distinguish the authorized signal from jamming, leading to complete communication failure. Second, we propose to combat disguised jamming using secure scrambling. Instead of using conventional scrambling codes, we apply advanced encryption standard to generate the security-enhanced scrambling codes. Theoretical analysis based on the arbitrarily varying channel model shows that the capacity of conventional CDMA without secure scrambling under disguised jamming is actually zero; however, secure scrambling can break the symmetricity between the authorized signal and the jamming interference, and hence ensures positive channel capacity under disguised jamming. Numerical examples are provided to demonstrate the effectiveness of secure scrambling in combating disguised jamming.

Sector nulling in planar irregular sub‐arrayed sparse array antennas

This study concerns wide angular sector (higher order) null synthesis in planar irregular sparse antenna arrays when aperture distributed sub-arrays are used to reduce the computational load. A hybrid optimisation tool has been used to find array element excitations to achieve as low as possible sector nulls for the desired sector width. Performance comparisons have been made for three sub-array configurations based on the obtained numerical results. Various interference jamming scenarios have been considered including single and dual sectors for single-dimensional ( θ ) (1D) and two-dimensional ( θ , ϕ) (2D) nulls. The proposed optimisation scheme has shown to be successful for the synthesis of 1D and 2D sector nulls with depths as low as −100 dB for the given configuration with reduced computational time when compared with the full array. The comparison of achieved null depths for different sub-array sizes and convergence time has also been presented and discussed.

Exploiting Subcarrier Agility to Alleviate Active Jamming Attacks in Wireless Networks

Malicious interference injection or jamming is one of the simplest ways to disrupt wireless communications. Prior approaches can alleviate jamming interference to a limited extent; they are especially vulnerable to a reactive jammer i.e., a jammer that injects noise upon sensing a legitimate transmission or wideband jamming. In this paper, we leverage the inherent features of OFDM (Orthogonal Frequency Division Multiplexing) to cope with such attacks. Specifically, via extensive experiments, we observe that the jamming signal experiences differing levels of fading across the composite sub-carriers in its transmission bandwidth. Thus, if the legitimate transmitter were to somehow exploit the relatively unaffected sub-carriers to transmit data to the receiver, it could achieve reasonable throughputs, even in the presence of the active jammer. We design and implement JIMS , a Jamming Interference Mitigation Scheme that exploits the above characteristic by overcoming key practical challenges. Via extensive testbed experiments and simulations we show that JIMS achieves a throughput restoration of up to 75 percent in the presence of an active jammer.

Secure Degrees of Freedom of <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula>-User Gaussian Interference Channels: A Unified View

We determine the exact sum secure degrees of freedom (d.o.f.) of the K-user Gaussian interference channel. We consider three different secrecy constraints: 1) K-user interference channel with one external eavesdropper (IC-EE); 2) K-user interference channel with confidential messages (IC-CM); and 3) K-user interference channel with confidential messages and one external eavesdropper (IC-CM-EE). We show that for all of these three cases, the exact sum secure d.o.f. is K(K - 1)/(2K - 1). We show converses for IC-EE and IC-CM, which imply a converse for IC-CM-EE. We show achievability for IC-CM-EE, which implies achievability for IC-EE and IC-CM. Our converse is based on developing a direct relationship between the differential entropies of the channel inputs and the rates of the users, and quantifying the effect of eavesdropping on the rates in terms of the differential entropies of the eavesdroppers' observations. Our achievability is based on structured signaling, structured cooperative jamming, channel prefixing, and asymptotic real interference alignment. While the traditional interference alignment provides some amount of secrecy by mixing unintended signals in a smaller subspace at every receiver, in order to attain the optimum sum secure d.o.f., we incorporate structured cooperative jamming into the achievable scheme, and intricately design the structure of all of the transmitted signals jointly.

Energy Harvesting for Two-Way OFDM Communications under Hostile Jamming

Hostile jamming can cause significant performance degradation in wireless communications, but it also provides an unexplored source of additional signal power. In this letter, we propose an energy-harvesting receiver for two-way orthogonal frequency division multiplexing (OFDM) systems under hostile jamming. More specifically, in the downlink, the receiver is designed to simultaneously process information and harvest energy from the received desired signal as well as the jamming interference through a power splitter. The harvested energy can then be used as an additional source of power to enhance the uplink transmission. We investigate the optimal power allocation and power splitting ratio to maximize the sum-rate of the uplink and downlink transmissions. To reduce the complexity, a suboptimal energy harvesting scheme with closed-form solution is proposed. We also obtain a lower bound on the sum-rate of the proposed scheme under strong full-band jamming.

Cooperative Jamming Aided Robust Secure Transmission for Wireless Information and Power Transfer in MISO Channels

Considering simultaneous wireless information and power transfer (SWIPT), we investigate cooperative-jamming (CJ) aided robust secure transmission design in multiple-input-single-output channels, where a cooperative jammer introduces jamming interferences and assists a source to supply wireless power for both an energy receiver and a legitimate destination. The destination employs a power splitting (PS) scheme to split the received signals for both information decoding and energy harvesting (EH). Compared with conventional transmission without SWIPT, the transmission with SWIPT should satisfy additional worst-case EH constraints. Furthermore, the PS scheme introduces an additional multiplicative optimization variable, i.e., the PS factor. Our objective is to maximize worst-case secrecy rate under transmit power constraints and worst-case EH constraints. We propose to decouple the problem into three optimization problems and employ alternating optimization algorithm to obtain the locally optimal solution. For the optimization of transmit covariance matrices and PS factor, we propose to employ the ${\cal S} $ -procedure and its extension to reformulate it as a convex semidefinite programming. It is shown through the simulation results that our proposed CJ aided robust secure transmission scheme outperforms the robust direct transmission scheme without CJ and the CJ aided non-robust scheme.