Noise Jamming Research Articles

A novel noise reduction algorithm and its application in failure information extraction of bearing

The performance of rolling bearing can directly affect the reliability of a rotating machine. Due to the influence of noise and irrelevant components, the fault information is rather weak in a bearing fault, which adds to the difficulty in judgment of bearing state and identification of fault types. To solve the problem of heterogeneous feature information caused by noise jamming in rolling bearing failure, difficulty in extracting fault feature, and misdiagnosis and misjudgment, the paper has proposed a denoising algorithm according to the covariance matrix of a Hankel matrix and information entropy (Hankel-Cov-IE). First, covariance matrix of a Hankel matrix of signals is constructed, and fault signals are preliminarily denoised based on denoising capacity of the covariance matrix and its nature of combining global and local features. To address the selection of sensitive fault components, information entropy (IE) is taken advantage of to screen out the vectors containing abundant feature information from the covariance matrix. The filtered feature vectors are reconstructed in the way of equal weight and faults of rolling bearing are identified with the spectrum of signals reconstructed. The presented algorithm is compared with different typical methods. The results indicate that the presented algorithm can reduce noise more effectively and achieve extraction of bearing failure features more comprehensively and correctly, with correct judgment of fault types. The presented algorithm can correctly extract the feature frequency of bearing fault and recognize the types of faults, and is insensitive to sensor sites, speeds, and failure types of bearings.

Band Correlation‐Based Multichannel Multiscale Convolution Network for Intelligent Interference Recognition

AbstractIn recent years, with the development and extensive application of wireless communication technology, the communication system should have stronger anti‐Jamming ability. Therefore, interference recognition is particularly important as a prerequisite for anti‐interference. However, the existing traditional and intelligent interference recognition algorithms have problems such as complicated feature extraction and low recognition accuracy under low interference‐to‐noise ratio. In order to solve the above problems, this paper introduces parallel multi‐channel multi‐scale convolution to improve the speed and accuracy of network recognition. In addition, combined with frequency band correlation and long‐short‐term memory network (LSTM), an innovative wireless communication interference identification model based on frequency band correlation is proposed, which uses LSTM to detect the frequency band correlation of interference signals and improve the accuracy of interference identification under low Jamming noise ratio (JNR). Experiments prove that the model proposed in this article has faster recognition speed and better generalization. The introduction of frequency band correlation increases the recognition accuracy to more than 99% with low JNR. Therefore, the model proposed in this paper is an effective and available model in complex electromagnetic environments. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Distributed Symmetric Turbo Coded OFDM Scheme Incorporated with STBC-MIMO Antennas for Coded-Cooperative Wireless Communication under Wideband Noise Jamming Environment

Distributed Symmetric Turbo Coded OFDM Scheme Incorporated with STBC-MIMO Antennas for Coded-Cooperative Wireless Communication under Wideband Noise Jamming Environment

Способ повышения помехоустойчивости радиолинии связи в условиях деструктивного воздействия преднамеренных помех

The evaluation of noise immunity of reception of DPSK signals in the mode of frequency hopping spread spectrum (FHSS) for unmanned aerial vehicle (UAV) command and control radio links under the influence of narrowband noise interference (partial-band noise jamming) is performed. It is shown that the noise immunity of data transmission for UAVs under conditions of destructive noise interference can be improved by applying the mode of intra-symbol FHSS with the implementation of an algorithm for weighted signal processing to receive these signals. By the method of mathematical modeling it is shown that the work in the mode of FHSS with switching off of channels strongly affected by intentional interference allows to provide a more significant increase in the noise immunity of data transmission for the UAV communication radio links.

Mitigating Jamming in FSO Cooperative Networks: A Buffer-Aided Relaying Approach

In this paper, we propose a buffer-aided relaying-based approach to counter the effects of jamming in free space optical (FSO) communication networks. An FSO cooperative system with a source node, a relay node, and a destination node is considered. The relay node consists of a finite-size buffer, and both relay and destination nodes are assumed to be affected by jamming. We use a Markov chain (MC) based approach to obtain the state transition matrix of the system, which is later used to evaluate the steady state probability of the proposed setup. A mixture of jamming and Gaussian noise is considered to evaluate the system’s performance. Novel expressions of the outage probability and average bit error rate of the considered FSO system are obtained. The system’s performance is then analyzed for different jamming powers and jamming probabilities. The proposed system is then compared with a non-buffer-aided (NBA) cooperative FSO system affected by a jammer; it is observed that the proposed buffer-aided FSO system significantly outperforms the NBA counterparts.

Analysis of Characteristics and Suppression Methods for Self-Defense Smart Noise Jamming

Self-defense smart noise jamming can automatically aim a signal frequency and obtain antenna gain and matching filtering processing gain, posing a huge threat to the normal performance of radar. In response to this situation, this article conducts an in-depth analysis of two typical smart noise jamming methods: noise convolution jamming methods and noise product jamming methods. The distribution characteristics of the two jamming methods in both time–frequency dimensions and their internal time–frequency relationships are analyzed. Based on this, a self-defense smart noise jamming suppression method based on pulse frequency stepping is proposed. This method obtains the true distance information of the target based on the phase difference caused by frequency stepping between adjacent pulses and uses this information to construct a filter to filter the radar echo, achieving jamming suppression. Simulation experiments have verified the effectiveness of this method.

Towards the Designing of Low-Latency SAGIN: Ground-to-UAV Communications over Interference Channel

We present a novel and first-of-its-kind information-theoretic framework for the key design consideration and implementation of a ground-to-unmanned Aerial Vehicle (UAV) (G2U) communication network with an aim to minimize end-to-end transmission delay in the presence of interference in Space-Air-Ground Integrated Networks (SAGIN). To characterize the transmission delay, we utilize Fano’s inequality and derive the tight upper bound for the capacity for the G2U uplink channel in the presence of interference, noise, and potential jamming. In addition, as a function of the location information of the UAV, a tight lower bound on the transmit power is obtained subject to the reliability constraint and the maximum delay threshold. Furthermore, a relay UAV in the dual-hop relay mode, with amplify-and-forward (AF) protocol, is considered, for which we jointly obtain the optimal positions of the relay and the receiver UAVs in the presence of interference, with straight-line, circular, and helical trajectories as UAV tracing. Interestingly, increasing the power gives a negligible gain in terms of delay minimization, though may greatly enhance the outage performance. Moreover, we prove that there exists an optimal height that minimizes the end-to-end transmission delay in the presence of interference. We show the interesting result of the delay analysis. In particular, it is shown that receiver location and the end-to-end signal-to-noise power ratio play a critical role in end-to-end latency. For instance, with the transmitter location fixed to (0, 0, 0) and the interferer location set to (0, 500 m, 0), the latency generally increases with increasing the receiver’s vertical height (z-axis). With the receiver’s horizontal coordinates, i.e., (xR, yR) set to (0, 0) reducing the receiver’s height from 200 m to 50 m decreases the delay latency (codeword length) by more than 30% for an interference-limited channel. Whereas, for an interference channel with a signal-to-noise power ratio equal to 30 dB, the latency decreases by approximately 2%. The proposed framework can be used in practice by a network controller as a system parameters selection criteria, where among a set of parameters, the parameters leading to the lowest transmission latency can be incorporated into the transmission. The based analysis further set the baseline assessment when applying Command and Control (C2) standards to mission-critical G2U and UAV-to-UAV (U2U) services.

Quantum Induced Coherence Light Detection and Ranging.

Quantum illumination has been proposed and demonstrated to improve the signal-to-noise ratio (SNR) in light detection and ranging (LiDAR). When relying on coincidence detection alone, such a quantum LiDAR is limited by the timing jitter of the detector and suffers from jamming noise. Inspired by the Zou-Wang-Mandel experiment, we design, construct, and validate a quantum induced coherence (QuIC) LiDAR which is inherently immune to ambient and jamming noises. In traditional LiDAR the direct detection of the reflected probe photons suffers from deteriorating SNR for increasing background noise. In QuIC LiDAR we circumvent this obstacle by only detecting the entangled reference photons, whose single-photon interference fringes are used to obtain the distance of the object, while the reflected probe photons are used to erase path information of the reference photons. In consequence, the noise accompanying the reflected probe light has no effect on the detected signal. We demonstrate such noise resilience with both LED and laser light to mimic the background and jamming noise. The proposed method paves a new way of battling noise in precise quantum electromagnetic sensing and ranging.

An Antijamming Method Based on Multichannel Singular Spectrum Analysis and Affinity Propagation for UWB Ranging Sensors

Ultra-wideband impulse radio system has received extensive attention due to their high resolution and poor interception possibility. But the specific electromagnetic threat posed by its complex work environment cannot be ignored. In all kinds of active jamming signals, smart noise jamming plays an important role in modern radar electronic warfare, and most traditional anti-jamming methods have less suppression effect. In this paper, the mechanism of smart noise jamming on the UWB ranging sensor is discussed first. On this basis, an anti-smart noise jamming method based on multichannel singular spectrum analysis and kurtosis characteristic is proposed. Experiments show that smart noise jamming is more threatening to the UWB system than other noise modulation jamming. And the improved algorithm proposed in this paper can suppress the jamming better. After the anti-jamming processing, the average detection probability can reach more than 95%. Meanwhile, the method is improved by adding the affinity propagation (AP) clustering algorithm to solve the underdetermined signal separation problem in the case of compound jamming. The advantage is that it does not have to estimate the number of signals first. Even if the SJR is -10 dB, the waveform similarity between the separation signal and the source signal can reach 0.7 or more.

Security-reliability tradeoff of MIMO TAS/SC networks using harvest-to-jam cooperative jamming methods with random jammer location

This paper evaluates outage probability (OP) and intercept probability (IP) of physical-layer security based MIMO networks adopting cooperative jamming (Coop-Jam). In the considered scenario, a multi-antenna source communicates with a multi-antenna destination employing transmit antenna selection (TAS)/ selection combining (SC), in presence of a multi-antenna eavesdropper using SC. One of jammers appearing near the destination is selected for generating jamming noises on the eavesdropper. Moreover, the destination supports the wireless energy for the chosen jammer, and cooperates with it to remove the jamming noises. We consider two jammer selection approaches, named RAND and SHORT. In RAND, the destination randomly selects the jammer, and in SHORT, the jammer, which is nearest to the destination, is chosen. We derive exact and asymptotic expressions of OP and IP over Rayleigh fading, and perform Monte-Carlo simulations to verify the correction of our derivation. The results present advantages of the proposed RAND and SHORT methods, as compared with the corresponding one without using Coop-Jam.

Modeling and Analysis of Thermal Covert Channel Attacks in Many-core Systems

In a many-core chip, thermal flux and thermal correlation among the cores can be explored to create a thermal covert channel (TCC). In this paper, we provide an analytical model to quickly determine the key TCC performance metrics, in terms of bit error rate (BER), signal to noise ratio (SNR), and channel capacity, without going through lengthy computer simulation and/or physical experiments that are normally needed in current TCC performance studies. According to our model, the TCC’s BER is proportional to the square root of the transmission frequency, which can be explored quantitatively to boost the TCC’s transmission efficiency by letting the TCC’s thermal signal be transmitted at a higher frequency. In addition, our proposed model also links the jamming noise and application of Dynamic Voltage Frequency Scaling (DVFS) to TCC’s BER performance, a feature that can be explored to design/optimize the countermeasures against the TCC attacks. The TCC performance predicted by the proposed theoretical model is found in a good agreement with that obtained from computer simulations, with an average error lower than 7%.

Micro-Stepping Motor for Instrument Panel Using PWM Drive Method

This study presents a pointer-driven controller for an instrument panel. The proposed pointer utilizes the permanent magnet (PM) stepping motor produced by the Japanese company NMB. This stepping motor is vibration-proof and tolerates noise jamming as well as wind and rain exposure. Moreover, it has no mechanical structures and is low cost. Most importantly, it features accurate positioning; therefore, it can be used to measure vehicle speed, engine speed, fuel capacity, and temperature. However, the PM stepping motor of the NMB pointer requires 10 degrees for each step, and this low resolution results in roll hesitation as its steps. The aim of the current paper was to solve the problems of the large angle size and low resolution associated with this stepping motor. Based on two-phase excitation, we propose driving the motor using pulse width modulation (PWM). Specifically, we divided each 10-degree step into 100 equal parts. In other words, every step is 0.1 degrees. The resolution of pointer rotation can be increased by 100-fold by using the approach proposed in this paper. When applied to vehicle (or locomotive) instruments, the pointer can move very smoothly on the tachometer or oil gauge.

Innovative Attack Detection Solutions for Wireless Networks With Application to Location Security

Modern wireless communication networks are threatened by new generations of radio hackers. These are skilled attackers equipped with low-cost software radios, suitably instrumented so as to monitor, degrade, or even alter the radio signals. The aim of this paper is to devise innovative detection architectures against the most common classes of threats: broadband noise jammers, whose goal is to reduce the signal-to-noise ratio, and spoofing/meaconing attacks, which aim to inject false or incorrect information into the receiver. To this end, we resort to the hypothesis testing theory and solve the associated problems by means of the GLRT possibly accounting for penalty terms. The resulting decision schemes represent the main technical novelty of this work. The analysis of their performance focuses on a location security case study for 4G/5G cellular networks. To this end, we leverage measurement models from the cellular localization literature and generate data according to these models. The numerical results show the effectiveness of the proposed approaches in comparison with suitable counterparts.

Inaudible sound covert channel with anti-jamming capability: Attacks vs. countermeasure

When an inaudible sound covert channel (ISCC) attack is launched inside a computer system, sensitive data are converted to inaudible sound waves and then transmitted. The receiver at the other end picks up the sound signal, from which the original sensitive data can be recovered. As a forceful countermeasure against the ISCC attack, strong noise can be used to jam the channel and literally shut down any possible sound data transmission. In this paper, enhanced ISCC whose transmission frequency can be dynamically changed is proposed. Essentially, if the transmitter detects that the covert channel is being jammed, the transmitter and receiver both will switch to another available frequency and re-establish their communications, following the proposed communications protocol. Experimental results show that the proposed enhanced ISCC can remain connected even in the presence of a strong jamming noise source. Correspondingly, a detection method based on frequency scanning is proposed to help to combat such an anti-jamming sound channel. With the proposed countermeasure, the bit error rate (BER) of the data communications over enhanced ISCC soars to more than 48%, essentially shutting down the data transmission, and thus neutralizing the security threat.

Implementation of Synthetic Aperture Radar Active Decoy Hardware

As a result of the military's use of synthetic aperture radar (SAR), it has become necessary to use jamming techniques to protect sensitive sites of friendly forces from being intercepted by SAR. To combat SAR sensors, two jamming techniques are typically available: noise jamming and deceptive jamming. In this paper the design and hardware implementation of a proposed active decoy which works as deceptive jamming system, is achieved using field programmable gate array (FPGA). The performance of the developed system is evaluated by SystemVue. 2015.01, using “hardware in the loop” methodology.

SPWVD-PSD 겹침 이미지를 이용한 전이학습기반 GNSS 재밍식별기법

In this paper, a transfer learning-based global navigation satellite system (GNSS) jamming classification scheme using overlapped images of the smoothed pseudo-Wigner-Ville distribution (SPWVD) and power spectral density (PSD) is proposed. Five types of jamming are considered: amplitude modulation jamming (continuous wave interference), linear chirp jamming, frequency modulation jamming, narrow-band noise jamming, and distance measurement equipment jamming (pulse jamming). The performance of the proposed scheme is shown to be the F1 score and the confusion matrix for pre-mentioned 5 jamming types with no jamming case. A representative conventional transfer learning-based GNSS jamming classification scheme uses a concatenated image comprising a spectrogram, in-phase and quadrature constellation, PSD, and histogram. However, in conventional schemes, the spectrogram

Intra-Pulse Frequency Coding Design for a High-Resolution Radar against Smart Noise Jamming

Smart noise jamming forms active jamming by intercepting, modulating, and forwarding radar signals into the radar receiver, which seriously affects the radar range recovery performance. In this paper, we propose a novel waveform design approach and an efficient range recovery method for high-resolution radar in the jamming scenario. Firstly, we propose an intra-pulse frequency-coded frequency-modulated continuous waveform (IPFC-FMCW), which contains multiple FMCW chips with different widths and frequencies, to combat the smart noise jamming. After the jamming suppression, the proposed waveform has a low sidelobe level, which is different from traditional FMCW signals for which the observations are periodically missing, resulting in high sidelobe levels. Then, to improve the range recovery performance of the waveform after jamming suppression, we optimize the range profile by designing the transmit waveform and then solve it by a simulated annealing algorithm. Next, based on the designed waveform, we derive the echo model after jamming suppression and propose a gridless compressed sensing (CS) method to recover the range of the targets. Compared with the existing waveforms and methods, the proposed waveform and the processing method achieve better range recovery performance in the jamming scenario. Numerical simulations are utilized to demonstrate the range recovery effectiveness of the proposed waveform and method in smart noise jamming.

РЕЗУЛЬТАТИ ЕКСПЕРИМЕНТАЛЬНИХ ДОСЛІДЖЕНЬ БАГАТОДІАПАЗОННОГО ІМІТАТОРА ПОСТАНОВНИКА АКТИВНИХ ШУМОВИХ ПЕРЕШКОД

The article provides information on the results of experimental studies of a multi-band hardware and software complex for simulating the action of an active noise jammer, which has been created for the training of operators of radar stations of radio engineering troops. One of the important elements of the professional training of the radar stations operators of the air defense radio engineering forces is their ability to work in difficult target and jamming conditions. The existing simulators for training operators do not fully meet the requirements of the quality of training, since they form only secondary bearing marks on the jammer manufacturer and do not reproduce the situation of deterioration of target detection conditions as a result of the simultaneous action of active and passive noise jammer, as well as the influence of the autocompensator of jammer on the quality of the radar, as it happens in real situation. The offered device for simulating the influence of active jammer has been built according to the modular principle and implemented using software-defined radio technology, which allows to quickly change both the type of signal and its parameters. Power amplifiers and antenna systems have been designed to operate in the 140–190 MHz, 470–900 MHz, and 2500–3500 MHz bands, and for experimental research radar stations in the meter, decimeter, and centimeter wave ranges have been involved. The method of using the simulator has been substantiated, and the conducted studies showed that for radar stations in which the angular beams of the directional pattern have different operating frequencies, there is an additional possibility of simulating the action of the active jammer by changing the frequency of the jammer in the case of operation of the complex directly near the suppression object, where the directional pattern of the radar station antenna has not yet been formed. The method of using the complex both for training sessions and during tactical exercises of the radio technical troops unit to simulate the action of an air-based jamming device or a dropped jamming transmitter has been substantiated. Keywords: active noise jammer; simulation; hardware and software complex; radar station; programmed radio.

Secure Transceiver Design and Power Control for Over-the-Air Computation Networks

This letter investigates the physical layer security (PLS) for over-the-air computation (AirComp) networks. We propose a self-protection scheme to safeguard AirComp networks against eavesdropping using a full-duplex fusion center (FC), which transmits jamming noise to degrade the eavesdropper’s links while receiving signals. To guarantee the secure computation of the FC, we jointly optimize the power control of senors and the transceiver of the FC to minimize the computation mean square error (CMSE) of the FC while setting the CMSE of the eavesdropper to be greater than a specific threshold. The formulated problem is nonconvex due to coupling variables, thus it is challenging to solve. We propose an alternating difference-of-convex (DC)-based algorithm to deal with it. Simulation results are provided to verify the effectiveness of our proposed scheme.

Numerical Integration-Based Performance Analysis of Amplitude-Comparison Monopulse Algorithm in Correlated Noise

In this paper, the performance analysis of the amplitude-comparison monopulse (ACM) algorithm under a correlated noise effect is dealt with. The noise received by a monopulse antenna is caused by various sources, such as jamming, multipath, clutter, and thermal noise. The noise variables caused by these noise sources may be correlated with each other when received by the antenna elements. We explicitly analyzed the angle estimation performance of the monopulse algorithm when a correlated noise is received by deriving the probability density function (PDF) of the channel noise variables. In this process, correlation coefficients between noise variables received by antenna elements are defined, and variance and correlation coefficients of channel noise variables are derived. The performance of the angle estimation is analyzed by calculating the root mean square error (RMSE) for various variances and correlation coefficients of the received noise variables. The expectation operation required for calculating the RMSE is performed via numerical integration. Consequently, the analytically derived RMSE results show excellent agreements with the Monte Carlo simulation-based RMSE result, and it is confirmed that the RMSE decreases as the correlation coefficient between the received noise variables increases. When the SNR is high and on-axis, the RMSE decreases by 20% whenever the correlation coefficient between the reception noise variables increases by 0.2.