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Radio frequency fingerprinting (RFF) based on RF transients is one of the most effective techniques for improving wireless security. For an efficient RFF development, RF transients need to be accurately detected. However, the detection of the transient starting point remains a main challenge due to the channel noise. In the literature, several methods have been presented to detect the starting point of the transient signals. As an alternative to these methods, this study proposes a method that utilizes Energy Criterion (EC) technique for the first time. In order to test its performance, firstly, an extensive dataset consisting of Wi-Fi signals recorded under realistic Signal-to-Noise Ratio (SNR) conditions is created. Using the provided dataset, the proposed method as well as common transient detection methods are employed for transient start detection. Then, the effect of SNR on the performance of transient start detection is evaluated. Moreover, a performance comparison between the methods is provided based on their respective computational speed and complexity. The results prove the feasibility and efficiency of the proposed method to detect the transient starting point for RFF of Wi-Fi device identification. As to the knowledge of the authors, this study is the first report that comparatively assesses the transient detection methods by using extensive data under realistic noise conditions. This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ 115613

Radio frequency fingerprinting (RFF) is based on identification of unique features of RF transient signals emitted by radio devices. RF transient signals of radio devices are short in duration, non-stationary and nonlinear time series. This paper evaluates the performance of RF fingerprinting method based on variational mode decomposition (VMD). For this purpose, VMD is used to decompose Bluetooth (BT) transient signals into a series of band-limited modes, and then, the transient signal is reconstructed from the modes. Higher order statistical (HOS) features are extracted from the complex form of reconstructed transients. Then, Linear Support Vector Machine (LVM) classifier is used to identify BT devices. The method has been tested experimentally with BT devices of different brands, models and series. The classification performance shows that VMD based RF fingerprinting method achieves better performance (at least 8% higher) than time-frequency-energy (TFED) distribution based methods such as Hilbert-Huang Transform. This is demonstrated with the same dataset but with smaller number of features (nine features) and slightly lower (2-3 dB) SNR levels.

This paper presents a simple approach to characterize the effects of scattering objects around indoor links at 28 GHz while the link is fully blocked by a human body. The effects of scattering objects nearby the link were studied by conducting measurements with a metallic reflector and the human body. Here, the basic mechanisms of wave propagation, such as reflection and diffraction, were accounted for each scattering object. To predict the attenuation caused by the metallic reflector, a specular reflection model was employed in reflection modeling. In diffraction modeling, on the other hand, the double knife-edge diffraction (DKED) model was exploited to predict the attenuation by the human body. Simulations were then compared with measurements to evaluate the prediction accuracy of the models. Results indicate that the presented simple models work well for indoor links. Therefore, the results of this paper could be extended to model multiple human bodies near the indoor links of fifth generation (5G) systems.

© 2019 IEEE.This paper presents design considerations and implementation of linear wireless sensor networks (LWSNs) to be used in cathodic protection (CP) monitoring of oil and natural gas pipelines. Firstly, the paper overviews the CP monitoring system of pipelines. Then, it presents the proposed design of LWSN along with some implementation details by providing high-level design illustrations and system parameters. Moreover, some hardware and software design issues and challenges are addressed briefly. LWSN based CP monitoring system is designed for the use in high rise mountains along with deep valleys, and some other extreme or unattended locations where communication infrastructure is unavailable, or there exists limited or interrupted access to the infrastructure.

Digital Radio Frequency Memory (DRFM) is a method that is used to capture radar threat signals, and retransmit them by changing their parameters in order to deceive or manipulate radar threats. Range gate pull-off (RGPO) technique is widely used in DRFM methods. RGPO can be either linear or parabolic RGPO according to the applied pull-off function. In this study, firstly, analytical derivations for temporal and spectral analysis of discrete form of linear and parabolic RGPO signals are presented. Then, various scenarios dependent on the parameters of pull-off function are created. Finally, simulation results regarding the scenarios are presented.

In this work, simulations and preliminary measurement results of an S-band FMCW radar is presented. A commercial simulation tool (AWR-VSS) has been used at system level design stage of the radar. The simulation tool provides all functions regarding with transmitter, target and receiving blocks, and it finally feeds echo signals to the digital processing block implemented in MATLAB. The target range and velocity have been derived for simple target scenario in MATLAB. Then, a modular RF front end of the radar has been designed using commercial of the shelf (COTS) components. The radar system has been proved to be working in indoor environment using measurement equipment. Moreover, design of horn antennas for transmitting and reception blocks have been demonstrated. Real time signal processing functions will be developed at the next stage.

21st Signal Processing and Communications Applications Conference (SIU) -- APR 24-26, 2013 -- CYPRUS, WOS: 000325005300140, Electronic Support Measures (ESM) plays an important role in modern Electronic Warfare (EW) systems. The main purpose of an ESM system is to intercept as many emissions as it can, and then to deinterleave mixed streams of pulses that are interleaved in natural time of arrival order, and thus to identify surrounding emissions. In real life, such systems may encounter with a continuous stream of pulses accompanied by many imperfections, and it should work on real-time basis. In order to handle such circumstances and to develop better deinterleaving algorithms, a simulation tool is needed. In this study, design of a scenario-based mixed pulse generator (simulator) is presented.

Specific Emitter Identification(SEI) methods are used in intercept systems for differentiating of same type of emitters in the environment. Most of the SEI implementations are designed for post processing (off line) by operators. This paper presents preliminary results on real time (on line)implementation of a SEI method on signals after the IF stage, i.e, video signals after the detector section. Initially, only the envelope of the pulses are considered in SEI processing. Pulse width and energy are two main parameters used in SEI algorithm developed. On the other hand, one of the main problems in operational environments is multipath distotion on received pulses. Most of the SEI algorithms require higher SNR figures for providing reliable results. Moreover, creating and running of a library is another issue. This paper presents various approaches in both processing of multipath distorted pulses and wavelet based library creating methods on real-time SEI implementation for an intercept receiver.

In this paper, design and fabrication of a circular horn antenna is presented. The antenna is designed for experimental use at Ka band. The design process includes feeding structure for coaxial line and geometrical parameters of the antenna. The bandwidth of the antenna is measured as 2.25GHz, (S 11 ≤−10dB) which satisfies the requirements of targeted experimental study. A reference monopole is also designed for the measurements of antenna parameters. Antenna radiation pattern is measured with the reference monopole antenna using a VNA (S 12 ) instead of typical signal generator/spectrum analyzer pair. Accuracy of antenna parameters along with the errors made in fabrication process is also discussed in the paper.

Most of discoveries indicate that the best way to overcome diabetes is to prevent the risks of diabetes before becoming a diabetic. With this opinion, we would like to find a way to estimate diabetes risk, according to some variables such as age, total cholesterol, gender or shape of the body. Due to having fuzzy input and output (glucose rate) values and because of that dependent variable have more than 2 values (unlike binary logic), ANFIS and Multinomial Logistic Regression should be executed for comparison. Then the results were benchmarked. As a result, in case of that there is a system which contains fuzzy inputs and output, ANFIS gives better results than Multinomial Logistic Regression for diabetes diagnosis.

In this work, improvements on propagation prediction models based on ray tracing in coverage estimation for digital broadcasting systems are presented. For this purpose, firstly, propagation models based on Geometrical Theory of Diffraction (GTD) are discussed, and then an improved model is proposed for prediction of propagation path loss or electric field strength at the receiver. The proposed model incorporates first order expansion of classical GTD in field computation and convex hull for ray tracing. Simulation results are presented for comparison of various models in terms of computation time and accuracy.

Date of Conference: 22-24 May 2008 Conference name: 11th International Conference on Optimization of Electrical and Electronic Equipment, 2008 In the last decade, the effect of internet usage in education is gradually increased. When we look from academic perspective, the new technologies provided alternatives for students learning. As distance education becomes important everyday, the indispensable elements of teaching and education, laboratories must be reachable via remote connection. Consequently, the education that is going to be given to the students will be more flexible with respect to place and time constraints and students can reach laboratory facilities at any time and anywhere not only in lectures and practical hours. In this study, European Remote Radio Laboratory (ERRL) which is a distance remote Radio Frequency (RF) laboratory designed for electrical-electronics students, is described generally. The software architecture, infrastructure and experiment that can be done with a remote connection have been described.

This paper presents, first, a short survey of remote laboratory initiatives in electrical and computer engineering, and then discusses design and development phases of remote laboratory environment on radio communications, the ERRL (European Remote Radio Laboratory). As being the first. attempt in establishing of such a large scale remote laboratory on radio communications, ERRL enables access to high technology RF equipments and setups through the Internet. The software structure, target groups and experimental set ups of ERRL are shortly discussed. First attempts on implementation of pilot experiments are discussed.

A remote laboratory platform enables the learners to access physical instruments at distant location and to perform experiments remotely via the Internet. This paper focuses on a pilot remote laboratory experiment on measurement of scattering parameters (s parameters) by using vector network analyzer (VNA) in the ERRL (European Remote Radio Laboratory) platform. The results of the pilot experiment are presented, and discussed shortly.

The effects of local objects and in particular, human body shadowing in and around radio link on the UWB channels have been studied. In outdoor environments, human body blockage causes deep fades, and is perceptible. In indoor environments, since there are objects nearby the radio link, radio waves diffracting around the body and reflecting from nearby objects would contribute to the received signal, and fades margin is relatively smaller than the outdoor case. When the radio link is blocked by human body, the duration and depth of fades are correlated with the blocking rate of the person, and at full blockage fades of 10-15 dB or even more are observed at different frequencies. When the link is obstructed by a wall (or other objects) in addition to human body, fades due to human body blockage becomes imperceptible at some frequencies.

We present measurement results at 2.45 GHz to evaluate blockage/shadowing and fading effects due to furniture and people next to terminals for short range indoor communication systems. The following are the results: people crossing the link near to a terminal can cause fading of up to 20 dB, which is more than the measured furniture blockage of about 5-13 dB, depending on objects over the link; polarization coupling was also measured, by using a dual polarized antenna at the receiving end, and coupling is higher for obstructed links, which suggests the use polarization diversity (see Kim, S., "Modeling and Analysis of Indoor Wireless Communication Channel", Ph.D. Thesis, Polytechnic University, Brooklyn, 1995).