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New Methods For The Detection And Interception Of Unknown Frequency Hopped Waveforms
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Book Synopsis New Methods for the Detection and Interception of Unknown, Frequency-hopped Waveforms by : William Edward Snelling
Download or read book New Methods for the Detection and Interception of Unknown, Frequency-hopped Waveforms written by William Edward Snelling and published by . This book was released on 1990 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis New Methods for the Detection and Interception of Frequency-Hopped Waveforms by :
Download or read book New Methods for the Detection and Interception of Frequency-Hopped Waveforms written by and published by . This book was released on 1990 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three new methods for the detection and interception of frequency - hopped waveforms are presented. First presented are two types of sequential detectors: a purely sequential test that requires less data for a decision and a truncated sequential test that requires less data even while opeating under poor signal-to-noise ratios. Performances are evaluated via theoretical, numerical, and Monte Carlo analyses. Second, compressive-receiver-based-based interceptors are presented: (1) a locally optimal detector, which is compared against the optimal channelized detectors; (2) a simplified, suboptimal scheme, which trades off duty cycle against performance; (3) and a technique for estimating hop frequency. Quantified are the performances of the optimal and suboptimal detectors. Third, a detector based on the Amplitude Distribution Function (ADF) is presented. Given is a technique for deconvolving the ADF, enabling signal and noise separation. From this, a detection statistic is defined and statistically characterized, yielding a new class of detectors. The detectors are performance analyzed. Keywords: Spread spectrum, Frequency-hopped, Electronic counter measures, Interception, Probability, Detection, Statistics.
Book Synopsis Modern Communications Jamming Principles and Techniques by : Richard Poisel
Download or read book Modern Communications Jamming Principles and Techniques written by Richard Poisel and published by Artech House. This book was released on 2011 with total page 895 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edition features a wealth of new material on urban warfare, including a computer simulation of EW architecture alternatives for land-based forces based on urban constraints. It also includes an expanded section on time-hopped spread spectrum communications, more details on modern communication system technologies such as CDMA and OFDM, and an in-depth discussion on sources of urban noise. This practical resource is focused on showing the reader how to design and build jammers specifically targeted at spread spectrum, anti-jam communications. Moreover, it gives assistance in evaluating the expected performance of jamming systems against modern communications systems, and discover the best waveform to use to counter communication systems designed to be effective in jamming environments. While mathematical derivations in general are avoided, the book presents error rate performance equations for most modern digital anti-jam communication systems
Book Synopsis Detection of Frequency-Hopped Waveforms Embedded in Interference Waveforms with Noise by :
Download or read book Detection of Frequency-Hopped Waveforms Embedded in Interference Waveforms with Noise written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bandwidth usage has become more complex such that it is not uncommon that multiple signals of appreciable power may be present within the same bandwidth. The presence of multiple signals in addition to additive white Gaussian (AWGN) increases the difficulty of detecting frequency-hopped (FH) waveforms. This paper investigates the performance of an exponential-averaging based FH detection method in the presence of interfering signals and AWGN. The detection method provides an estimate of the noise plus inference spectrum using exponential averaging and then generates an estimate of the desired signal spectrum by combining the estimated noise plus interference spectrum with the composite spectrum.
Book Synopsis Detection of Frequency-Hopped Signals Exposed to Non-Stationary Interference by :
Download or read book Detection of Frequency-Hopped Signals Exposed to Non-Stationary Interference written by and published by . This book was released on 2008 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency-hopped spread spectrum signals are widely used in military communications to help combat or suppress interference due to jamming, other users of the channel, and multipath propagation. Frequency-hopped signals may be difficult to detect when embedded in background noise. Previous research has demonstrated techniques for interference reduction and filtering frequency hopped spread spectrum waveforms with minimum distortion when the frequency-hop rate is on the order of 1,000 hops per second and the waveform is embedded in stationary interference waveforms. The objective of this thesis was to apply previously developed interference reduction techniques to frequency-hopped signals that hop at a much lower rate in order to determine the efficacy and practicality of these techniques for hop rates as low as five frequency-hops per second when the signal of- interest is embedded in non-stationary interference. The technique used in this thesis to detect the frequency-hopped signals-of-interest is based on exponential averaging in the frequency domain. This method averages a weighted data stream in real time. Specific fast Fourier transform block sizes and exponential average weights produce good results if the signal-to-interference and the signal-to-noise ratios are not too small.
Book Synopsis Detection of Frequency-Hopped Signals Embedded in Interference Waveforms by :
Download or read book Detection of Frequency-Hopped Signals Embedded in Interference Waveforms written by and published by . This book was released on 2005 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many military communications systems utilize frequency-hopped spread spectrum waveforms to protect against jamming and enemy detection. These waveforms may be subjected not only to intentional jamming but may also be unintentionally jammed by other communications signals. While some systems can overcome inband interference with more signal power, covert systems may be limited to small amounts of transmitted power. The objective of this thesis was to investigate a method for resolving a frequency-hopped signal embedded in interference waveforms. With exponential averaging in the frequency domain, the spectra of the interfering signals can be estimated as long as they are present over a period longer than that of the frequency-hopped signal. Certain FFT sizes and weights are more beneficial to achieving this estimate than others. The interference estimate can be used to extract the desired frequency-hopped signal through spectral division of the received signal with the estimate. This technique is designated as noise-normalization. Simulations in MATLAB demonstrate the use of the technique and show how the desired signal can be resolved.
Book Synopsis Detecting and Classifying Low Probability of Intercept Radar by : Phillip E. Pace
Download or read book Detecting and Classifying Low Probability of Intercept Radar written by Phillip E. Pace and published by Artech House. This book was released on 2009 with total page 893 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This comprehensive book presents LPI radar design essentials, including ambiguity analysis of LPI waveforms, FMCW radar, and phase-shift and frequency-shift keying techniques. Moreover, you find details on new OTHR modulation schemes, noise radar, and spatial multiple-input multiple-output (MIMO) systems. The book explores autonomous non-linear classification signal processing algorithms for identifying LPI modulations. It also demonstrates four intercept receiver signal processing techniques for LPI radar detection that helps you determine which time-frequency, bi-frequency technique best suits any LPI modulation of interest."--Publisher.
Book Synopsis Detection of Frequency-hopped Signals Embedded in Non-stationary Interference by : Steven C. Layfield
Download or read book Detection of Frequency-hopped Signals Embedded in Non-stationary Interference written by Steven C. Layfield and published by . This book was released on 2008 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency-hopped spread spectrum signals are widely used in military communications to help combat or suppress interference due to jamming, other users of the channel, and multipath propagation. Frequency-hopped signals may be difficult to detect when embedded in background noise. Previous research has demonstrated techniques for interference reduction and filtering frequency-hopped spread spectrum waveforms with minimum distortion when the frequency-hop rate is on the order of 1,000 hops per second and the waveform is embedded in stationary interference waveforms. The objective of this thesis was to apply previously developed interference reduction techniques to frequency-hopped signals that hop at a much lower rate in order to determine the efficacy and practicality of these techniques for hop rates as low as five frequency-hops per second when the signal-of-interest is embedded in non-stationary interference. The technique used in this thesis to detect the frequency-hopped signals of interest is based on exponential averaging in the frequency domain. This method averages a weighted datastream in realtime. Specific fast Fourier transform block sizes and exponential average weights produce good results if the signal-to-interference and the signal-to-noise ratios are not too small.
Book Synopsis American Doctoral Dissertations by :
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1990 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Signal Detection and Jammer Localization in Multipath Channels for Frequency Hopping Communications by :
Download or read book Signal Detection and Jammer Localization in Multipath Channels for Frequency Hopping Communications written by and published by . This book was released on 2005 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency hopping (FH) is the prevailing spread spectrum method in military communications, largely due to its low probability of detection and interception. In this project we developed a novel signal processing scheme for code-blind reception of multiple frequency hopped transmissions over multipath channels. This technique is based on the principle of dynamic programming and/or expectation-maximization, coupled with multidimensional harmonic and low-rank analysis. It is able to jointly estimate hop timing, hop frequency, and direction-of-arrival (DOA) of multiple FH signals in the presence of frequency collisions, without the knowledge of signal hop patterns. The method can also be used to obtain locate information and operation characteristics of active FH jammers. The associated identifiability of 2-D and multidimensional frequency estimation is also investigated.
Book Synopsis Engineering Communication by : Er. Amit Tiwari
Download or read book Engineering Communication written by Er. Amit Tiwari and published by BFC Publications. This book was released on 2021-04-18 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a basic book of communication for final year engineering students of electronics and communication branch. It will help them to get a better understanding of communication and FHSS. It will help them to visualise the things. I have also mentioned about the experiments and practical i have performed in this regard. I hope it helps you to find an answer to your doubts and further help you in your future career.
Book Synopsis Wavelet Analysis of Instantaneous Correlations with Application to Frequency Hopped Signals by : Nabil Hamdy Shaker Khalil
Download or read book Wavelet Analysis of Instantaneous Correlations with Application to Frequency Hopped Signals written by Nabil Hamdy Shaker Khalil and published by . This book was released on 1997-09-01 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency hopped signals are widely used in various communication applications for their inherent security features. The demand, by civilian and governmental agencies, to intercept communication signals is increasing. The interception task can be summarized by detecting the signal's presence in additive noise, classifying the modulation type, estimating the control parameters, decoding the data, and decrypting the information content. This work addresses the merging of wavelet and correlation concepts to detect, classify and estimate the parameters of frequency hopped signals. We address the interception problem in two ways. The first approach is based on a visual inspection of the wavelet surfaces generated from the instantaneous correlation function of the communication signal and leads to hop start/stop times estimates. In the second approach, we apply an energy-based processing scheme to estimate the hop start and stop times, the hop scale pattern, and the hop frequency. Results show that frequency hopped signals can be identified at an SNR of 3 dB or 6 dB using visual inspection or an automated scheme, respectively.
Download or read book Science Abstracts written by and published by . This book was released on 1993 with total page 2332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conference Record written by and published by . This book was released on 1995 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Spread Spectrum Systems for GNSS and Wireless Communications by : Jack Kenneth Holmes
Download or read book Spread Spectrum Systems for GNSS and Wireless Communications written by Jack Kenneth Holmes and published by Artech House Publishers. This book was released on 2007 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge resource offers a modern treatment of spread spectrum (SS) communications, including direct sequence and frequency hopping. This comprehensive volume presents the principles of design and analysis for all SS systems, and places special emphasis on wireless systems and global navigation satellite systems (GNSS).
Book Synopsis Military Communications in a Changing World by :
Download or read book Military Communications in a Changing World written by and published by . This book was released on 1991 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Principles of Spread-Spectrum Communication Systems, Second Edition by : Don Torrieri
Download or read book Principles of Spread-Spectrum Communication Systems, Second Edition written by Don Torrieri and published by Springer Science & Business Media. This book was released on 2011-07-15 with total page 589 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise but lucid explanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles. Throughout the book, learning is facilitated by many new or streamlined derivations of the classical theory. Problems at the end of each chapter are intended to assist readers in consolidating their knowledge and to provide practice in analytical techniques. The choice of specific topics is tempered by the author’s judgment of their practical significance and interest to both researchers and system designers. The evolution of spread spectrum communication systems and the prominence of new mathematical methods in their design provided the motivation to undertake this new edition of the book. This edition is intended to enable readers to understand the current state-of-the-art in this field. More than 20 percent of the material in this edition is new, including a chapter on systems with iterative channel estimation, and the remainder of the material has been thoroughly revised.
