Download or read book Detection and Classification of Frequency hopped Spread Spectrum Signals written by James Eric Dunn and published by . This book was released on 1991 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detectability of Spread spectrum Signals written by Robin A. Dillard and published by Artech House Radar Library (Ha. This book was released on 1989 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: A desktop reference for designers of military communication systems using spread-spectrum techniques to achieve a low probability of intercept. Shows how to evaluate the detectability of candidate signal structures mathematically, and to select signal parameters that minimize the probability of dete
Download or read book Spread Spectrum Systems written by Robert Clyde Dixon and published by Wiley-Interscience. This book was released on 1984 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
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.
Download or read book Fundamentals of Spread Spectrum Modulation written by Rodger E. Ziemer and published by Morgan & Claypool Publishers. This book was released on 2007-12-01 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spectrum system is the code synchronization, which is usually broken down into the operations of acquisition and tracking. Means for performing these operations are discussed next. Finally, the performance of spread spectrum systems is of fundamental interest and the effect of jamming is considered, both without and with the use of forward error correction coding. The presentation ends with consideration of spread spectrum systems in the presence of other users. For more complete treatments of spread spectrum, the reader is referred to [1, 2, 3].
Download or read book Spread Spectrum Communications Handbook Electronic Edition written by Marvin K. Simon and published by McGraw Hill Professional. This book was released on 2001-09-22 with total page 1250 pages. Available in PDF, EPUB and Kindle. Book excerpt: The acknowledged Spread-Spectrum Bible the most complete reference in the field! INCLUDESCD-ROM CONTAININGTHE ENTIRE BOOKIN FULLY-SEARCHABLE PDF Spread-spectrum systems have found important commercial applications in CDMA cellular networks and wireless personal communication networks. Communications engineers and technicians now have ready access to a wealth of spread-spectrum information in this exhaustive handbook the most comprehensive and authoritative compendium on spread-spectrum systems available anywhere. Written by recognized authorities in the field, the Handbook presents both theoretical basics and practical applications, providing succinct, results-oriented solutions to engineering problems. Starting with basic concepts and system models, the book covers: Anti-jamming communication systems Coherent direct-sequence systems Non-coherent frequency-hopped systems Coherent and differentially coherent modulation techniques Pseudonoise acquistion and tracking in direct sequence receivers Time and frequency synchronization of frequency-hopped receivers Low probability of intercept communications In addition, it offers an in-depth look at multiple access communications and positioning systems and discusses the growth of spread-spectrum applications. INCLUDES CD-ROM CONTAINING THE ENTIRE BOOK IN FULLY SEARCHABLE PDF
Download or read book On the Acquisition of Frequency hopped Spread Spectrum Signals in Jamming written by Peter Regent Pawlowski and published by . This book was released on 1986 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spread Spectrum Communications written by Marvin K. Simon and published by . This book was released on 1985 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Spread spectrum Communications written by Roger L. Peterson and published by Pearson. This book was released on 1995 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: Besides the traditional military application areas, there is a growing and intense interest in spread spectrum communications systems for evolving civil applications, e.g., cellular-mobile communications, personal communications, and satellite-mobile communications. Ideal for those who need to get up to speed or current quickly in this area, this self-contained exploration of spread spectrum system analysis and applications provides a solid theoretical background along with an abundance of examples of specific analysis/design situations, and exposes readers to the most recent research and developments in the field. Covers basic digital communication and spread spectrum concepts, and features exceptionally complete treatments of important hot topics such as spectrum spreading sequences; the code acquisition and tracking process; the effects of jamming on spread spectrum communications and the use of coding/interleaving to combat the detrimental effects of jamming; designing spread spectrum systems for low probability of the intercept; and the design of code division multiple access systems, wit h examples. Contains a complete set of technical appendices. For electrical engineers and others with a background in linear systems and probability/random processes who want a cutting-edge overview of the principles, research, and developments of spread spectrum systems.
Download or read book Detection and Estimation of Frequency Hopping Signals Using Wavelet Transforms written by Howard F. Overdyk and published by . This book was released on 1997-09-01 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the use of wavelet transforms in the detection and estimation of spread spectrum frequency hopping signals. The technique developed in this work makes only two basic assumptions of a minimum hopping time and a minimum frequency hopping differential. The approach is based on the phase information of the temporal correlation function and the resulting discrete wavelet transform is used to estimate the hopping time of frequency hopping signals. Results show the proposed scheme is robust to additive white noise for SNR levels of 3 dB and above.
Download or read book Modern Communications and Spread Spectrum written by George R. Cooper and published by McGraw-Hill Companies. This book was released on 1986 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spread Spectrum Techniques written by Robert Clyde Dixon and published by . This book was released on 1976 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Spread Spectrum Signal Characteristic Estimation Using Exponential Averaging and an Ad hoc Chip Rate Estimator written by and published by . This book was released on 2007 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation investigates two methods of spread spectrum (SS) signal characteristic estimation for the two principle types of SS systems, frequency-hopped (FH) and direct sequence SS. The exponential averaging detector is used to detect and estimate the hopped frequencies for a SS-FH signal in the presence of interference signals as well as additive-white-Gaussian-noise (AWGN). The detection method provides an estimate of the AWGN plus interference spectrum using exponential averaging and then generates an estimate of the desired signal spectrum by combining the estimated AWGN plus interference spectrum with the composite (desired signal plus interference plus AWGN) spectrum. Finally, this dissertation evaluates the detector's performance as a function of the exponential coeeficient, the combining method, the probability of false alarm, signal-to-AWGN ratio, and signal-to-interference ratio. The second method of SS signal characteristic estimation uses a signal ad-hoc chip rate estimator (ACRE). The ACRE is used to estimate the chip rate of a half-sine pulse shaped SS direct-sequence signal. The Acre is explained in relation to its similarities and contrasts to the chip rate detector. The components and performance of the ACRE are presented for standard-ACRE. ACRE with additional filtering, and ACRE with incrementing. The additional filtering results in a reduced chip rate search range but yields improved estimation performance and incrementing has the potential for parallel processing, resulting in dramatically decreased computational time, without loss of performance.
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.
Download or read book Spread Spectrum Signal Design written by David L. Nicholson and published by Computer Science Press, Incorporated. This book was released on 1988 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
