Download or read book Interception and Demodulation of Slow Frequency hopped Differential Phase Shift Keyed Signals Using Envelope Detection and Pattern Recognition written by Scott Michael Koziol and published by . This book was released on 2000 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a novel non-coherent wireless communication receiver design for intercepting and demodulating frequency hopping spread spectrum (FHSS) signals. This interception receiver is based upon phase modulation to amplitude modulation conversion (PM to AM), and is specifically designed for demodulating a slow frequency-hopped signal that has differentially encoded phase shift keying (DPSK) modulation. The receiver will also demodulate non-frequency hopped DPSK signals. Matlab(Superscript Trade Mark Symbol) simulations show that if a signal has a signal to noise ratio (SNR) greater than approximately 30 dB, the intercept receiver can demodulate it by using the following: a bank of filters for PM to AM conversion, envelope detectors for each filter in the bank, and a pattern recognition algorithm that processes the envelope detector outputs, combines them, and maps the result into bits. The performance of the receiver is characterized with simulations and analytical calculations.
Download or read book Master s Theses Directories written by and published by . This book was released on 2001 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Education, arts and social sciences, natural and technical sciences in the United States and Canada".
Download or read book Synchronization and Demodulation of Differential Phase Shift Keyed Signals with Linear Surface Acoustic Wave Devices written by Rudolf W. Burgi and published by . This book was released on 1984 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Imperfectly timed Demodulation of Differential Phase Shift Keyed Signals written by Ronald J. Huff and published by . This book was released on 1969 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of bit synchronization error on the performance of receivers used to demodulate differential phase shift keyed (DPSK) signals are analyzed. In the two cases of interest considered, the carrier signal is bi-phase modulated with either the differentially encoded (binary) data stream or the modulo two sum of the encoded data stream and a binary pseudo-noise (PN) signal. The bit timing error is assumed to be Gaussian distributed. Since the effects of both non-zero timing offset and random jitter are investigated, the results provide an adequate basis for the design of synchronizers as employed, for example, in time division multiple access systems. (Author).
Download or read book Quasi Coherent Demodulation of Phase Shift Keyed Signals written by A. Ghosh and published by . This book was released on 1976 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quasi coherent Demodulation of Phase shift keyed Signals written by Amitabha Ghosh and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major part of the work described in the thesis is a study of a novel technique for the demodulation of two level phase shift keyed signals. Its advantage over conventional coherent demodulation methods is that it uses a free running oscillator as the local oscillator in the receiver, which is not locked to the transmitted carrier signal. Thus this novel system does not require the complex synchronisation techniques used in conventional phase shift keyed demodulators. This new demodulator like conventional coherent demodulators has not got the fixed speed disadvantage of differential phase shift keying. This new demodulator also referred to as a Quasi-Coherent demodulator has been characterised both theoretically and experimentally and compared with conventional coherent and differential phase shift-keyed systems. The possibility of extending this technique to multiphase phase shift keyed system is also discussed. The performance of a multilevel coherent phase shift keyed system in the presence of interference can be predicted by computing the exact mathematical equation for the error rate. In the thesis an approximate, but quick and simple method has been developed to, predict the performance of multilevel coherent phase shift keyed system from the well known result of a two level coherent phase shift keyed system. In all the interference analysis so far done by other authors, it is assumed that the reference at the receiver is coherent with the received signal. However, it is evident that in the presence of a strong interference, a phase locked loop derived reference will in general be coherent with the composite signal (i.e. signal plus interference plus noise) and not with the signal as assumed by previous authors. The effect of such a reference i.e. coherent with the composite signal on the performance of a two level system has been discussed fully in chapter four. The performance of a digital system also depends on the receiving filter characteristic and on the sampling jitter that is inevitably present in the sampling pulse in the decision circuitry of the receiver. The effect of these two factors on the performance of a two level coherent phase shift keyed system has been fully discussed in chapter five.
Download or read book Robust Detection Schemes for Frequency Shift Keyed and Phase Shift Keyed Signals written by J. Krishnamurthy and published by . This book was released on 1972 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two Robust Detection Schemes for the detection of a class of time varying signals in additive disturbance are proposed and analyzed and their performance is evaluated. The proposed detection schemes, called Robust Detection Scheme I (RDSI) and Robust Detection Scheme II (RDSII) are applicable when the samples of the received signal or a filtered version of the received signal contain pure signal components that are all equal. It is shown that both binary and M-ary Phase Shift Keyed and Frequency Shift Keyed Signals can be detected by using RDSI and RDSII. The performance of the detectors is compared with that of the Mean and Sign detectors. It is observed that the proposed detectors generally lead to lower probability of error, except when the Mean and the Sign detectors are the Maximum Likelihood detectors. Analytical expressions for the average probability of error, the asymptotic relative efficiency and the asymptotic efficiency are derived and it is shown that the proposed detectors are superior or equivalent to the Sign detector and superior to the Mean detector in nongaussian noise. (Author).
Download or read book A Hard Decision Receiver for a Frequency hopped Spread spectrum Communication System Using Differential Phase shift Keying written by Rodger A. Barrow and published by . This book was released on 1985 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Imperfect Differential Detection of a Biphase Modulated Signal written by Thomas William Miller and published by . This book was released on 1971 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enabling Technologies for Direct Detection Optical Phase Modulation Formats written by Xian Xu and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Automatic Recognition and Demodulation of Digitally Modulated Communications Signals Using Wavelet domain Signatures written by Ka Mun Ho and published by . This book was released on 2010 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wavelet transform-based methodologies for both Automatic Modulation Recognition (AMR) and Demodulation of digitally modulated communications signals can be utilized in an enabling platform for the implementation of a new class of communications systems. In particular, such techniques could enable the development of agile radio transceivers for use in both commercial and military applications. Such radio transceivers would have the ability to transmit and receive signals using many different modulation schemes while employing a common receiver architecture based on a single demodulator. In this dissertation, the development of AMR and Demodulation techniques are based on the relatively new mathematical theory of Wavelet Transforms (WTs). Information-bearing signals acquired by communications receivers are transformed into the wavelet-domain using the Continuous Wavelet Transform (CWT) and then applied to signal processing algorithms that also use the CWT in conjunction with pattern recognition techniques. In particular, the method of template-matching is used for both the AMR and Demodulation processes. Signal templates characterizing various modulated signals are used for both processes. The signal templates are determined based on the signal features present in the fractal patterns of their corresponding scalograms for specific modulation schemes as they appear in the wavelet-domain. The algorithms developed in this work are capable of both classifying the method of modulation used in the acquired signal, as well as subsequently automatically demodulating the signal to recover the message. The classes of digitally modulated signals considered in this work include variants of the Amplitude-, Frequency-, Phase-Shift Keying modulation families, i.e., ASK, FSK, and PSK, respectively, and multiple-level Quadrature Amplitude Modulation (M-ary QAM) families. The AMR and Demodulation performances are evaluated in the presence of Additive White Gaussian Noise (AWGN) over a wide range of Signal-to-Noise Ratio (SNR) values. Through extensive Monte Carlo computer simulations it is determined that the average correct classification rates using wavelet-based AMR for PSK, ASK, and QAM are over 98%, and over 90% for FSK signals, all at an SNR of 0 dB. The Bit Error Rate (BER) performance obtained using wavelet-based Demodulation is at least one order of magnitude better than the matched filter-based BER performance realized for the modulation schemes considered.
Download or read book Direct Differential Detection of Phase Shift Keyed Signals written by Israel Bar-David and published by . This book was released on 1992 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detection of Continuous Phase Frequency Shift Keyed Signals written by John Priyantha Fonseka and published by . This book was released on 1985 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extended Phase shift Keying written by Earl William Jr McCune and published by . This book was released on 1998 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectra of Phase shift Keyed Signals Using Rectangular Modulation written by A. J. I. Fletcher and published by . This book was released on 1966 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Use of Polarity Concidence Correlation Techniques for Differential Phase Shift Key Demodulation written by William Franklin Lawrence and published by . This book was released on 1975 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase shift keyed Signal Detection with Noisy Reference Signals written by William C. Lindsey and published by . This book was released on 1966 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt:
