Differentially Coherent Demodulation in Phase-shift-keying PDF Download

Author: Fawaz Raffoul Bassim
Publisher:
ISBN:
Category :
Languages : en
Pages : 226

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Author: Amitabha Ghosh
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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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.

Author: A. Ghosh
Publisher:
ISBN:
Category :
Languages : en
Pages : 212

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Author: Osama Mohamed El-Ghandour
Publisher:
ISBN:
Category :
Languages : en
Pages : 188

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Author: Tahir Conka
Publisher:
ISBN: 9781423560920
Category :
Languages : en
Pages : 90

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In this thesis, the performance analysis of a non-coherent Differential Phase Shift Keying (DPSK) receiver using Post-Detection Selection Combining techniques over a Rayleigh fading channel is investigated. Post- Detection Selection Combining (PDSC) is evaluated and compared to Equal Gain Combining (EGC) and Selection Combining (SC), the two common diversity techniques discussed in the literature. Numerical results obtained for Post- Detection Selection Combining are compared to Selection Combining and Equal Gain Combining. The Post-Detection Selection Combining method is shown to be superior to the Selection Combining method but inferior to Equal Gain Combining method for a non-coherent DPSK receiver operating over a Rayleigh fading channel.

Author: Shi Hong (M.E.)
Publisher:
ISBN:
Category : Artificial satellites in telecommunication
Languages : en
Pages : 314

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Author: Marvin K. Simon
Publisher: John Wiley & Sons
ISBN: 0471726184
Category : Technology & Engineering
Languages : en
Pages : 244

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An important look at bandwidth-efficient modulations with applications to today's Space program Based on research and results obtained at the California Institute of Technology's Jet Propulsion Laboratory, this timely book defines, describes, and then delineates the performance (power and bandwidth) of digital communication systems that incorporate a wide variety of bandwidth-efficient modulations appropriate for the design and implementation of space communications systems. The author compares the performance of these systems in the presence of a number of practical (non-ideal) transmitter and receiver characteristics such as modulator and phase imbalance, imperfect carrier synchronization, and transmitter nonlinearity. Although the material focuses on the deep space applications developed at the Jet Propulsion Laboratory, the presentation is sufficiently broad as to be applicable to a host of other applications dealing with RF communications. An important contribution to the scientific literature, Bandwidth-Efficient Digital Modulation with Application to Deep Space Communications * was commissioned by the JPL Deep Space Communications and Navigation System Center of Excellence * highlights many NASA-funded technical contributions pertaining to deep space communications systems * is a part of the prestigious Deep Space Communications and Navigation Series The Deep Space Communications and Navigation Series is authored by scientists and engineers with extensive experience in astronautics, communications, and related fields. It lays the foundation for innovation in the areas of deep space navigation and communications by disseminating state-of-the-art knowledge in key technologies.

Author: Richard W. Middlestead
Publisher: John Wiley & Sons
ISBN: 1119011841
Category : Technology & Engineering
Languages : en
Pages : 828

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This book uses a practical approach in the application of theoretical concepts to digital communications in the design of software defined radio modems. This book discusses the design, implementation and performance verification of waveforms and algorithms appropriate for digital data modulation and demodulation in modern communication systems. Using a building-block approach, the author provides an introductory to the advanced understanding of acquisition and data detection using source and executable simulation code to validate the communication system performance with respect to theory and design specifications. The author focuses on theoretical analysis, algorithm design, firmware and software designs and subsystem and system testing. This book treats system designs with a variety of channel characteristics from very low to optical frequencies. This book offers system analysis and subsystem implementation options for acquisition and data detection appropriate to the channel conditions and system specifications, and provides test methods for demonstrating system performance. This book also: Outlines fundamental system requirements and related analysis that must be established prior to a detailed subsystem design Includes many examples that highlight various analytical solutions and case studies that characterize various system performance measures Discusses various aspects of atmospheric propagation using the spherical 4/3 effective earth radius model Examines Ionospheric propagation and uses the Rayleigh fading channel to evaluate link performance using several robust waveform modulations Contains end-of-chapter problems, allowing the reader to further engage with the text Digital Communications with Emphasis on Data Modems is a great resource for communication-system and digital signal processing engineers and students looking for in-depth theory as well as practical implementations.

Author: Fuqin Xiong
Publisher: Artech House Publishers
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 1056

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Book Description
This newly revised and expanded edition of an Artech House classic builds on its success as far and away the most comprehensive guide to digital modulation techniques used in communications today. The second edition adds a wealth of up-to-date, critical material, including: Five new chapters devoted to orthogonal frequency division multiplexing (OFDM) covering its basics and practical implementation issues: peak-to-average power ratio (PAPR) reduction, synchronization, fading channel performance, and mitigation methods, as well as the newest developments such as wavelet OFDM schemes; New modulations for optical communications; Enhanced coverage of M-ary amplitude shift keying (ASK); More accurate bit error rate (BER) equations for quaternary phase shift keying (QPSK) and quadrature amplitude modulation (QAM); Enhanced coverage of fading channel mitigation methods such as channel estimate and diversity techniques; Fast-access comparison of all modulation schemes; New appendixes covering trigonometry identities, Fourier transform pairs and properties, and Q-function and error function values.

Author: Francis C.M. Lau
Publisher: Springer Science & Business Media
ISBN: 9783540006022
Category : Computers
Languages : en
Pages : 244

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One of the first books in this area, this text focuses on important aspects of the system operation, analysis and performance evaluation of selected chaos-based digital communications systems – a hot topic in communications and signal processing.