Performance of DS-CDMA Communication Systems with Generalized Offset QPSK Modulation PDF Download

Author: Mohamed Adnen Landolsi
Publisher:
ISBN:
Category :
Languages : en
Pages : 330

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Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781723747366
Category : Science
Languages : en
Pages : 40

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This article considers a quaternary direct-sequence code-division multiple-access (DS-CDMA) communication system with asymmetric quadrature phase-shift-keying (AQPSK) modulation for unequal error protection (UEP) capability. Both time synchronous and asynchronous cases are investigated. An expression for the probability distribution of the multiple-access interference is derived. The exact bit-error performance and the approximate performance using a Gaussian approximation and random signature sequences are evaluated by extending the techniques used for uniform quadrature phase-shift-keying (QPSK) and binary phase-shift-keying (BPSK) DS-CDMA systems. Finally, a general system model with unequal user power and the near-far problem is considered and analyzed. The results show that, for a system with UEP capability, the less protected data bits are more sensitive to the near-far effect that occurs in a multiple-access environment than are the more protected bits.Wang, C.-W. and Stark, W.Jet Propulsion LaboratoryQUADRATURE PHASE SHIFT KEYING; BINARY PHASE SHIFT KEYING; ASYMMETRY; CODE DIVISION MULTIPLE ACCESS; PHASE SHIFT KEYING; MULTIPLE ACCESS; PROTECTION; RELIABILITY ANALYSIS

Author: Marvin K. Simon
Publisher: Wiley-Interscience
ISBN:
Category : Mathematics
Languages : en
Pages : 582

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A unified presentation, broad coverage, single-volume convenience This timesaving reference provides a unified approach to the performance analysis of digital communication systems over generalized fading channels. Employing alternative forms of such classical mathematical functions as the Gaussian Q-function, the Marcum Q-function, and the incomplete Gamma function, the book expresses communication system error probability performance in terms of the moment generation function (MGF) of the fading process. This MGF-based approach provides the unifying backbone of the book. Digital Communication over Fading Channels discusses in detail coherent, differentially coherent, and noncoherent communication systems as well as a large variety of fading channel models typical of communication links found in the real world. Coverage also includes single- and multichannel reception and, in the case of the latter, a large variety of diversity types. For each combination of communication type, channel fading model, and diversity type, the average bit error rate and/or symbol error rate is expressed in an easy-to-evaluate form. Special features include: * Important results previously scattered over many publications-now in a single volume * Simplified results heretofore available only in complex forms * Extremely broad coverage of topics * Explores practical applications, including the problem of optimum combining in the presence of co-channel interference

Author: Dr. Paulo Silva
Publisher: River Publishers
ISBN: 8792982816
Category : Technology & Engineering
Languages : en
Pages : 264

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Future broadband wireless communication systems are expected to be able to offer new and powerful services enabling fast transmission rates of several tens of Mbit/s. This is an ambitious challenge especially for mobile communication systems since these systems should be able to cope with severely time dispersive channels, associated to the signal multipath propagation. Moreover, these systems should have high spectral and power efficiencies, as well as high capacity and flexibility. Spread spectrum techniques, particularly coded division multiple access (CDMA) techniques allow high capacity and flexibility, continuous transmission requiring low-peak power requirements for the amplifiers, as well as some robustness against fading and time-dispersion effects associated with the multipath propagation. When employed in prefix assisted (PA) block transmission schemes combined with frequency-domain receiver implementations they become especially interesting for broadband wireless systems. In Frequency-Domain Multiuser Detection for CDMA Systems the use of PA block transmission is considered in the context of both DS (Direct Sequence) and MC (Multicarrier) CDMA schemes. The main goal is the study of frequency-domain multiuser detection techniques with iterative signal detection/decoding techniques, also in combination with estimation and cancelation of nonlinear distortion effects. The receiver structures are suitable to scenarios with high interference levels and strongly time-dispersive channels.

Author: Pieter van Rooyen
Publisher: Springer Science & Business Media
ISBN: 0306473259
Category : Technology & Engineering
Languages : en
Pages : 320

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Space-Time Processing for CDMA Mobile Communications is one of the first books to: bring together spatial/temporal channel models and analytic performance evaluation techniques; establish a link between smart antenna systems and advanced receiver design techniques; treat smart antennas specifically for UMTS-like communication systems, with applicable simulations and calculations; supply code with Matlab® GUI so readers can run or modify existing simulations or create new ones. The field of smart antenna technology or, more generally, space-time processing is rapidly becoming one of the most promising areas of mobile communications, especially regarding the development of the first practical third-generation mobile communication systems. The authors have addressed many of the most basic questions relating to the use of space-time processing in CDMA-based third-generation systems and have presented models for the integration of space-time processing, error correction coding, and multi-user detection techniques. Included is extensive background information on cellular systems, antenna array theory, smart antenna techniques, performance of basic space-time processors and advanced space-time processors. The book also includes an extensive simulation program written in Matlab®. The simulation code implements both the uplink and the downlink of a UMTS-like communication system. This provides multiple options for simulating system performance using a variety of channel models as well as receiver structures. Space-Time Processing for CDMA Mobile Communications will be an invaluable reference work for engineers and researchers, and a useful source for design engineers enabling them to understand the implications of adding space-time processing systems to CDMA-based communication systems.

Author: Vyacheslav Tuzlukov
Publisher:
ISBN:
Category : Technology
Languages : en
Pages :

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Signal Processing by Generalized Receiver in DS-CDMA Wireless Communications Systems.

Author: Marvin K. Simon
Publisher: John Wiley & Sons
ISBN: 0471715239
Category : Science
Languages : en
Pages : 1872

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The four short years since Digital Communication over Fading Channels became an instant classic have seen a virtual explosion of significant new work on the subject, both by the authors and by numerous researchers around the world. Foremost among these is a great deal of progress in the area of transmit diversity and space-time coding and the associated multiple input-multiple output (MIMO) channel. This new edition gathers these and other results, previously scattered throughout numerous publications, into a single convenient and informative volume. Like its predecessor, this Second Edition discusses in detail coherent and noncoherent communication systems as well as a large variety of fading channel models typical of communication links found in the real world. Coverage includes single- and multichannel reception and, in the case of the latter, a large variety of diversity types. The moment generating function (MGF)-based approach for performance analysis, introduced by the authors in the first edition and referred to in literally hundreds of publications, still represents the backbone of the book's presentation. Important features of this new edition include: * An all-new, comprehensive chapter on transmit diversity, space-time coding, and the MIMO channel, focusing on performance evaluation * Coverage of new and improved diversity schemes * Performance analyses of previously known schemes in new and different fading scenarios * A new chapter on the outage probability of cellular mobile radio systems * A new chapter on the capacity of fading channels * And much more Digital Communication over Fading Channels, Second Edition is an indispensable resource for graduate students, researchers investigating these systems, and practicing engineers responsible for evaluating their performance.

Author: Anat Katz
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Ryan A. Pacheco
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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QAM modulation of OFDM signals (OFDM-QAM) is a popular modulation scheme for linear communication systems because it achieves good spectral efficiency while simplifying the equalization process. This comes at the cost of requiring accurate synchronization methods in the receiver, highly stable oscillators (low phase-noise); and power inefficient transmission. This work addresses issues in these three areas. First, a new frame synchronization method is developed based on Bayesian changepoint principles. It has higher accuracy then current popular methods, can be implemented recursively, and has been tested with success on experimental data collected in a WLAN testbed. Second, phase-noise resistant communication is investigated by performing an accurate statistical analysis of self-heterodyne communication systems. The analysis can be used to accurately predict the bit error probability of such systems. Third, power efficient transmission using phase-modulation (OFDM-PM) is analyzed. The bandwidth, equivalent baseband model, and symbol error probability are investigated. We can now predict the performance of OFDM-PM systems; for a given spectral efficiency, when operating well into the threshold region of angle-demodulators., The semi-blind algorithms presented in this work attempt to improve interference suppression for a given number of training and information symbols by combining training-based and blind estimation techniques. We first derive the minimum number of training symbols the training-based least squares (LS) estimator requires for complete suppression of interference (in the noiseless case). This provides a benchmark which the semi-blind algorithms are compared against. Next, a framework for semi-blind iterative interference suppression is developed which is then used to enhance the LS estimator by adding the constant modulus and cyclostationary properties used in blind algorithms. Finally, a decision-aided (multistage) semi-blind algorithm that jointly processes the signals from all intra-cell users is presented. Simulation results indicate a significant improvement over training-based and blind estimation techniques. Application of this work is in the reverse-link of third generation short-burst asynchronous DS-CDMA systems subject to both ISI and MAI.

Author:
Publisher:
ISBN:
Category : Electrical engineering
Languages : en
Pages : 2240

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