Author: Youn Seok KimPublisher:
ISBN:
Category :
Languages : en
Pages : 106
Book Description
Spread Spectrum Based on Self Encoding Scheme in Slow Fading Channels
Author: Youn Seok KimSelf-encoded Spread Spectrum with Enhanced Diversity in Flat Fading Channels
Author: Liang ChiPublisher:
ISBN: 9781303049545
Category : Spread spectrum communications
Languages : en
Pages : 111
Book Description
In our dissertation, we focus on the SESS application with enhanced diversity in different transmission scenario such as multiple access, multichannel and multi-carrier techniques. Unlike the single user situation, there are two major sources of interference in the multiple access transmission system: one is multiple access interference (MAI) and the other is multipath interference (MI). The former occurs due to the cross correlation of CDMA codes and the latter is caused by the combined effect of out-of-phase autocorrelation and cross correlation of spreading codes used by the system in a multipath channel. The performance of the SESS based CDMA with two major impairing effects will be discussed in this dissertation.
A Comparison of Slow-frequency-hop and Direct-sequence Spread-spectrum Communications Over Frequency-selective Fading Channels
Author: John H. GassPerspectives in Spread Spectrum
Author: Amer A. HassanPublisher: Springer Science & Business Media
ISBN: 9780792382652
Category : Technology & Engineering
Languages : en
Pages : 178
Book Description
Perspectives in Spread Spectrum brings together studies and recent work on six exciting topics from the spread spectrum arts. The book gives a wide, collective view of trends, ideas, and techniques in the spread spectrum discipline, due to the authors' extensive work on spread spectrum techniques and applications from different vantage points. The inexorable march of electronics towards ever faster, ever smaller, and ever more powerful electronic and optical circuitry has wrought, and will continue to enable, profound changes in the spread spectrum arts, by allowing increasingly complex signalling waveforms and statistical tests to be implemented as the theory beyond spread spectrum continues to evolve. Perspectives in Spread Spectrum is divided into six chapters. The first chapter deals with sequence spreading design. There is not a single metric for design of spreading sequences; rather, the design is ideally tailored to the specific scenario of usage. This chapter delves into recent and very promising synthesis work. The second chapter deals with OFDM techniques. As channels become wider and trans-channel fading (or jamming) becomes frequency selective across the band, OFDM techniques may provide a powerful alternative design perspective. The third chapter is a generalization of the venerable Walsh functions. A new modulation scheme, Geometric Harmonic Modulation, GHM for short, is reviewed and characterized as a form of OFDM. From GHM, a further generalization of the Walsh functions is derived for non-binary signalling. The fourth chapter is concerned with some new and exciting results regarding the follower jammer paradigm. A counter-countermeasure technique is reviewed, notable for its counterintuitive characteristic which can be understood from a simple yet elegant game framework. The fifth chapter recounts some results pertaining to random coding for an optical spread spectrum link. The technique is based on laser speckle statistics and uses a coherent array of spatial light modulators at the transmitter but allows the receiver to be realized as a spatially distributed radiometric and therefore incoherent structure. The sixth and final chapter looks at an important and interesting application of spread spectrum to accurately locate a wideband, ‘bent pipe’, satellite transponder. It is, in a strong sense, an inverted GPS technique. Perspectives in Spread Spectrum serves as an excellent reference and source of ideas for further research, and may be used as a text for advanced courses on the topic.
Performance Analysis of Noncoherent Slow Frequency-hopped Spread-spectrum Communications Over Specular Multipath Fading Channels
Author: Kuo Tung ChiangFundamentals of Spread Spectrum Modulation
Author: Rodger E. ZiemerPublisher: Morgan & Claypool Publishers
ISBN: 1598292641
Category : Digital modulation
Languages : en
Pages : 87
Book Description
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].
A Study of Spread-spectrum Multiple-access Communications Over Fading Channels
Author: Evaggelos A. GeraniotisPublisher:
ISBN:
Category :
Languages : en
Pages : 322
Book Description
Direct Sequence Spread Spectrum Acquisition in Nonselective and Frequency Selective Fading Channels
Author: Essam A. SourourDigital Communication over Fading Channels
Author: Marvin K. SimonPublisher: John Wiley & Sons
ISBN: 0471715239
Category : Science
Languages : en
Pages : 936
Book Description
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.
Spread Spectrum Systems
Author: Robert Clyde DixonPublisher: Wiley-Interscience
ISBN:
Category : Science
Languages : en
Pages : 544
Book Description