Download or read book Multiple Access Interference Characterization for Direct Sequence Spread Spectrum Communications Using Chip Waveform Shaping written by Matthew G. Glen and published by . This book was released on 2004-03-01 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research characterizes MAI effects on DS/SSMA system performance through simulation in Matlab , and explores the impact of multiple access code selection, chip waveform shaping, and multiple access code length on BER for both synchronous and asynchronous multiple access networks. In addition, the simulated DS/SSMA model permits rapid research into the effects of additional factors on BER. Prior to experimental testing, model validation is conducted through single user trials and by comparison with existing research for similar system designs. For synchronous and asynchronous networks, Gold coding improves BER by 7.5 and 4.0 dB, respectively, relative to aperiodic random spreading codes. Synchronous network results show that chip waveform shaping provides no significant BER improvement for the Blackman or Lanczos shapes. However, asynchronous network results show a potential BER improvement for Blackman and Lanczos shapes. Increasing code length from 31 to 511 resulted in a 7.5 dB BER improvement. Collectively, these results directly relate changes in BER to waveform cross-correlation statistics.
Download or read book Chip Waveform Selection in Offset quaternary Direct sequence Spread spectrum Multiple access Communications written by James Stanley Lehnert and published by . This book was released on 1981 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: An offset-quaternary direct-sequence spread-spectrum multiple-access communication system is analyzed. This analysis considers the effect of the choice of chip waveforms on the bandwidth which the system utilizes, the signal-to-noise ratio at each user's receiver, and the constant-envelope character of the transmitted signals. (Author).
Download or read book Perspectives in Spread Spectrum written by Amer A. Hassan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Interference Characterization and Suppression for Multiuser Direct sequence Spread spectrum System written by Mingxi Fan and published by . This book was released on 2002 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis we investigate efficient modulation and detection techniques for the uplink (i.e. transmission from mobile to base station) of a DS-CDMA network. Specifically, the thesis contains three parts. In the first part, we focus on the mobile transmitter. In particular, we evaluate and compare the spectral efficiency of two promising variable rate DS-CDMA transmission techniques, multicode (MCD) and variable-spreading-gain (VSG), under the presence of multiple-access (user-to-user) interferences (MAI) and multipath interferences. The uniqueness of our study is that in bit-error-rate evaluation, instead of approximating the interference as Gaussian noise (which has been done in most of the previous studies), we incorporate both power and distribution of interferences into consideration. We show where the Gaussian assumption may give misleading answers and how our results in these cases are different from those obtained in the past. In part two and three of the thesis, we focus on the base station receiver. Specifically, we present effective joint detection techniques that have good performance-complexity tradeoff. Part two of the thesis introduces a class of novel multistage parallel interference cancellation algorithms based on stage-by-stage minimum mean-squared error (MMSE) optimization. We show that this scheme is capable of achieving significantly better performance than other algorithms with similar complexity. Part three of the thesis presents a low-complexity dual-mode multiuser detector that dynamically switches its detection mode between the matched-filter receiver and the decorrelator. We show that this detector is capable of achieving the performance of a decorrelator but with significant savings in processing power and complexity.
Download or read book An Analysis of Modified Direct Sequence Spread spectrum Techniques Applied to Multiple Access Communications written by John William Porter and published by . This book was released on 1984 with total page 564 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 Adaptive Direct sequence Spread spectrum Communications written by Rahul Singh and published by . This book was released on 1996 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Narrowband and Multiple Access Interference Suppression for Direct Sequence Spread Spectrum Communication Receivers written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents research results focused on the mitigation of both narrowband and multiple access interference in direct sequence spread spectrum communication systems. Both linear and nonlinear adaptive algorithmic approaches are developed and reported. Specific attention has been paid to making the algorithmic practicable. In addition to the algorithmic development, a software simulation for a code division multiple access system is developed using a commercially available programming environment.
Download or read book Direct sequence Spread spectrum Multiple Access DS SSMA Communications Using Complex Signature Sequences written by Fatih M. Ozluturk and published by . This book was released on 1990 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multiple Access Interference Rejection Technique Using Weighted Despreading Functions for Direct Sequence Code Division Multiple Access Communications written by Yuejin Huang and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "A Multiple Access Interference Rejection Technique Using Weighted Despreading Functions for Direct-sequence Code Division Multiple Access Communications" by 黃耀進, Yuejin, Huang, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3123707 Subjects: Wireless communication systems Code division multiple access Spread spectrum communications
Download or read book Multi Carrier Spread Spectrum written by Khaled Fazel and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: The benefits and success of multi-carrier (MC) modulation on one side and the flexibility offered by the spread spectrum (SS) technique on the other side have motivated many researchers to investigate the combination of both techniques since 1993. This combination known as multi-carrier spread spectrum (MC-SS) benefits from the advantages of both systems and offers high flexibility, high spectral efficiency, simple detection strategies, narrow-band interference rejection capability, etc. The basic principle of this combination is straightforward: The spreading is performed as direct sequence spread spectrum (DS-SS) but instead of transmitting the chips over a single carrier, several sub-carriers are employed. The MC modulation and demodulation can easily be realized in the digital domain by performing IFFT and FFT operations. The separation of the users' signals can be performed in the code domain. MC-SS systems can perform the spreading in frequency direction, which allows for simple signal detection strategies. Since 1993, MC-SS has been deeply studied and new alternative solutions have been proposed. Meanwhile, deep system analysis and comparison with DS-CDMA have been performed that show the superiority of MC-CDMA.
Download or read book Spread Spectrum Techniques written by Robert C. Dixon and published by . This book was released on 1976-11-01 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Signal to noise plus interference Ratio Estimation and Statistics for Direct Sequence Spread Spectrum Code Division Multiple Access Communications written by Amit Gupta and published by . This book was released on 2004 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interference Effects in Direct Sequence Spread Spectrum Communications Systems written by Ward James Davies and published by . This book was released on 1989 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Direct Sequence Spread Spectrum Multiple Access Communications Over Multipath Rayleigh Fading Channels written by 葉冠華 and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "A Study of Direct-sequence Spread-spectrum Multiple-access Communications Over Multipath Rayleigh Fading Channels" by 葉冠華, Kun-wah, Yip, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3123454 Subjects: Spread spectrum communications
