Download or read book Parallel Acquisition of Spreading Sequences in Direct sequence Spread spectrum Communication Systems written by Zhiyuan Yan and published by . This book was released on 1999 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parallel Acquisition of Spreading Sequences in Direct sequence Spread spectrum Communication Systems written by Meera Srinivasan and published by . This book was released on 1996 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parallel search schemes are presented for the acquisition of spreading sequences in chip-asynchronous direct-sequence spread-spectrum communication systems. In a parallel acquisition scheme, an estimate of the delay of a direct-sequence signal is made directly from a number of correlations of the received signal against different shifted versions of the spreading signal. Parallel schemes acquire the signal very quickly, but are more computationally intensive than serial schemes. In this thesis, we investigate several parallel strategies for the acquisition for general binary spreading sequences and develop suboptimal acquisition schemes that are easier to implement than the previously proposed optimal schemes. The techniques presented are attractive in that they approximate the optimal parallel schemes in terms of probability of successful acquisition, but are much easier to implement than the optimal schemes. The single-user phase-coherent situation is considered first. In this case, both carrier frequency and phase are known. We first discuss the optimal and maximum likelihood estimators for general binary spreading sequences and then present two new suboptimal schemes. One of these schemes is a small signal approximation of the optimal scheme, and it performs very well over a large range of signal-to-noise ratio. The other scheme is a hybrid of the optimal and maximum likelihood schemes, and is extremely simple. The hybrid scheme can be analyzed precisely in terms of its probability of unsuccessful acquisition. It is shown that this hybrid scheme has error probability decreasing exponentially with increasing SNR, and that this scheme is practically the simplest possible parallel scheme that has this property. Our result also proves an earlier conjecture that the optimal parallel estimator has error probability that decreases exponentially with increasing SNR. The same approach is used to devise simple acquisition schemes for the single-user noncoherent situation. A locally optimal estimator for low SNR is presented, along with two different noncoherent analogues of the coherent hybrid scheme. One of the noncoherent hybrid schemes is analyzed, and it is shown that this scheme also has exponentially decreasing error probability. This also proves that the error probability of the optimal noncoherent estimator decreases exponentially with increasing SNR. The problem of acquiring several direct-sequence signals in the absence of data modulation is also considered. The chip-synchronous situation is considered first and decorrelating methods are used to develop two near-far resistant strategies. One of these schemes estimates the signal delays in multiple stages, with each delay estimate depending on previous delay estimates, while the other scheme estimates the delays simultaneously and independently of each other. Schemes for the chip-asynchronous case are then developed by combining the coherent hybrid scheme for the single-user situation with the multistage decorrelating method. Monte Carlo simulation is used to obtain the error probabilities for the various schemes.

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 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 A Study of Binary Sequences for Direct Sequence Spread Spectrum Multiple Access Communication Systems written by 陳子健 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 Binary Sequences for Direct-sequence Spread-spectrum Multiple-access Communication Systems" by 陳子健, Chi-kin, John Baptist, Chan, 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_b3121276 Subjects: Spread spectrum communications

Download or read book Spread Spectrum Systems written by Robert Clyde Dixon and published by Wiley-Interscience. This book was released on 1976 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Bounds for a Simple Acquisition Scheme for Direct Sequence Spread Spectrum Communication Systems written by Eric Mathew Ollila and published by . This book was released on 1997 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parallel Acquisition in Code Division Multiple Access Spread Spectrum Systems written by Roland Reinhard Rick and published by . This book was released on 1995 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Acquisition of Direct Sequence Spread Spectrum Communication Systems written by Anthony Donald Demeri and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This Paper surveys different techniques of acquiring Direct Sequence Spread Spectrum Systems. It classifies different systems, indicates the strongpoints and weakness of each, along with some applications. One method, The Single Dwell Serial PN Acquisition System is then focused on in detail. The detail includes analysis of standard version, derivation of the mean time to acquire, the variance, the probability of detection and the probability of a false alarm. In the last section of the paper the analytical results of the Single Dwell Serial PN Acquisition System shall be confirmed by computer simulation.

Download or read book A Study of Binary Sequences for Direct sequence Spread spectrum Multiple access Communication Systems written by Chi-kin Chan (John Baptist) and published by . This book was released on 1996 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Performance of Direct sequence Spread Spectrum with Quaternary Complex Spreading Sequences written by Thomas G. Macdonald and published by . This book was released on 1998 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sequential Acquisition Schemes for Direct sequence Spread spectrum Systems written by Gurudutt S. Hosangadi and published by . This book was released on 1999 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Principles of Spread Spectrum Communication Systems Second Edition written by Don Torrieri and published by Springer Science & Business Media. This book was released on 2011-07-15 with total page 589 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise but lucid explanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles. Throughout the book, learning is facilitated by many new or streamlined derivations of the classical theory. Problems at the end of each chapter are intended to assist readers in consolidating their knowledge and to provide practice in analytical techniques. The choice of specific topics is tempered by the author’s judgment of their practical significance and interest to both researchers and system designers. The evolution of spread spectrum communication systems and the prominence of new mathematical methods in their design provided the motivation to undertake this new edition of the book. This edition is intended to enable readers to understand the current state-of-the-art in this field. More than 20 percent of the material in this edition is new, including a chapter on systems with iterative channel estimation, and the remainder of the material has been thoroughly revised.

Download or read book Wireless Communications written by Savo G. Glisic and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Time Division Multiple Access (TDMA), within a given time frame a particular user is allowed to transmit within a given time slot. This technique is used in most of the second-generation digital mobile communication systems. In Europe the system is known as GSM, in USA as DAMPS and in Japan as MPT. In Code Division Multiple Access (CDMA) every user is using a distinct code so that it can occupy the same frequency bandwidth at the same time with other users and still can be separated on the basis of low correlation between the codes. These systems like IS-95 in the USA are also developed and standardized within the second generation of the mobile communication systems. CDMA systems within a cellular network can provide higher capacity and for this reason they become more and more attractive. At this moment it seems that both TDMA and CDMA remain viable candidates for application in future systems. Wireless Communications: TDMA versus CDMA provides enough information for correct understanding of the arguments in favour of one or other multiple access technique. The final decision about which of the two techniques should be employed will depend not only on technical arguments but also on the amount of new investments needed and compatibility with previous systems and their infrastructures. Wireless Communications: TDMA versus CDMA comprises a collection of specially written contributions from the most prominent specialists in wireless communications in the world today and presents the major, up to date, issues in this field. The material is grouped into four chapters: Communication theory, covering coding and modulation, Wireless communications, Antenna & Propagation and Advanced Systems & Technology. The book describes clearly the issues and presents the information in such a way that informed decisions about third generation wireless systems can be taken. It is essential reading for all researchers, engineers and managers working in the field of Wireless Communications.

Download or read book Sequence Synchronisation in Chaos based Direct Sequence Spread Spectrum Communication Systems written by Ramin Vali and published by . This book was released on 2012 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an investigation into the modelling and performance of sequence synchronisation in Chaos-based Direct Sequence Spread Spectrum (CDS-SS) communication systems with the aims of identifying the existing gaps in research and suggesting a new and accurate modelling approach. The CDS-SS systems offer physical layer security without the need for a significant increase in computation or power requirements. This is significant when conventional encryption techniques cannot be used on secure communication systems because of their high power requirements as well as computational intensity. The main focus of this thesis is the problem of synchronising chaos-based spreading sequences. The modelling approaches previously used for chaos-based spreading codes do not take their non-binary nature into account and are not accurate as a result. This thesis extends the existing analysis in the literature to include CDS-SS synchronisation in presence of channel fading. Subsequently, an accurate approach is developed for modelling the synchronisation block of a CDS-SS system. This approach is based on the statistical description of chaos-based spreading codes cross- and auto-correlation functions and is termed chaos correlation statistics (CCS). To verify the validity of this approach, the acquisition stage of a CDS-SS synchronisation block is modelled using three scenarios: noise, fading and interleaving. It has been shown that the CCS method makes an accurate prediction of the acquisition phase performance for all three scenarios considered. The CCS method is also used to model a CDS-SS tracking loop statistically with high accuracy as verified by comparison with numerical analysis results. The effects of tracking loop errors and timing jitter on the probability of error have been derived for the same three scenarios mentioned above. These newly derived probability of error equations are verified by extensive simulation results. Overall it is concluded that sequence synchronisation for CDS-SS systems is possible and the CCS method is a suitable tool for accurate prediction of synchronisation performance in CDS-SS systems. Also, the CCS approach can be used in any scenario in which accurate modelling of the correlation function of non-binary spreading sequences is needed.

Download or read book Acquisition Time Performance Analysis of Single and Multiple Dwell Direct Sequence Spread Spectrum Communications Systems written by Michael R. Schuster and published by . This book was released on 1991 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Sequence Spread Spectrum in Communication System written by Ngoc Hoa Thach and published by . This book was released on 2004 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: