Author: Essam A. SourourPublisher:
ISBN:
Category :
Languages : en
Pages : 240
Book Description
Direct Sequence Spread Spectrum Acquisition in Nonselective and Frequency Selective Fading Channels
Author: Essam A. SourourA 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: 1461555310
Category : Technology & Engineering
Languages : en
Pages : 170
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.
Parallel Acquisition in Code Division Multiple Access Spread Spectrum Systems
Author: Roland Reinhard RickPublisher:
ISBN:
Category :
Languages : en
Pages : 292
Book Description
The Performance of Direct-sequence Spread-spectrum Communications with Selective Fading Channels and Rake Reception
Author: Daniel Lee NoneakerPublisher:
ISBN:
Category : Spread spectrum communications
Languages : en
Pages : 118
Book Description
Spread Spectrum Communications
Author: Marvin K. SimonPublisher:
ISBN: 9780881750157
Category : Spread spectrum communications
Languages : en
Pages : 456
Book Description
Performance Analysis of Direct-sequence Spread-spectrum Multiple-access Communication Via Fading Channels
Author: David Edward BorthPublisher:
ISBN:
Category :
Languages : en
Pages : 366
Book Description
The performance of biphase direct-sequence spread-spectrum multiple-access (SSMA) communication for a general class of fading channels is investigated. The channels considered are those for which the channel output consists of a strong stable specular signal plus a faded version of this signal. Such channels are the result of a transmission medium which gives rise to a major stable communication path and a number of additional weaker communication paths. The fading channel is modeled as a general is modeled as a general wide-sense-stationary uncorrelated-scattering (WSSUS) channel -- a model which is general enough to exhibit both time and frequency selectivity and to impose no restrictions on the fading rate. A discussion of the important parameters of the WSSUS channel is given and two important classes of WSSUS channels are developed from the general fading channel model; time-selective fading channels and frequency-selective fading channels. In analyzing the performance of direct-sequence SSMA communications via fading channels two measures of system performance that are considered are average signal-to-noise ratio at the receiver output and the average probability of error. (Author).
Spread Spectrum, Acquisition and Tracking
Author: Donald L. SchillingPublisher:
ISBN:
Category :
Languages : en
Pages : 58
Book Description
This report discusses the following subjects: A New Rapid Acquisition Technique for Direct Sequence Spread Spectrum Communications. The rapid acquisition technique described here can be used in direct sequence spread spectrum systems. The technique employs a double threshold which defines when a decision can be made. These thresholds change at each examination instant. Using this technique a significant reduction in the acquisition time of a direct sequence spread spectrum signal is obtained. A New Double Threshold Acquisition Scheme Applied to the Fading Channel in Frequency Hopping Spread Spectrum.
Scrambling Techniques for CDMA Communications
Author: Byeong Gi LeePublisher: Springer Science & Business Media
ISBN: 0306473216
Category : Technology & Engineering
Languages : en
Pages : 350
Book Description
This invaluable text addresses spreading, scrambling and synchronization techniques for use in inter-cell synchronous and asynchronous CDMA systems, including the IMT-2000. It provides fundamental background material and introduces novel acquisition techniques that enable rapid and robust acquisition of inter-cell synchronous and asynchronous IMT-2000 CDMA systems.
Models for Frequency-hopped Spread-spectrum Communications Over Fading Channels
Author: Catherine Marie KellerPublisher:
ISBN:
Category :
Languages : en
Pages : 102
Book Description
The system consisting of the series connection of a frequency-hopper, channel, and frequency-dehopper is modeled as a fading channel. The effect of a detuning factor between the hopping patterns of the hopper and dehopper is investigated. Both slow-frequency-hopped and fast-frequency-hopped systems are studied for cases when the fading channel is nonselective and selective. The ability of the frequency-hopped system to overcome frequency-selective fading is considered. Limits are found on the spacing between frequency slots in order that the fading in different slots is independent. (Author).