Download or read book Interference Rejection Techniques to Aid Coarse Acquisition in Direct sequence Spread spectrum written by Lynn Denise Gottesman and published by . This book was released on 1993 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Knowledge Based Interference Rejection Scheme for Direct Sequence Spread Spectrum Systems written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spread-spectrum signals are used widely in military and commercial communication systems due to their interference rejection capability and their lower probability of interception. In military applications the effects of intentional interference (jamming) are mitigated by the processing gain of the spread-spectrum system. In many spread-spectrum systems, processing gain alone is not sufficient to achieve satisfactory system performance and additional interference rejection techniques need to be employed. The interference suppression circuit is placed prior to the spectrum despreader with the goal of reducing the jammer/interferer energy to an adequately low level that can be handled by the system processing gain. We have presented a novel knowledge-based interference cancellation scheme for direct sequence spread-spectrum systems. This innovative approach utilizes: (1) IPUS, an expert system for the Integrated processing and Understanding of signals, to monitor the communication signal environment in order to determine the parameters of interfering signals within a pre-specified accuracy, and (2) Expert system rules to select from a library of preselected techniques, suitable interference rejection schemes based upon the knowledge obtained from monitoring the signal environment. The effectiveness of this novel interference rejection capability is demonstrated by considering a number of interference scenarios and using the software package SPW(copyright), a time-domain Signal Processing Worksystem.

Download or read book Narrowband Interference Rejection Techniques in Direct Sequence Spread Spectrum Systems written by Ronald Athelstan Iltis and published by . This book was released on 1984 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Narrowband Interference Excision in Hybrid Frequency hopping direct sequence Spread spectrum Systems written by Carlos Jaime Chávez and published by . This book was released on 2003 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: A direct-sequence spread-spectrum (DSSS) receiver is vulnerable to being desensitized by high-power narrowband signals within its wide received bandwidth. A solution to this problem is to detect the interfering signals and remove them from the received bandwidth in a process called narrowband interference excision. This can be achieved through a number of existing techniques. However, a hybrid system that utilizes both DSSS and frequency-hopping spread-spectrum (FHSS) techniques complicates the solution. This thesis investigates one technique for narrowband interference excision in the context of such a hybrid frequency-hopping/direct-sequence spread-spectrum (FH/DSSS) system. This technique is based on the discrete Fourier transform (DFT). An overview of DFT-based excision employing an overlap-and-add architecture is given. The critical properties of the window function used are examined, including windowing loss, excision lass, and interference rejection. Finally, the application of DFT-based excision in a hybrid FH/DSSS system is explored.

Download or read book Research in Progress written by and published by . This book was released on 1988 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Narrowband Interference Rejection in Direct sequence Spread spectrum Systems Using Time Domain Adaptive Filters written by Cheryl L. Stutzmann and published by . This book was released on 1998 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Narrowband Interference Suppression Techniques Using Decision Feedback Filtering in Direct Sequence Spread Spectrum Systems written by Katherine Jauregui Lovette and published by . This book was released on 1994 with total page 108 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 A Convex Projections Method for Improved Narrowband Interference Rejection in Direct Sequence Spread Spectrum Systems written by Krishna Rama Narayanan and published by . This book was released on 1994 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spread Spectrum Systems and Interference Rejection Techniques written by and published by . This book was released on 1979 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acquisition Techniques for Direct Sequence Spread Spectrum Packet Radio Systems written by Zhen-liang Shi and published by . This book was released on 1993 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acquisition of Direct Sequence Spread Spectrum with Modulation and Tone Jamming written by Eric William Siess and published by . This book was released on 1983 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rapid Acquisition Time Determination Techniques and Performance of Direct Sequence Spread Spectrum Signals written by Eric Conway MacCalla and published by . This book was released on 1979 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spread Spectrum Acquisition and Tracking written by Donald L. Schilling and published by . This book was released on 1984 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Spread Spectrum Systems and Interference Rejection Techniques written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Excision Techniques in Direct Sequence Spread Spectrum Communication Systems written by and published by . This book was released on 1990 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a comprehensive summary of a number of methods used in filtering narrowband jammers and interference out of direct sequence spread spectrum communication systems. The basic concept is presented first followed by a discussion of several analog techniques for interference suppression. Most of the emphasis is on digital adaptive methods, which rely on adaptive filtering algorithms. Many of these algorithms are highlighted. This is followed by a discussion on the research which has been conducted in digital excision over the past several years. Two cases based on the author's work are also presented. The first details the performance one can expect from the recursive least squares algorithm when the interferer is a stable tone. An analytical model, which predicts the bit error rate performance for the recursive algorithm under certain conditions, is derived. This model is compared to results obtained from computer simulation, the tracking and filtering capabilities of hte block and recursive least square algorithms when the interference is of the FM-type, i.e., a swept tone having a bandwidth which is approximately 20% of the chip rate. (Author).

Download or read book Advanced Techniques for Direct Sequence Spread Spectrum Acquisition written by Alem, Ahmad Waddah Kayyaly and published by . This book was released on 1977 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: