Interference Suppression for Spread Spectrum Signals Using Adaptive Beamforming and Adaptive Temporal Filter PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Interference Suppression for Spread Spectrum Signals Using Adaptive Beamforming and Adaptive Temporal Filter PDF full book. Access full book title Interference Suppression for Spread Spectrum Signals Using Adaptive Beamforming and Adaptive Temporal Filter by Wonjin Park. Download full books in PDF and EPUB format.
Author: Wonjin Park Publisher: ISBN: 9781423574040 Category : Adaptive filters Languages : en Pages : 99
Book Description
Interference and jamming signals are a serious concern in an operational military communication environment. This thesis examines the utility and performance of combining adaptive temporal filtering with adaptive spatial filtering (i.e. adaptive beamforming) to improve the signal-to-jammer ratio (SJR) in the presence of narrowband and wideband interference. Adaptive temporal filters are used for narrowband interference suppression while adaptive beamforming is used to suppress wideband interference signals. A procedure is presented for the design and implementation of a linear constraints minimum variance generalized sidelobe canceler (LCMV-GSC) beamformer. The adaptive beamformer processes the desired signal with unity gain while simultaneously and adaptively minimizing the output due to any undesired signal. Using the LCMV-GSC beamformer with a least mean squares (LMS) adaptive algorithm, it was shown that the tapped delay line (TDL) adaptive antenna array is more effective for the suppression of wideband jammer suppression than the linear array sensors (LAS) adaptive antenna array. Also a new technique for adaptive beamforming is presented which improves wideband interference suppression in a frequency-hopped environment. The output SJR improvement for the new technique compared to the conventional technique is as much as 15dB. Sometimes, multipath signals and jammers generated by a smart enemy are correlated with the desired signal which destroys the traditional beamformer's performance. After performing a spatial smoothing technique, adaptive beamforming can also be effective in suppressing the jamming signals that are highly correlated with the desired signal.
Author: Wonjin Park Publisher: ISBN: 9781423574040 Category : Adaptive filters Languages : en Pages : 99
Book Description
Interference and jamming signals are a serious concern in an operational military communication environment. This thesis examines the utility and performance of combining adaptive temporal filtering with adaptive spatial filtering (i.e. adaptive beamforming) to improve the signal-to-jammer ratio (SJR) in the presence of narrowband and wideband interference. Adaptive temporal filters are used for narrowband interference suppression while adaptive beamforming is used to suppress wideband interference signals. A procedure is presented for the design and implementation of a linear constraints minimum variance generalized sidelobe canceler (LCMV-GSC) beamformer. The adaptive beamformer processes the desired signal with unity gain while simultaneously and adaptively minimizing the output due to any undesired signal. Using the LCMV-GSC beamformer with a least mean squares (LMS) adaptive algorithm, it was shown that the tapped delay line (TDL) adaptive antenna array is more effective for the suppression of wideband jammer suppression than the linear array sensors (LAS) adaptive antenna array. Also a new technique for adaptive beamforming is presented which improves wideband interference suppression in a frequency-hopped environment. The output SJR improvement for the new technique compared to the conventional technique is as much as 15dB. Sometimes, multipath signals and jammers generated by a smart enemy are correlated with the desired signal which destroys the traditional beamformer's performance. After performing a spatial smoothing technique, adaptive beamforming can also be effective in suppressing the jamming signals that are highly correlated with the desired signal.
Author: Renbiao Wu Publisher: Springer ISBN: 9811055718 Category : Technology & Engineering Languages : en Pages : 289
Book Description
This book introduces readers to adaptive interference mitigation techniques based on multiple antennas for global navigation satellite systems (GNSS) in the time, domain, spatial and spatial-temporal domains. As the performance of GNSS can easily be impacted by various intentional and unintentional interferences, the book explores in detail various types of interference, including jamming , high dynamic jamming, spoofing, multipath and pulsed interference. It offers a valuable reference work for graduate students and engineers in the field of satellite navigation and signal processing.
Author: Gary J. Saulnier Publisher: ISBN: Category : Adaptive filters Languages : en Pages : 43
Book Description
Many methods have been proposed for suppressing interference in a direct sequence spread spectrum signal and a number of these utilize adaptive transversal suppression filters to remove a large portion of the interference prior to despreading. This report investigates the performance of predictive and two-sided adaptive filtering systems and presents a method to improve the performance of the predictive filter by compensating for the distortion introduced into the desired direct sequence signal during the adaptive filtering process. It is shown that the predictive filter acts as a pre-whitener and the two-sided filter acts as a power inverter. Additionally, the two-sided adaptive filter automatically performs the same function as the compensated predictive filter. The performance of the adaptive systems is also studied when there is multipath propagation and it is shown that the presence of multipath allows the filters to partially suppress the desired direct sequence signal, resulting in performance loss. A combination of simulation and analysis was used to perform this study. Simulations were performed using the Signal Processing Work System (SPW) from Alta Group of Cadence Design Systems, Inc.
Author: Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
This project is concerned with signal processing and coding techniques, which can improve the performance of spread-spectrum multiple-access systems. Specific topics investigated during the course of this project include: (1) Reduced-rank interference suppression; (2) Combined coding and interference suppression, (3) Joint transmitter-receiver optimization in the presence of multiple access interference; and (4) The effect of limited feedback on the performance of joint transmitter-receiver optimization schemes. The theory of large random matrices has been used to analyze the performance of both interference suppression and interference avoidance schemes. For example, we have used these techniques to analyze the performance of adaptive reduced- and full-rank least squares filtering for interference suppression with limited training. This analysis shows the effects of algorithm parameters, which determine the initialization and data windowing, along with system load and noise level. Other contributions include optimization of the ratio of pilot-to-data power and code rate with adaptive linear interference suppression, and signature optimization for combined interference avoidance and pre-equalization of multi-path. Transmitter optimization with limited feedback has also been considered, and bounds on the achievable performance as a function of feedback bits per dimension have been obtained. This project has resulted in a patent application for an adaptive reduced-rank filter, a paper award (for work on reduced-rank filtering), and numerous journal and conference publications on the preceding topics.
Author: Gary J. Saulnier Publisher: ISBN: Category : Adaptive filters Languages : en Pages : 0
Book Description
Many methods have been proposed for suppressing interference in a direct sequence spread spectrum signal and a number of these utilize adaptive transversal suppression filters to remove a large portion of the interference prior to despreading. This report investigates the performance of predictive and two-sided adaptive filtering systems and presents a method to improve the performance of the predictive filter by compensating for the distortion introduced into the desired direct sequence signal during the adaptive filtering process. It is shown that the predictive filter acts as a pre-whitener and the two-sided filter acts as a power inverter. Additionally, the two-sided adaptive filter automatically performs the same function as the compensated predictive filter. The performance of the adaptive systems is also studied when there is multipath propagation and it is shown that the presence of multipath allows the filters to partially suppress the desired direct sequence signal, resulting in performance loss. A combination of simulation and analysis was used to perform this study. Simulations were performed using the Signal Processing Work System (SPW) from Alta Group of Cadence Design Systems, Inc.
Author: Rabindra N. Ghose Publisher: Institute of Electrical & Electronics Engineers(IEEE) ISBN: Category : Science Languages : en Pages : 296
Book Description
This book presents means and technologies to reduce interference that affect the reception of radio, television and radar signals. Various alternatives to mitigate interference, created intentionally or inadvertently, and their underlying theories are discussed. Key topics include adaptive interference cancellation, interference rejection by a fixed or adaptive array, adaptive separation of signals, and innovative applications of closed loop cancellation technology in acoustics, direction finding and in instrumentation.
Author: Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Based on the theory of locally optimum detection we identified a spread-spectrum receiver architecture that consists of an adaptive non-linear chip-level pre-processor followed by an adaptive linear filter post-processor. The non-linear front-end protects against impulsive, non-Gaussian disturbance. The adaptive linear filter post-processor suppresses unknown highly correlated spread-spectrum (SS) interference. To achieve adaptive, rapid, and effective SS interference suppression from a small number of input observations, we defined a new class of linear filters that we called Auxiliary-Vector (AV) filters. We view this development as a breakthrough in the field of adaptive signal processing theory. When the input autocorrelation matrix is unknown and estimated from a limited set of input data (as in all real-life adaptive signal processing applications), Auxiliary-Vector filters are shown to outperform all other filter estimator means in the literature. We addressed successfully the critical problem of determining an automated, theoretically derived, rule for the selection of the best number of auxiliary vectors (AV's) for a given data record of input observations. We anticipate that this development will attract a great deal of interest in the Auxiliary-Vector filtering technique. Based on the principles of AV-filtering we proposed and analyzed theoretically structures that are self-synchronized in the sense that adaptive synchronization and demodulation are viewed and treated as an integrated receiver operation. As a major application, we addressed the problem of navigation data demodulation by an adaptive jam-resistant GPS receiver that utilizes a bank of linear-tap-delay filters and employs antenna-array reception (one space-time.
Author: Wonjin Park
Author: Wonjin Park
Author: Renbiao Wu
Author: Gary J. Saulnier
Author: 
Author: Gary J. Saulnier
Author: Katherine Jauregui Lovette
Author: Rabindra N. Ghose
Author: 
Author: Young Kil Kwag
Author: Calvin J. Grant