Author:
Publisher:
ISBN:
Category : Communications, Military
Languages : en
Pages : 0
Book Description
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.
A Knowledge-Based Interference Rejection Scheme for Direct-Sequence Spread-Spectrum Systems
Author:
Publisher:
ISBN:
Category : Communications, Military
Languages : en
Pages : 0
Book Description
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.
Publisher:
ISBN:
Category : Communications, Military
Languages : en
Pages : 0
Book Description
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.
Narrowband Interference Rejection in Direct-sequence Spread-spectrum Systems Using Time Domain Adaptive Filters
Author: Cheryl L. Stutzmann
Publisher:
ISBN:
Category : Adaptive filters
Languages : en
Pages : 156
Book Description
Publisher:
ISBN:
Category : Adaptive filters
Languages : en
Pages : 156
Book Description
A Convex Projections Method for Improved Narrowband Interference Rejection in Direct Sequence Spread Spectrum Systems
Author: Krishna Rama Narayanan
Publisher:
ISBN:
Category :
Languages : en
Pages : 190
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 190
Book Description
Narrowband Interference Rejection Techniques in Direct Sequence Spread Spectrum Systems
Author: Ronald Athelstan Iltis
Publisher:
ISBN:
Category : Line receivers (Integrated circuits)
Languages : en
Pages : 328
Book Description
Publisher:
ISBN:
Category : Line receivers (Integrated circuits)
Languages : en
Pages : 328
Book Description
Interference Rejection Techniques to Aid Coarse Acquisition in Direct-sequence Spread-spectrum
Author: Lynn Denise Gottesman
Publisher:
ISBN:
Category :
Languages : en
Pages : 304
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 304
Book Description
Narrowband Interference Excision in Hybrid Frequency-hopping/direct-sequence Spread-spectrum Systems
Author: Carlos Jaime Chávez
Publisher:
ISBN:
Category :
Languages : en
Pages : 86
Book Description
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.
Publisher:
ISBN:
Category :
Languages : en
Pages : 86
Book Description
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.
IEEE International Conference on Personal Wireless Communications
Author:
Publisher:
ISBN:
Category : Mobile communication systems
Languages : en
Pages : 564
Book Description
Publisher:
ISBN:
Category : Mobile communication systems
Languages : en
Pages : 564
Book Description
Proceedings & Exhibition--future Access
Author:
Publisher:
ISBN:
Category : Mobile communication systems
Languages : en
Pages : 564
Book Description
Publisher:
ISBN:
Category : Mobile communication systems
Languages : en
Pages : 564
Book Description
Interference Effects in Direct Sequence Spread Spectrum Communications Systems
Author: Ward James Davies
Publisher:
ISBN:
Category : Electromagnetic interference
Languages : en
Pages : 366
Book Description
Publisher:
ISBN:
Category : Electromagnetic interference
Languages : en
Pages : 366
Book Description
Interference Nulling in Direct-sequence Spread-spectrum Systems Using a Main-beam Reference in the Delay Space
Author: Mark A. Jones
Publisher:
ISBN:
Category : Adaptive antennas
Languages : en
Pages : 244
Book Description
Publisher:
ISBN:
Category : Adaptive antennas
Languages : en
Pages : 244
Book Description