Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2005-10-04
2005-10-04
Chin, Stephen (Department: 2634)
Pulse or digital communications
Receivers
Interference or noise reduction
Reexamination Certificate
active
06952460
ABSTRACT:
A system for efficiently filtering interfering signals in a front end of a GPS receiver is disclosed. Such interfering signals can emanate from friendly, as well as unfriendly, sources. One embodiment includes a GPS receiver with a space-time adaptive processing (STAP) filter. At least a portion of the interfering signals are removed by applying weights to the inputs. One embodiment adaptively calculates and applies the weights by Fourier Transform convolution and Fourier Transform correlation. The Fourier Transform can be computed via a Fast Fourier Transform (FFT). This approach advantageously reduces computational complexity to practical levels. Another embodiment utilizes redundancy in the covariance matrix to further reduce computational complexity. In another embodiment, an improved FFT and an improved Inverse FFT further reduce computational complexity and improve speed. Advantageously, embodiments can efficiently null a relatively large number of jammers at a relatively low cost and with relatively low operating power.
REFERENCES:
patent: 4186349 (1980-01-01), Gordy et al.
patent: 5610991 (1997-03-01), Janse
patent: 6167417 (2000-12-01), Parra et al.
Nicholson, et al., “Computer Simulation of Digital Beam Forming Adaptive Antennae for GPS Interference Mitigation” [online] Presented at ION Navigation 2000 Conference; Long Beach, CA, Jan. 21-23, 1998, Retrieved from the Internet: <URL:http://www.mayflowercom.com/computersim.htm>. Retrieved on Sep. 19, 2002.
Upton, et al., “Commercial-Off-The-Shelf (COTS) GPS Interference Canceller and Test Results” [online] Presented at ION Navigation 2000 Conference; Long Beach, CA, Jan. 21-23, 1998, Retrieved from the Internet: <URL:http//www/mayflowercom.com/cots.htm>. Retrieved on Sep. 19, 2002.
Nicolaides, et al., “Digital Beam/Null Forming Adaptive Antenna for GPS Anti-Jam Application” [online] Paper to be presented at the 23rdJoint Services Data Exchange Meeting, Orlando, FL, Nov. 18-21, 1996 <URL:http://www.mayflowercom.com/digitalbeam.htm>. Retrieved on Sep. 19, 2002.
Lawrence R. Rabiner and Bernard Gold, “Theory and Application of Digital Signal Processing” Prentice-Hall, 1975 ISBN 0-13-914101-4, pp. 604-609.
Johnston Ivan L.
Van Wechel Robert J.
Chin Stephen
Knobbe Martens Olson & Bear LLP
L-3 Communications Corporation
Odom Curtis
LandOfFree
Efficient space-time adaptive processing (STAP) filter for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Efficient space-time adaptive processing (STAP) filter for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient space-time adaptive processing (STAP) filter for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3457062