Inverse fast fourier transform (IFFT) with overlap and add

Details Inverse fast fourier transform (IFFT) with overlap and add Inverse fast fourier transform (IFFT) with overlap and add

2007-03-27

2007-03-27

Patel, Jay K. (Department: 2611)

Pulse or digital communications

Receivers

Interference or noise reduction

C708S403000, C708S404000, C708S405000, C708S406000, C708S408000, C708S409000

Reexamination Certificate

active

11000861

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: 4471357 (1984-09-01), Wu et al.
patent: 4559605 (1985-12-01), Norsworthy
patent: 4689762 (1987-08-01), Thibodeau, Jr.
patent: 4940977 (1990-07-01), Mandell
patent: 5293330 (1994-03-01), Sayegh
patent: 5299144 (1994-03-01), Bartkowiak et al.
patent: 5610991 (1997-03-01), Janse
patent: 5825327 (1998-10-01), Krasner
patent: 6098088 (2000-08-01), He et al.
patent: 6161130 (2000-12-01), Horvitz et al.
patent: 6167417 (2000-12-01), Parra et al.
patent: 6292592 (2001-09-01), Braunreiter et al.
patent: 6404806 (2002-06-01), Ginesi et al.
patent: 6480139 (2002-11-01), Hoctor
patent: 6587501 (2003-07-01), Yu
patent: 6650714 (2003-11-01), Dogan et al.
patent: 6735427 (2004-05-01), Higbie
patent: 6745352 (2004-06-01), Cheng
patent: 6778591 (2004-08-01), Sato
patent: 6801589 (2004-10-01), Dogan
patent: 6885338 (2005-04-01), Gaus et al.
patent: 6898612 (2005-05-01), Parra et al.
patent: 2002/0168035 (2002-11-01), Carlson et al.
“Interim Guidelines for Examination of Patent Applications for Patent Subject Matter Eligibility”.
Nicholson, et al., “Computer Simulation of Digital Beam Forming Adaptive Antennas 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 23rd Joint 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.

Affiliated with

Also associated with

Rating

Inverse fast fourier transform (IFFT) with overlap and add does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Inverse fast fourier transform (IFFT) with overlap and add, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Inverse fast fourier transform (IFFT) with overlap and add will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3784495