Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2007-11-06
2007-11-06
Odom, Curtis (Department: 2611)
Pulse or digital communications
Receivers
Interference or noise reduction
C375S346000, C701S213000, C701S214000, C701S215000
Reexamination Certificate
active
11000827
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.
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Johnston Ivan L.
Van Wechel Robert J.
Knobbe Martens Olson & Bear LLP
L-3 Communications Corporation
Odom Curtis
LandOfFree
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