Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2005-03-21
2009-06-09
Torres, Juan A (Department: 2611)
Pulse or digital communications
Receivers
Interference or noise reduction
C340S426190, C340S539130, C342S357490, C342S357490, C342S357490, C701S213000
Reexamination Certificate
active
07545894
ABSTRACT:
A method acquires a location system signal that includes second data signals superimposed on the first data signals. The method includes iterating Doppler frequency offset values and time offsets to generate error signals, each representing a difference between summed consecutive correlation values and a corresponding estimated ideal value. Each error signal corresponds to a different time offset and an associated time period. The second data signal has a bit edge that occurs during the time period of each of the sums of consecutive correlation values. The presence of a bit edge during an associated time period increases the error signal. A measure of the minimum error is used to identify a time offset value that is used to develop a first determined Doppler frequency offset. A Kalman filter refines the first determined Doppler frequency offset.
REFERENCES:
patent: 2003/0201934 (2003-10-01), Asher et al.
patent: 2006/0055596 (2006-03-01), Bryant et al.
Ziedan, “Unaided Acquisition of Weak GPS Signals Using Circular Correlation or Double-Block Zero Padding,” in Proc. IEEE-Plans 2004, Apr. 26-29, 2004.
Little, “GPS disciplined rubidium oscillator” European Frequency and Time Forum, 1996. EFTF 96., Tenth (IEE Conf. Publ. 418) Mar. 5-7, 1996 pp. 105-110.
Schneider, “A Kalman filter for an integrated Doppler/GPS navigation system”, Position Location and Navigation Symposium, 1988, “Navigation into the 21st Century”, IEEE Plans '88, IEEE Nov. 29-Dec. 2, 1988 pp. 408-415.
Garrison James L.
Ziedan Nesreen I.
Maginot Moore & Beck
Purdue Research Foundation
Torres Juan A
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