Pulse or digital communications – Spread spectrum – Direct sequence
Reexamination Certificate
2011-01-11
2011-01-11
Burd, Kevin M (Department: 2611)
Pulse or digital communications
Spread spectrum
Direct sequence
C375S136000
Reexamination Certificate
active
07869487
ABSTRACT:
A quadrature multi-frequency ranging system applied to DSSS multipath mitigation problems is described. The QMFR techniques include taking the time-of-arrival measurements on the received signal at a time when the multipath component is at a 90 degree angle to the direct path. Further, the preferred embodiment of the present invention recognizes that when a signal is transmitted at a series of frequencies, and the spread of these frequencies is sufficient, a quadrature or near quadrature condition can be forced to occur, at which the TOA estimation gives the highest certainty of measurement.
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Gilmour Paul A.
McCrady Dennis D.
Burd Kevin M
Davidson Berquist Jackson & Gowdey LLP
ITT Manufacturing Enterprises Inc.
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