The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 07, 2003
Filed:
Sep. 01, 1999
Russell H. Lambert, Fountain Valley, CA (US);
Peter J. Hadinger, Oakton, VA (US);
Denes L. Zsolnay, Rolling Hills Estates, CA (US);
Bruce W. Evans, Redondo Beach, CA (US);
Shi-Ping Hsu, Pasadena, CA (US);
Gerard Roccanova, Huntington Beach, CA (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
A method ( ) and apparatus ( ) for encoding and decoding data in a signal using notch depth modulation. The method ( ) of data to be encoded in the signal. The method then notch filters ( ) the signal according to the frequency notch representation of the data. The apparatus ( ) for encoding data comprises an digitizer ( ) to digitize the signal. A code former ( ) provides the data to be encoded in the signal. A notch filter ( ) notch filters the signal according to the data. Decoding the data converts the signal into a frequency domain representation ( ) and determines the notch spectral content ( ) of the signal at selected notch frequencies. The method ( ) establishes notch thresholds ( ) at each of the selected notch frequencies, then decodes the data ( ) from the signal by comparing the notch spectral content to the notch thresholds.