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:
Jun. 08, 1993
Filed:
Dec. 02, 1991
Josef Osterweil, Rockville, MD (US);
GTE Government Systems Corporation, Waltham, MA (US);
Abstract
Method and apparatus for changing the bit rate of a digitized analog signal stream from a first bit rate to a second bit rate. A first sequence generator provides a digital predictor sequence clocked at the first bit rate. A combiner has an output providing a combined digital stream at the first bit rate, combining the digital predictor sequence at the first bit rate and the digital analog signal stream at the first bit rate. An adaptive processor has its input coupled to at the output of the signal combiner. The adaptive processor has variable weights which are responsive to an error signal, an output providing a processed combined digital stream having a bit rate responsive to the weights, and an error signal input port. A second sequence generator provides the same digital predictor sequence, but clocked at the second bit rate. An error detector, coupled to output of the adaptive processor and the digital predictor sequence clocked at the second bit rate, provides an error signal representing the difference between the bit rate of the processed digital sequence and the digital predictor sequence clocked at the second bit rate. The error signal is coupled to the error signal port of the adaptive processor is used to adjust the weights of the adaptive processor to minimize the error signal and therefore minimize the effects of the difference between the bit rate of the processed combined digital stream and the second bit rate. The apparatus strips the digital predictor sequence from the processed combined digital stream. The combined digital stream may be sent through a satellite communication system, allowing correction of any doppler frequency shifting due to a drifting satellite and interfaces to systems with poor or unknown timing standards.