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:
Mar. 16, 1982
Filed:
Apr. 28, 1980
William N Waggener, Sarasota, FL (US);
Sangamo Weston, Inc., Norcross, GA (US);
Abstract
An adaptive differential phase shift keyed (PSK) signal demodulator which optimally tracks changes in the symbol rate of the signal. An input signal is delayed by one symbol period by passing the signal through a charge coupled device (CCD) clocked by pulses phase locked to the symbol rate (F.sub.br) by a phase locked loop, the phase locked loop also outputting clock pulses at the symbol rate to strobe a symbol decision circuit. The CCD has L stages and is clocked at a rate L.multidot.F.sub.br. As the phase locked loop tracks changes in the symbol rate, the clock pulses are varied in rate so that the CCD delay is adaptively optimized for a given symbol rate. Digital tuning is provided by an adjustable divider circuit coupling the voltage controlled oscillator of the phase locked loop to the CCD, so that by digitally selecting the division ratio the demodulator is tuned to a different symbol rate.