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:
May. 01, 1990
Filed:
Jun. 28, 1989
David C Nicholas, Cedar Rapids, IA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
A method is disclosed for demodulating binary differential phase shift keyed signals in the presence of carrier frequency uncertainties. In phase modulation, a data signal is impressed on a carrier frequency to produce a modulated signal. The modulated signal and a corresponding quadrature signal are input to a split delay line, wherein each half of the delay line provides a delay of one-half the data signal bit period. The modulated and the delayed signals are input to a summing junction to provide a combined output independent of the carrier frequency. Thus, the method of demodulation is insensitive to Doppler shifts and other carrier frequency offsets.