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. 02, 1989
Filed:
Sep. 08, 1987
Yoshizo Shibano, Osaka, JP;
Sumitomo Electric Industries Ltd., Osaka, JP;
Abstract
A demodulator is disclosed for a PSK-modulated transmission signal in which the time average value of the frequencies thereof ar equal to the carrier frequency. A mixer receives and mixes the PSK-modulated transmission signal with a signal from a local variable frequency oscillator and the output thereof is converted to a square wave which is used to reconstruct the original digital modulation data. A pulse counter receives and counts the square wave signal for every period of time which is n times a time slot of a digital signal and a subtractor provides a difference between the count value from the pulse counter and a reference count number. The subtractor output is converted to an analog signal which controls the local oscillator frequency.