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. 31, 1998
Filed:
Mar. 25, 1996
Hiroshi Hayashino, Takarazuka, JP;
Yasuo Harada, Kobe, JP;
Tomohiro Kimura, Kawachinagano, JP;
Yasuhiro Uno, Katano, JP;
Matsushita Electric Industrial Co., Ltd., Osaku-fu, JP;
Abstract
A pilot signal (a signal having known phase information and a prescribed length) is inserted at a prescribed time interval in a signal transmitted from a transmitting end to a receiving end. An arc tangent operation circuit (22) performs an operation for arc tangent of the pilot signal in a received signal to obtain a phase of the pilot signal. A phase error operation circuit (24) determines for a phase error between the known phase information previously held in a memory (23) and an output from the arc tangent operation circuit (22). A linear approximation circuit (25) takes an output from the phase difference operation circuit (24) as a linear function of time, and linear-approximates the output. A frequency error operation circuit (26) obtains for a frequency error from a slope of an output from the linear approximation circuit (25). In response to the obtained frequency error, control of an oscillation frequency of a variable frequency oscillation circuit allows rapid automatic frequency control with high accuracy.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile