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. 12, 2012
Filed:
Aug. 19, 2008
Moto Yamada, Kyoto, JP;
Moto Yamada, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
A carrier offset detection circuit is offered, which is provided to a demodulation circuit which demodulates a received signal subjected to FSK (Frequency Shift Keying) modulation, and which detects the offset of the carrier frequency between the transmitting side and the receiving side. A zero-crossing detection unit receives a digital base band signal indicating the level of the frequency shift (frequency deviation) of the received signal using the carrier frequency on the receiving side as a reference frequency, and detects a zero-crossing point of the base band signal and a base band signal obtained by delaying the former base band signal by one symbol, which occurs in a preamble period. A carrier offset detection circuit sets the offset value of the carrier frequency to the value of the base band signal at a timing of the zero-crossing point thus detected.