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. 28, 2002
Filed:
Aug. 16, 1999
Hidenori Maruyama, Tokyo, JP;
NEC Corporation, , JP;
Abstract
An automatic frequency control circuit includes a phase difference detection circuit, average value calculation circuit, weighting circuit, and phase correction circuit. The phase difference detection circuit obtains the phase difference between pattern signals per period on the basis of a quadrature-demodulated pattern signal component and a pattern signal component one period before the quadrature-demodulated pattern signal component. The average value calculation circuit calculates the average value of first phase differences between the pattern signals repetitively output from the phase difference detection circuit, thereby obtaining a second phase difference in units of symbols in the current burst. The weighting circuit weights the second phase difference from the average value detection circuit and a third phase difference up to the previous burst, thereby obtaining a fourth phase difference up to the current burst. The phase correction circuit corrects a demodulated received signal on the basis of the fourth phase difference from the weighting circuit.