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:
Oct. 28, 2003
Filed:
May. 18, 2000
Hisakazu Katoh, Tokyo, JP;
Akinori Hashimoto, Tokyo, JP;
Tomohiro Saito, Tokyo, JP;
Fumiaki Minematsu, Tokyo, JP;
Kenichi Shiraishi, Yokohama, JP;
Akihiro Horii, Zama, JP;
Shoji Matsuda, Machida, JP;
Soichi Shinjo, Machida, JP;
Kabushiki Kaisha Kenwood, Tokyo, JP;
Abstract
A digital demodulator that eliminates the need for an absolute phase circuit is provided. In a digital demodulator for a digital broadcasting receiver that receives digital time-division multiplexed signals of different types of modulation, the demodulated baseband signal is selectively inverted by an inverter ( ) according to an inversion command signal “0” or “1” that is output from an inversion decision circuit ( ) depending on a BPSK signal of a known pattern. A phase error detector ( ) for carrier reproduction determines the phase error voltage based on the phase difference between the absolute phase and the phase of the signal point of the demodulated baseband signal output from the inverter ( ). The phase error voltage is passed through a carrier filter ( ), including a low-pass filter, to control the carrier frequency so that carrier reproduction can be carried out with the phase at the signal point being coincident with the point of phase convergence.