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:
Jan. 13, 2004
Filed:
Aug. 09, 2000
Hisakazu Katoh, Tokyo, JP;
Akinori Hashimoto, Tokyo, JP;
Kenichi Shiraishi, Yokohama, JP;
Akihiro Horii, Zama, JP;
Shoji Matsuda, Machida, JP;
Kabushiki Kaisha Kenwood, Tokyo, JP;
Abstract
A hierarchical transmission digital demodulator capable of stable sync capture and stable demodulation through setting of a demodulation operation in accordance with a reception C/N value. A CNR measuring circuit receives a demodulation output from an arithmetic circuit and measures a reception C/N value. During a period until sync is captured, a carrier is reproduced in accordance with the demodulation output that a modulated wave in a header section and a modulated wave of burst symbol signal. After sync is captured, at an intermediate C/N value the carrier is reproduced in accordance with the demodulation output of the header section, burst symbol signal and QPSK signal and in accordance with output from a logical gate circuit, and at high and low C/N values the carrier is reproduced by setting high a carrier reproduction loop gain of a gain control circuit in accordance with a signal from the logical gate circuit.