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:
Nov. 25, 2008
Filed:
Aug. 15, 2003
Applicant:
Hoang Nhu, Irvine, CA (US);
Inventor:
Hoang Nhu, Irvine, CA (US);
Assignee:
Broadcom Corporation, Irvine, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04H 20/47 (2008.01); H04H 20/88 (2008.01); H04H 40/36 (2008.01); H04H 20/48 (2008.01); H04H 40/54 (2008.01); H04J 15/00 (2006.01); H04R 5/00 (2006.01); H04N 7/00 (2006.01); H04N 5/60 (2006.01);
U.S. Cl.
CPC ...
Abstract
A Japanese BTSC audio broadcast signal has three modes of transmission: mono, stereo, or dual mono. The control channel centering at 3.5 fH is one of the three channels in the J-BTSC signal, and contains information to indicate to the decoder which one of the three modes the audio transmission is in. The present invention uses a bandpass filter directly in the AM band, followed by envelope filtering and a decision circuit. Therefore, the need for AM demodulation and AM carrier detection is eliminated.