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:
Jul. 07, 1987
Filed:
Apr. 25, 1985
Applicant:
Inventors:
Assignee:
Blaupunkt Werke GmbH, Hildesheim, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04H / ;
U.S. Cl.
CPC ...
381 16 ; 381 15 ;
Abstract
To permit transmission of traffic information by amplitude modulation in the medium wave band without disturbing audio signals being broadcast, a stereo pilot tone of frequency f.sub.pt below audible range is generated, as well as first and second sinusoidal signals of f.sub.1 =m.sub.1 /n.multidot.f.sub.pt and f.sub.2 =m.sub.2 /n.multidot.f.sub.pt, in which m.sub.1, m.sub.2, and n are different integers. The carrier is modulated by the stereo pilot tone and the first and second sinusoidal signals in such a manner that the phases thereof are different and further, when added, they do not essentially exceed the amplitude of the stereo pilot tone.