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. 08, 1985
Filed:
Jan. 18, 1982
Johan M Schmidt, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
An FM broadcasting system comprises an FM transmitter for transmitting a multiplex signal which is frequency-modulated on a main carrier wave and an FM receiver for cooperation with said FM transmitter. The multiplex signal comprises: an audio-frequency first information signal and, in the case of a stereo transmission, a second information signal modulated on a suppressed stereo subcarrier, a stereo pilot signal whose frequency (f.sub.p) is situated between the frequency spectra of the two information signals, a first binary-code signal (f.sub.p -f.sub.c) which is phase-modulated on a first code subcarrier situated outside the frequency spectra, which code subcarrier is a harmonic of a subharmonic of the stereo pilot (f.sub.p) which harmonic does not coincide with a harmonic of said pilot (f.sub.p), the multiplex signal, in order to extend the transmission capacity, comprising a second binary-code signal which is phase-modulated on a second code subcarrier (f.sub.p +f.sub.c). The carrier wave information of the two code subcarrier waves can be identified in a simple way by selecting their frequencies to be symmetrical about the stereo pilot signal or its harmonic (3f.sub.p) and by selecting the phase angle between the sum of the two code subcarriers and the stereo pilot or the relevant harmonic thereof to be situated at preferably an integral multiple of .pi./4.