Facsimile and static presentation processing – Static presentation processing – Attribute control
Patent
1984-09-12
1987-01-20
Shepperd, John W.
Facsimile and static presentation processing
Static presentation processing
Attribute control
358 13, 375 77, H04N 965
Patent
active
046383492
ABSTRACT:
The invention relates to a method of and a circuit for digitally demodulating a suppressed-carrier amplitude-modulated signal, of two carriers having the same frequencies Fs in a phase-quadrature relationship, and having a sinusoidal reference signal which is in synchronism with said modulated signal. The method consists in determining the initial angular phase shift .alpha..sub.r, between the reference signal and the sampling signal of the frequency Fe by determining the peak amplitude, as well as the sign of the reference signal and the sign of its derivative for a given sampling instant t.sub.n+m. The successive values .alpha..sub.r +k.phi. of the angular phase shifts relative to said modulated signal are thereafter determined by successively adding the phase shift ##EQU1## The amplitudes of the modulated signal of the two quadrature sub-carriers are determined with the aid of tables containing the values of cos (.alpha..sub.r +k.phi.) and sin (.alpha..sub.r +k.phi.).
REFERENCES:
patent: 4412181 (1983-10-01), Marguinaud et al.
patent: 4503453 (1985-03-01), Rougeolle et al.
Briody Thomas A.
Oisher Jack
Shepperd John W.
Streeter William J.
U.S. Philips Corporation
LandOfFree
Method of and circuit for digitally demodulating an amplitude-mo does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of and circuit for digitally demodulating an amplitude-mo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of and circuit for digitally demodulating an amplitude-mo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2137932