Digital intermediate frequency demodulator
First Claim
1. A digital intermediate frequency (IF) demodulator for processing a digital IF signal converted from a radio frequency (RF) signal, comprising:
- an NCO outputting a sine value and a cosine value;
a down conversion circuit outputting a first zero IF signal comprising a first real part signal and a first imaginary part signal, according to the digital IF signal, the sine value and the cosine value;
a PIF carrier recovery circuit outputting a loop error signal for the NCO and a second zero IF signal, according to the first zero IF signal and a video synchronization signal; and
a video baseband demodulator generating a composite video signal according to the second zero IF signal.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention discloses a digital IF demodulator for processing a digital IF signal converted from a radio frequency (RF) signal, including an NCO, a down conversion circuit, a PIF carrier recovery circuit and a video baseband demodulator. The NCO outputs a sine value and a cosine value. The down conversion circuit outputs a first zero IF signal including a first real part signal and a first imaginary part signal, according to the digital IF signal, the sine value and the cosine value. The PIF carrier recovery circuit outputs a loop error signal for the NCO and a second zero IF signal, according to the first zero IF signal and a video synchronization signal. The video baseband demodulator generates a composite video signal according to the second zero IF signal.
-
Citations
11 Claims
-
1. A digital intermediate frequency (IF) demodulator for processing a digital IF signal converted from a radio frequency (RF) signal, comprising:
-
an NCO outputting a sine value and a cosine value; a down conversion circuit outputting a first zero IF signal comprising a first real part signal and a first imaginary part signal, according to the digital IF signal, the sine value and the cosine value; a PIF carrier recovery circuit outputting a loop error signal for the NCO and a second zero IF signal, according to the first zero IF signal and a video synchronization signal; and a video baseband demodulator generating a composite video signal according to the second zero IF signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification