Digital AM demodulator, particularly for demodulating TV signals

A digital AM demodulator comprising:

• a first generator for generating a phase-correlated first carrier signal based upon a correlated signal;
• a first multiplier for multiplying the phase-correlated first carrier signal and an input signal;
• a local generator for generating a local carrier signal not correlated with the input signal but is correlated with a first carrier signal;
• a phase shift detection circuit for detecting a phase shift between the input signal and a local carrier signal;
• a correlator for correlating the first carrier signal with the input signal based upon the detected phase shift for providing the correlated signal to said first generator;
• and
• the detected phase shift and the generated phase-correlated first carrier signal being implemented without using a phase locked loop (PLL).

A television receiver comprising:

• a tuner outputting an input signal to be demodulated;
• an analog/digital converter connected to an output of said tuner;
• and
• a digital AM demodulator connected to an output of said analog/digital converter, said demodulator comprising
• a first generator for generating a phase-correlated first carrier signal based upon a correlated signal,
• a first multiplier for multiplying the phase-correlated first carrier signal and the input signal,
• first and second filters respectively arranged upstream and downstream of said first multiplier for filtering undesired signals,
• a phase shift detection circuit for detecting a phase shift between the input signal and a local carrier signal not correlated with the input signal but is correlated with a first carrier signal, and
• a correlator for correlating the first carrier signal with the input signal based upon the detected phase shift for providing the correlated signal to said first generator.

A method for demodulating a digital AM input signal comprising:

• generating a phase-correlated first carrier signal based upon a correlated signal;
• multiplying the input signal and the phase-correlated first carrier signal to produce a first multiplied signal;
• filtering the first multiplied signal;
• generating a local carrier signal not correlated with the input signal but is correlated with the a first carrier signal;
• determining a phase shift between a frequency of the input signal and a frequency of the local carrier signal;
• and
• correlating a frequency of the first carrier signal with the frequency of the input signal based upon the phase shift for providing the correlated signal.