Patent ID: 8139687

Claim:
A digital demodulator adapted in a receiver, wherein the digital demodulator receives an input signal, the digital demodulator comprises: a phase splitter to generate a complex signal according to the input signal; a complex multiplier to multiply the complex signal by both first and second phase signals to generate first and second base band signals, respectively; an automatic frequency controller to receive the first base band signal to generate a first output signal; a limiter to generate a trend signal according to the first output signal; a re-tracker to generate a tuning signal according to the first output signal; a phase detector to multiply the trend signal and the second base signal and to adjust the multiplied signal based on the tuning signal; an oscillator to generate the first and the second phase signals according to the output of the phase detector; and a post-multiplier to multiply the trend signal by the first and second base band signals for output.