Patent ID: 6751270
Filing Date: 2004-06-15
Classification: H03J,H04L

Abstract:
A carrier frequency recovery apparatus for simultaneously reducing a frequency offset and a phase error, comprising:a phase detection means for estimating a phase error of an I-channel and Q-channel signals having a frequency offset; a select signal generating means for receiving the phase error and generating a select signal; a first loop filter means for attenuating the phase error by a predetermined range; a second loop filter means for attenuating the phase error in a range narrower than the first loop filter means; an addition means for adding an output value of the first loop filter means to an output value of the second loop filter means; a multiplexing means for selectively outputting the output value of the first loop filter means or an output value of the addition means in response to the select signal; and a voltage-controlled oscillation means for storing and outputting cosine and sine signals corresponding to an output value of the multiplexing means, wherein the cosine and sine signals are used to correct the frequency offset of the I-channel and Q-channel signals.