| 摘要 |
PURPOSE: A device for compensating carrier frequency offset by using various frequency offset estimation ranges is provided to use both of a frequency offset estimation value when a carrier frequency offset estimation range is wide and a frequency offset estimation value when the range is narrow stepwise, thereby improving the frequency offset estimation ranges mutually related in trade-off and estimation performance. CONSTITUTION: An LPF(Low Pass Filter)(701) passes only low frequency bands of received signals. An A/D(Analog-to-Digital) converter(702) converts analog signals outputted in the LPF(701) into digital signals. A frequency offset estimator(703) has various frequency offset estimation ranges by being composed of detection pairs having mutually different symbol delay times from a reference detection pair, to calculate various frequency offset estimation values. A selector(704) receives a frequency offset value of the frequency offset estimator(703) having the most wide frequency offset estimation range, and sequentially receives frequency offset values having narrower frequency offset estimation ranges at predetermined time intervals. A loop filter(705) performs a filtering operation corresponding to a frequency offset value selected in the selector(704). And a VCO(Voltage Controlled Oscillator)(706) receives an output signal of the loop filter(705) and generates an oscillating signal corresponding to a voltage of the signal, then feeds back the generated signal to an input terminal of the LPF(701), to compensate frequency offset.
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