PLL APPARATUS FOR OFDM SYSTEM HAVING VARIABLE CHANNEL BANDS AND OPERATING METHOD THEREOF

摘要

Provided are a PLL apparatus for an OFDM system having variable channel band and an operating method thereof. The PLL apparatus includes a frequency divider for dividing an oscillating signal; a phase detector for detecting a phase difference between a reference signal and the divided oscillating signal from the frequency divider and outputting the phase difference signal; a variable loop filter for filtering a phase difference signal outputted from the phase detector; a voltage control oscillator for outputting the oscillator signal to the frequency divider according to the voltage control signal filtered from the variable loop filter; and a variable loop filter controller for varying a filtering band of the variable loop filter according to each of the channel bands.