Optical disc reproducing apparatus using an asymmetric compensation scheme

An optical disc reproducing apparatus comprising:

• an analog-to-digital (A/D) converter which converts an analog signal obtained from an optical disc to a digital signal;
• an asymmetry compensator which detects and corrects an offset of the digital signal;
• a phase locked loop (PLL) which estimates a clock of the digital signal and compensates for a frequency error;
• a binary module which converts the digital signal to binary data;
• an equalizer which equalizes a particular frequency of the digital signal;
• and
• a channel identifier which detects a reference level of the binary module, based on an input signal of the equalizer,
• wherein the asymmetry compensator comprises:
• a zero crossing detector detecting a zero crossing point by comparing each sign of two consecutive sample signals with respect to the digital signal;
• a decimal asymmetry detector computing a jitter value necessary for an asymmetric waveform level compensation of the digital signal;
• and
• a count determinator determining a coefficient quantity by using a sign bit of a sample signal according to the zero crossing point, the jitter value, and a predetermined system clock cycle.