Signal processing for 15/27 GB read-only disk system

In order to realize 15/27 GB read-only disk systems using blue laser, new s ignal processing is required. The technology of large-scale integrated circ uits has advanced considerably. Hence we can use a complicated circuit with a big gate size without increasing the system cost significantly when we f abricate the blue laser disk system. We have realized the 15/27 GB system u sing the two-dimensional equalizer and the limit equalizer. The two-dimensi onal equalizer was composed of the cross-talk cancel system and the asymmet ry compensation type tangential adaptive equalizer. And could improve the d eterioration due to the inter symbol interference and the cross-talk from t he adjacent tracks. The limit equalizer could improve the deterioration due to the disk noise. Using these signal-processing systems, we could reduce the bottom jitter by more than 3% and expand the tilt margin.