METHOD FOR SYNCHRONIZING MODULATION ENCODED DATA WITH DATA CLOCK, PHASE ERROR ESTIMATION DEVICE AND DIGITAL PHASE ERROR ESTIMATION DEVICE

摘要

PURPOSE: To synchronize data read from a recording medium with data clocks by accurately performing comparison with a modulation code measured value at the time, predicting a phase error, normalizing a detection error and deciding the slope of a modulation code before and after respective detection peaks. ;CONSTITUTION: Continuous samples and data bits are supplied to a phase error prediction device 20 connected to a detector 18 and a phase difference between the data clocks and the modulation codes is decided. The detector 18 is positioned inside a loop between a read equalizer 16 and the prediction device 20 and the detector 18 is designed so as to generate slight propagation delay. The samples at the time N-1 and N+1 are respectively compared with expected values in the prediction device 20 constituted in such a manner, the difference is decided and the difference is corrected corresponding to the polarity of the detection peak. Thereafter, the difference is multiplied with an appropriate slope factor, the difference corrected by the slope is added further and phase error prediction is obtained.;COPYRIGHT: (C)1993,JPO