New Differential Phase Detection Method for Signal Waveform Modulation Multi-Level C

摘要

Signal waveform modulation multi-level (SWML) read-only discs employ sub-lands/sub-pits to achieve multi levels. However, the tracking error signal derived from the conventional differential phase detection (DPD) method deteriorates in the SWML read-only disc owing to sub-lands/sub-pits inserted in the conventional pits/lands. To solve this problem, a new DPD method, which employs a signal adjuster and a phase regenerator, is proposed. The experimental results show that the tracking error signal derived from the new DPD method has better characteristics of uniformity and signal-to-noise ratio than that derived from the conventional DPD method in the SWML read-only disc.