Analysis of differential phase detection signal of a novel multi-level read-only disc

To improve the tracking scrvo performance,a novel signal waveform multi-level(SWML)read-only disc realized on the digital versatile disc(DVD)platform is presented.The characteristic of the differential phase detection(DPD)signal of the SWML read-only disc is analyzed both in theory and experiment.The atnplitude of the DPD signal of the SWML read-only disc in an open tracking servo loop is about 2/3 of that of the DVD read-only disc.The uniformity and symmetry of the DPD signal of the SWML read-only disc are similar to those of the DVD read-only disc and better than the former multi-level run-length limited(ML-RLL)read-only disc.