1. Adaptation and Timing Recovery for Two-Dimensional Optical Storage
- Author
-
Immink, A.H.J., Riani, J., Beneden, van, S.J.L, Bergmans, J.W.M., Ciacci, M., Nowbakht, A., Coene, W.M.J., Lee, van der, A.M., Bruls, D.M., Vijaya Kumar, B.V.K., Kobori, H., Signal Processing Systems, and Signal processing for communications
- Subjects
Signal processing ,Computer science ,business.industry ,Distortion ,Computer data storage ,Detector ,Electronic engineering ,Optical storage ,Spiral (railway) ,business ,Optical disc ,Clock recovery - Abstract
This paper discusses several issues related to adaptation and timing recovery for two-dimensional (2D) optical storage. In the TwoDOS format bits are stored on a 2D hexagonal lattice which is formed by recording multiple bit rows with a fixed phase relation in a so-called broad spiral or meta-spiral. Besides a large increase in data rate by reading out with multiple spots, also a density increase by a factor of two compared to Blu-ray Disc is targeted. To increase the storage density, 2D signal processing is proposed including 2D PRML detection in the form of a stripe-wise Viterbi detector. This detector introduces an increasing detection delay when going from the outer rows towards the center of the broad spiral. For fast control loops in a decision-directed mode, special measures are needed to avoid instability due to this delay. Another issue is the large span of the 2D inter-symbol interference at higher densities and tilt, leading to a large 2D equalizer. Furthermore, in case the broad spiral is recorded with a multiple-pass mastering technology (e.g. for ROM TwoDOS discs), write-channel imperfections such as time-varying lattice distortion require independent timing recovery on each row within the broad spiral.
- Published
- 2004
- Full Text
- View/download PDF