Loading...
Turbo product codes for optical recording systems
Author(s)
Date Issued
December 1, 2005
Type
Book Chapter
Abstract
Since the introduction of read-only compact disc (CD-ROM) in the early 80s, optical recording has found its place in mainstream data storage. They are quite a success as removable media particularly in the entertainment and data storage industry. As explosive amount of information in the 90s fueled an ever increasing demand for data storage, further development of optical recording systems in terms of higher capacity, transfer rate and areal density have become major goals in research and development and commercial communities. An evolution of "Blu-ray" and its rival " High-density DVD (HD-DVD)" have recently been envisioned as the next generation optical disc to achieve the recording of a two-hour program in digital HiVision. The standards agree on the capacity of 25 GB with improvement of numerical aperture (NA) and the wavelength alone. As of September 2004, HD-DVD aims to provide 15-GB single-layer disc, and 30-GB dual-layer disc, while Blu-ray aims for upto 27-GB and 54 GB for single-layer and dual-layer discs, respectively [1]. Current formats such as Read-only/Rewritable compact discs (CD-R/RW) and read-only/rewritable digital video discs (DVD-R/RW) are based on storing binary symbols on the optical media. The technology path from CD to DVD employs combined signal processing and coding techniques such as Reed- Solomon codes or RS codes and Runlength-limited codes or RLL codes. To achieve the goal of even higher storage capacity, more sophisticated signal processing and coding techniques would be required. In the early 1990s, there was an evolution of the field of error-correction codes with the introduction of "turbo codes" [2]. For additive white Gaussian noise (AWGN) channel, the novel code provides coding gain that almost reaches the theoretical Shannon capacity. This planted the seed for active research and development in the area of iterative decoding, variants of turbo codes, and turbo equalization in many communication systems. The advanced signal processing and coding such as turbo codes and turbo-like codes thus have a potential of providing additional coding gain as required in the future generations of high-density optical storage systems. In this chapter, the focus is on the use of a variant of turbo codes so called "Turbo Product Codes" [3] in multileveled (ML) optical recording systems. © 2005 Springer. Printed in the Netherlands.
Citation
Turbo Code Applications A Journey from A Paper to Realization, 45-63, 2005