Translator Disclaimer
8 December 1995 Coding for higher-order partial-response channels
Author Affiliations +
Proceedings Volume 2605, Coding and Signal Processing for Information Storage; (1995) https://doi.org/10.1117/12.228239
Event: Photonics East '95, 1995, Philadelphia, PA, United States
Abstract
Partial-response maximum-likelihood (PRML) methods are now being adopted in many digital magnetic recording systems. It is expected that as linear densities continue to increase, there will be a need to use 'extended' PRML techniques. In fact, commercial systems incorporating extended partial-response target channels, denoted EPRML and EEPRML, employing the EPR4 transfer polynomial h(D) equals 1 plus D minus D2 minus D3 and the EEPR4 transfer polynomial h(D) equals 1 plus 2D minus 2D3 minus D4, respectively, have recently appeared. Among these systems, several apply the rate 2/3, (d,k) equals (1,7) runlength-limited code, originally designed for use with peak-detection, in combination with a detector trellis structure reflecting the d equals 1 constraint. In the EEPR4 case, the d equals 1 constraint is known to provide a coding gain of 2.2 dB, unnormalized for the rate loss, relative to the uncoded channel. In this paper, we describe a nested family of code constraints, properly containing the d equals 1 constraint, intended for use on the EEPR4 channel. These constraints are shown to have the same distance-enhancing properties as the d equals 1 constraint. They permit the design of practical codes for EEPR4 that offer the same coding gain as the (1,7)-coded system, but with higher achievable code rates. The paper concludes with the construction for such a code which, having rate 4/5, offers a 20% increase over the 1,7) code.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Razmik Karabed and Paul H. Siegel "Coding for higher-order partial-response channels", Proc. SPIE 2605, Coding and Signal Processing for Information Storage, (8 December 1995); doi: 10.1117/12.228239; https://doi.org/10.1117/12.228239
PROCEEDINGS
12 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

Measurement of whole tire profile
Proceedings of SPIE (December 27 2010)
Fast computation of the grassfire transform using SKIPSM
Proceedings of SPIE (October 02 1994)
On track and off track distance properties of Class 4...
Proceedings of SPIE (December 07 1995)

Back to Top