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Increasing the Information Density of Storage Systems Using the Precision-Resolution Paradigm

Schwartz, Moshe and Bruck, Jehoshua (2007) Increasing the Information Density of Storage Systems Using the Precision-Resolution Paradigm. California Institute of Technology , Pasadena, CA. (Unpublished)

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Arguably, the most prominent constrained system in storage applications is the (d, k)-RLL (Run-Length Limited) system, where every binary sequence obeys the constraint that every two adjacent 1's are separated by at least d consecutive 0's and at most k consecutive 0's, namely, runs of 0's are length limited. The motivation for the RLL constraint arises mainly from the physical limitations of the read and write technologies in magnetic and optical storage systems. We revisit the rationale for the RLL system and reevaluate its relationship to the physical media. As a result, we introduce a new paradigm that better matches the physical constraints. We call the new paradigm the Precision-Resolution (PR) system, where the write operation is limited by precision and the read operation is limited by resolution. We compute the capacity of a general PR system and demonstrate that it provides a significant increase in the information density compared to the traditional RLL system (for identical physical limitations). For example, the capacity of the (2, 10)-RLL used in CD-ROMs and DVDs is approximately 0.5418, while our PR system provides the capacity of about 0.7725, resulting in a potential increase of about 40% in information density.

Item Type:Report or Paper (Technical Report)
Schwartz, Moshe0000-0002-1449-0026
Bruck, Jehoshua0000-0001-8474-0812
Additional Information:This work was supported in part by the Caltech Lee Center for Advanced Networking and by NSF grant ANI-0322475. Available online:
Group:Parallel and Distributed Systems Group
Subject Keywords:run-length limited, constrained coding, capacity of constrained channels
Record Number:CaltechPARADISE:2007.ETR078
Persistent URL:
Usage Policy:You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.
ID Code:26109
Deposited By: Imported from CaltechPARADISE
Deposited On:27 Feb 2007
Last Modified:09 Mar 2020 13:19

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