Soft-Encoding Scheme of 3/4 Tone-Controllable Code for Channel Iteration of Low-Density Parity-Check Code on the Holographic Data Storage

Soft-Encoding Scheme of 3/4 Tone-Controllable Code for Channel Iteration of Low-Density Parity-Check Code on the Holographic Data Storage

In turbo equalization for holographic data storage (HDS) systems, an iterate-back signal must pass through a modulation coding process for channel iteration since the iterate-back signal is a demodulated signal and the input of a detector is modulated data. Also, the iterate-back signal is a soft-va...

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Bibliographic Details
Published in:Japanese Journal of Applied Physics Vol. 51; no. 8; pp. 08JD03 - 08JD03-4
Main Authors: Park, Donghyuk, Lee, Jaejin
Format: Journal Article
Language:English
Published: The Japan Society of Applied Physics 01-08-2012
Online Access:Get full text
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Summary:In turbo equalization for holographic data storage (HDS) systems, an iterate-back signal must pass through a modulation coding process for channel iteration since the iterate-back signal is a demodulated signal and the input of a detector is modulated data. Also, the iterate-back signal is a soft-value, so the soft-input and soft-output (SISO) must be treated by a modulation code. A 3/4 tone-controllable (TC) code can control the ratio of ON and OFF pixels on each data page. The memory capacity of a holographic data storage system can be increased if we use a TC code. In this paper, we concatenate a 3/4 TC code and LDPC code, and then simulate the turbo equalization performance on a HDS channel. A SISO 3/4 TC code is needed for this simulation. Therefore, we propose a soft-encoding scheme for a SISO 3/4 TC code.
Bibliography:The block diagram for channel iterative decoding for an HDS system. An encoding table for a 3/4 TC code. A soft encoding table for a 3/4 TC code when $| \mathrm{LLR}(d_{1}) | > | \mathrm{LLR}(d_{2}) | > | \mathrm{LLR}(d_{3}) |$. Flow chart for the soft-encoding table when the number of input bits is $n$. BER performance of the channel iteration with a soft-modulation code.
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.51.08JD03