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Two-Dimensional Constant-Weight Block code in Orthogonal Aperture-Multiplexing for Multilayered Waveguide Holographic Memory

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JAPANESE JOURNAL OF APPLIED PHYSICS 2008年第11期47卷 8440-8445页

作者： Ueno, Masahiro Endo, Masahiro Kurokawa, Yoshiaki Yoshikawa, Hiroshi Ando, Yasuko Yagi, Shogo Imai, Tadayuki Furuya, Akinori Ohtani, Yoshimitsu NTT Corp NTT Cyber Space Labs Tokyo 1808585 Japan NTT Corp NTT Photon Labs Kanagawa 2430198 Japan NTT Corp NTT Microsyst Integrat Labs Kanagawa 2430198 Japan

For a two-dimensional constant-weight block code, we show that the recording density is proportional to code rate and the second power of the size of the bright point. Second, we show four constant-weight block codes (two 2:16 codes, a 4:24 code, and a 4:16 code) with different code rates. In simulation experiments, we measured the maximum size of bright points for each code, the bit error rate was practical (10(-4) or less), and simulation results show that the maximum size increases as the code rate decreases. Then, we show that the highest recording density is achieved with the two 2:16 codes and the 4:24 code and that these codes are suitable for orthogonal aperture-multiplexing. We also show that there is a trade-off between multiplexity and the code rate. [DOI: 10.1143/JJAP.47.8440]

关键词： constant-weight block code modulation code orthogonal aperture multiplexing multilayered waveguide holographic memory bit error rate recording density

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Theoretical method of calculating raw bit-error-rate of 2:N constant-weight block code for multilayered waveguide holographic memory

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JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 2007年第11期46卷 7347-7355页

We present an expression for the probability density functions of the ON and OFF pixels of a 2:N constant-weight block code to estimate the raw bit error rate (BER). We also show that they are similar to Gaussian ones through an analysis of an actual code image reconstructed from a multilayered waveguide holographic memory. From these results, we show that this expression for estimating the raw BER can be obtained using averages and standard deviations of the ON and OFF pixels. Finally, we demonstrate that the relationship between the signal-to-noise ratio and the raw BER derived from the expression for estimating the raw BER closely fits simulation results. This expression is useful for roughly estimating the value of the raw BER from the averages and standard deviations of the ON and OFF pixels.

关键词： constant-weight block code modulation code probability density function multilayered waveguide holographic memory signal-to-noise ratio bit error rate

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New efficient run-length limited code for multilevel read-only Optical Disc

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JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 2007年第6B期46卷 3782-3786页

作者： Hu, Hua Pan, Longfa Xiong, Jianping Ni, Yi Tsinghua Univ Opt Mem Natl Engn Res Ctr Dept Precus Instrument & Mechanol Beijing 100084 Peoples R China

Multilevel recording with run-length limited (RLL) modulation is a novel way to significantly increase the recording density without changing the optical or mechanical units of current optical, disc systems. In this paper, a new efficient 4-ary RLL(2, 13) code with special constraint is designed for four-level RLL modulation on read-only digital versatile disc (DVD-ROM). This code can result in alternate multilevel pits and lands on the disc, and reduce the difficulty of multilevel disc replication. Further more, simulation results show the symbol error rate (SER) performance can be improved about 3 dB when the proposed code is used for optical recording channel with partial-response maximum-likelihood (PRML) detection.

关键词： modulation code multilevel recording run-length limited codes M-ary RLL codes

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A new two-dimensional pseudo-random modulation code for holographic data storage

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JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 2003年第2B期42卷 1010-1013页

作者： Hwang, E Roh, J Kim, J Cho, J Park, J Jung, H DAEWOOD Elect Co Ltd Digital Media Lab KyongGi Do 435733 South Korea

A new two-dimensional modulation scheme for holographic data storage, or complementary code-word block modulation (CCBM), and its decoding algorithm have been developed and evaluated. The CCBM constructs a pseudo-random array which provides a relatively uniform intensity distribution in the recording plane, leading to favorable SNR and BER performance.

关键词： holographic data storage holographic memory channel code modulation code pseudo-random array

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A PRML with modified branches of a dual MTR code for high-density PMR channels

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JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 2005年第287期287卷 410-415页

作者： Lee, J Lee, J Dongguk Univ Dept Elect Engn Chung Ku Seoul 100715 South Korea

Maximum transition run (MTR, j) code is a modulation code that limits the consecutive transitions. We present a dual MTR code that can be applicable to high-density perpendicular magnetic recording (PMR) channels. The code restricts j=2 in each codeword and allows j=3 when codewords are connected. Furthermore, to improve the detection performance of the PMR systems, we propose a partial response maximum likelihood (PRML) detection scheme with modified branches of the Viterbi trellis for the code. The PRML detection of the dual MTR code achieves an SNR gain of more than 2 and 0.3 dB over the conventional fourth-order PRML detections with rate 8/9 code and rate 6/7 MTR (j=2) code at 10(-5) bit error rate (BER) in the PM R channel model, respectively. (C) 2004 Elsevier B.V. All rights reserved.

关键词： modulation code MTR coding PRML Viterbi detector with modified branch metric

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Signal processing method of holographic memory using image distortion correction and soft decision Viterbi decoding method

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JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 2005年第5B期44卷 3508-3512页

作者： Sato, D Nishimoto, K Katayanagi, Y Yamamoto, M Tokyo Univ Sci Grad Sch Ind Sci & Technol Noda Chiba 2788510 Japan

The signal quality of holographic memory is greatly lowered by the pixel mismatch between the charge-coupled device (CCD) and the reproduced image caused by image distortion. This paper discusses an approach to improve the signal quality by using two step decoding method. By this method, first, distortion correction is done to improve the degree of pixel mismatch to obtain better signal to noise ratio (SNR). Then, to eliminate errors such as noise that cannot be removed by distortion correction, soft decision Viterbi decoding using the newly defined reliability is used to correct errors. The effectiveness of this two step decoding method was tested by computer simulation, and its effect to improve SNR and reduce errors was confirmed.

关键词： holographic memory distortion correction Viterbi decoding soft decision reliability modulation code

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Signal processing method of holographic memory using image distortion correction and soft decision Viterbi decoding method

Signal processing method of holographic memory using image d...

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14th International Symposium on Optical Memory

作者： Sato, D Nishimoto, K Katayanagi, Y Yamamoto, M Tokyo Univ Sci Grad Sch Ind Sci & Technol Noda Chiba 2788510 Japan

关键词： holographic memory distortion correction Viterbi decoding soft decision reliability modulation code

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A PRML with modified branches of a dual MTR code for high-density PMR channels

A PRML with modified branches of a dual MTR code for high-de...

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7th Perpendicular Magnetic Recording Conference (PMRC 2004)

作者： Lee, J Lee, J Dongguk Univ Dept Elect Engn Chung Ku Seoul 100715 South Korea

关键词： modulation code MTR coding PRML Viterbi detector with modified branch metric

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A new efficient error correctible modulation code for holographic data storage

A new efficient error correctible modulation code for hologr...

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International Symposium on Optical Memory (ISOM2001)

作者： Hwang, E Kim, K Kim, J Park, J Jung, H DAEWOO Elect Co Ltd Digital Media Lab KunPo 435733 KyongGi South Korea

A new efficient modulation code for holographic memory. or 9 : 12 pseudo-balanced code(9-12PBC), has been developed and evaluated. The proposed code is partitioned into 16 codeword subsets and is decoded in conjunction with Viterbi algorithm. The results of numerical simulations and actual recording experiments show that 9-12PBC gives favorable trade-off between code rate and bit error rate(BER) performance.

关键词： holographic data storage holographic memory channel code modulation code Viterbi algorithm correlation decoding

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Two-dimensional modulation code for multilayered waveguide holographic memory

Two-dimensional modulation code for multilayered waveguide h...

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International Symposium on Optical Memory (ISOM2001)

作者： Endo, M Kurokawa, Y Ueno, M Tanabe, T Yamamoto, M NTT Corp NTT Cyber Space Labs Musashino Tokyo 1808585 Japan

Our two-dimensional modulation code improves the decoding accuracy of images reconstructed from a multilayered waveguide holographic memory that have been translated, rotated, and distorted with respect to the image detector, The reconstructed images can be decoded without using a precision mechanical structure or an imaging mechanism that matches pixels of the reconstructed images to the pixel grid of the image detector. This code also improves the bit error rate of distorted reconstructed images and reduces crosstalk among different layers and image detector saturation.

关键词： multilayered waveguide holographic memory modulation code pixel-matching signal-to-noise ratio bit error rate

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