ITE Technical Report
Online ISSN : 2424-1970
Print ISSN : 1342-6893
ISSN-L : 1342-6893
25.82
Displaying 1-8 of 8 articles from this issue
  • Article type: Cover
    Pages Cover1-
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Article type: Index
    Pages Toc1-
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Hisahi OSAWA, Nobuhiko SHINOHARA, Yoshihiro OKAMOTO, Hidetoshi SAITO, ...
    Article type: Article
    Session ID: MMS2001-115
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    The performance of noise predictive maximum likelihood(NPML)system in a perpendicular magnetic recording channel with jitter-like media noise is studied. The bit error rates of NPML systems for the PR2, E^2PR3 and E^2PR4 channels are obtained by computer simulation and theoretical method. The relationship between the ratio R_J of the jitter-like media noise power to the total noise power at the reading point and the required SNR to achieve a bit error rate of 10^<-4> is also obtained and compared with that of the conventional PRML system. The results show that the SNR improvements of NPML systems over PRML systems are about 2.1, 2.8 and 5.6 dB for the PR2, E^2PR3 and E^2PR4 channels, respectively, at a normalized linear density of 1.5 and R_J=50%.
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  • Kazuhito ICHIHARA, Takao SUGAWARA, Yuichi SATO, Toshihiko MORITA
    Article type: Article
    Session ID: MMS2001-116
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    We study performance of 8/9 LDPC method, one of iterative decoding methods, after ECC in a magnetic read/write channel. The result shows that an ECC-less LDPC method, which eliminates ECC and eases linear bit denslty, is more effective than the LDPC method with ECC and achieves 2.6dB against conventional Viterbi detection. Furthermore, we developed an iterative decoding method with noise prediction that consists of ECC-less LDPC and Noise Predictive MAP. This iterative decoding method achieves 0.3dB and 0.7dB gain, ratios of media noise to white noise are 1/1 and 9/1 respectively, against ECC-less LDPC.
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  • Takahiro KUROSAWA, Naoki HONDA, Kazuhiro OUCHI
    Article type: Article
    Session ID: MMS2001-117
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Inter-track orthogonal coding was applied perpendicular magnetic recording using double layered media and MR head reading. Three-track collective reading was achieved with a track pitch of 0.12 μm at a linear density of 100 kFRPI. Off-track margin of three-track collective reading was 0.05 μm when a read head with a track width of 0.32 μm was used. Using the code sequences of 4×4 Hadamard matrix, the error rate less than 10^<-4> is achievable with the SNR of about 10-13 dB.
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  • Weixing XIA, Hiroaki MURAOKA, Yoshihisa NAKAMURA
    Article type: Article
    Session ID: MMS2001-118
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Relationship between head field gradient of single pole head and magnetization transition parameter are evaluated in perpendicular double layered medium by using a computer simulation. It is clearly shown that when field gradient become larger, the width of magnetization transition becomes smaller monotonously. And for the medium, a steeper magnetization transition can be written when slope of hysteresis loop increases. Based on the cusp field SPT head, the structure optimization by locating the upper return path in the vicinity of the main pole was investigated to increase the field gradient. Resultant recorded transition widths were examined as well.
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  • Yasushi KANAI, Ryo MATSUBARA, Koji Fujiwara, Norio TAKAHASHI
    Article type: Article
    Session ID: MMS2001-119
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    High-density longitudinal magnetic recording write heads are investigated by using transient finite element analysis. First, conventional write heads are analyzed and the issue is discussed. Then, a planar type write head is mentioned and the possibility(large recording field strength)and the issue(large cross-track field)are noted. Finally, the head structure optimization using the FEM are carried out and the planar head having large recording field and less cross-track field is obtained.
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  • Article type: Appendix
    Pages App1-
    Published: December 14, 2001
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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