| Project/Area Number |
62550247
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子通信系統工学
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| Research Institution | Ehime University |
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Principal Investigator |
TAZAKI Saburo Faculty of Engineering, Ehime Univ. Professor, 工学部, 教授 (00036394)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Yoshio Faculty of Engineering, Ehime Univ. Assistant, 工学部, 助手 (00110833)
OSAWA Hisashi Faculty of Engineering, Ehime Univ. Professor, 工学部, 教授 (50029336)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1987: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Recording code / FM family code / Finite Automaton model / Viterbi decoding method / Partial response system / Jacoby type ternary code / Digital VTR / 光磁気記録システム / スライデングブロック方式 / 光磁気記録 / パーシャルレスポンス方式 / ビタビ復号 |
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| Research Abstract |
The basic concepts for the imformation density improvements in recording codes are summarized as follows:
(1) to include DC-free property in order to restrict cross-talk and dc wandering, (2) to set T_<min> as large as possible in order to reduce the influence of intersymbol interference, where T_<min> is the time separation between two successive polarity changes in recording waveform, (3) to incease channel capacity as a function of several constaint parameters with respect to system design.
Although a lot of recording codes are already proposed in this respect, there have been few publications with classification of the code. We introduced the finite automaton model as a useful tool for theoretical description of the coding rule and for facilitation of performance comparison among various proposed codes.FM code, one of the most famous and powerful codes, and its family codes have been investigateds to obtain fundamental insights for systematization of recording codes. It turns out that some conventional codes are identified with FM family codes.
The reproduction process of signals in digital recording systems is not required to be a reciprocal function of recording process. For this reason, we adopted Partial Response(PR) systems for equalizing the detected signal and Viterbi algorithm in stead of bit-by-bit decoding method. We also assumed additive noise to be colored. As the results, significant improvements on both effective signal-to-noise ratio and bit error rate are performed.
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