| Project/Area Number |
10650352
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
情報通信工学
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
FUJIWARA Eiji Graduate School of Information Science and Engineering, TOKYO INSTITUTE OF TECHNOLOGY, Professor, 大学院・情報理工学研究科, 教授 (20211526)
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| Co-Investigator(Kenkyū-buntansha) |
KITAKAMI Nasato Chiba University, Faculty of Engineering, Lecturer, 工学部, 講師 (20282832)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | unequal error control (UEC) codes / unequal error protection (UEO codes / fixed byte / byte errors / burst errors / 不均一誤り制御符号 / 誤り制御符号 / UEC符号 |
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| Research Abstract |
This research project proposes a class of unequal error control codes, or UEC codes, for the words which consist of multiple blocks with unequal importance levels. As simple and practical codes, the following two-level UEC codes are proposed.
(1) Four types of UEC codes which corrects any errors in the first block, called as fixed byte, are proposed. All of the proposed codes are optimal and their parallel decoders require less than 50% hardware augmentation compared to that of the conventional SEC-DED codes. From the above, the proposed codes can be regarded as practical.
(2) Five types of codes which protect the first block against single-byte errors are proposed, where the first block consists of multiple bytes. These codes protect the first block more strongly than ordinary UEC codes and are called as unequal error protection codes, or UEP codes. The proposed codes are close to the bounds. Computer simulations say that the errors beyond error control capability of the codes hardly miscorrect the first block.
(3) Single-bit error correcting UEP codes which protect the first block against burst errors are proposed. The check matrices of the proposed codes are product of two types of matrices, those of the conventional burst error correcting codes and the proposed ones. The serial decoding method is also proposed. The obtained codes are close to the bounds if there exist good burst error correcting codes which are close to the bounds.
In this project, the investigators have found that the proposed UEP codes are suitable for error tolerance in lossless data compression. Since the error in the former part of the compressed data gives more serious damage to the decompression than that in the latter one, the former part should be strongly protected against errors than the latter one by the UEP codes.
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