| Project/Area Number |
08680354
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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 |
計算機科学
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| Research Institution | University of Electro-Communications |
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Principal Investigator |
MORITA Hiroyoshi The graduate School of Information Systems, Assoc.Professor, 大学院・情報システム学研究科, 助教授 (80166420)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | frame syn-chronization / insertion / deletion errors / Varshamov-Tanengoltx'code / prefix synchronizatio code / distributed marker / partial prafix / error correcting codes / シンボル削除 / シンボル挿入 / prefix / frame synchronization |
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| Research Abstract |
1. Derivation of Encoding and Decoding Algorithms on Prefix Synchronized Codes with Distributed Markers
Prefix synchronized code is a set of codewords of a fixed length, each of which is given by concatinating a common marker and a constrained sequence conveying input information. A constrained sequence satisfies the condition such that the marker appears only at the beginning of the corresponding codeword. Therefore, by finding the marker's position we can easily recover the synchronization of a sequence of codewords even if a slip page error might occur.
In this research we introduced a new class of prefix synchronized codes having distributed marker in which symbols are not necessarily consecutive to each other. The proposed Partial Prefix Synchronized (PPS) codes can increase coding rate comparing with traditional prefix synchronized codes of the same codeword length. We derived encoding and decoding algorithms of PPS codes based on enumerative coding.
2. Construction of Distributed Marker
We obtained the maximum length of distributed markers given a number of bits having fixed valued in the marker and give a method to construct the maximum dsitributed markers.
3. Symbol Insertion/Deletion Error Correcting Prefix Synchronized Codes
Prefix Synchronized codes capable of correcting two symbol insertion/deletion errors are derived, The proposed codes can recover frame syncrhonization and correct symbol ins/del errors if slip page error and symbol errors do not occur simultaneously.
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