| Project/Area Number |
03650267
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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 | Tohoku University |
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Principal Investigator |
KAWAMATA Masayuki Tohoku University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (70153004)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Frequency scramble / Multidimensional digital filter / Periodically shift-variant digital system / Secure communication |
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| Research Abstract |
This research studies multidimensional frequency scramble for secure communication of speech and images using multidimensional linear periodically shift-variant digital filters (LPSV filters). The notion of a generalized multidimensional transfer function is presented for LPSV filters. The frequency characteristic of the filters is discussed in terms of this transfer function. LPSV filters can serve as a frequency scrambler, because they can decompose the spectrum of an input signal into some spectral partitions and rearrange the spectrum. 2-D LPSV filters are designed based on the 1-D Parks-McClellan algorithm. The resultant LPSV filters divide the input spectrum into some components that are permuted and possibly inverted with keeping the symmetric of the spectrum. Application of the proposed scrabble method shows the effectiveness of frequency scramble for real images.
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