2002 Fiscal Year Final Research Report Summary
Digital Signal Processing with Optimal Analog Performance via Sampled-data Control Theory
| Project/Area Number |
12450172
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Control engineering
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
YAMAMOTO Yutaka Kyoto University, graduate school of Informatics, Professor, 情報学研究科, 教授 (70115963)
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| Co-Investigator(Kenkyū-buntansha) |
WAKASA Yuji Yamaguchi University, Faculty of Engineering. Lecturer, 工学部, 講師 (60263620)
FUJIOKA Hisaya Kyoto University, graduate school of Informatics, Assoc. Professor, 情報学研究科, 助教授 (60273596)
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| Project Period (FY) |
2000 – 2002
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| Keywords | sampled-data control / digital signal processing / H-infinity optimal performance / communication systems / convex optimization / sound / image processing |
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| Research Abstract |
This research project intends to develop a new theory and method of signal processing that optimize analog performance via modern sampled-data control theory. This is made possible only via sampled-data control theory in that this theory can take intersampling behavior into account. This is in marked contrast to the Shannon sampling theorem which is so popular in signal processing community. In such a conventional approach, one usually resorts to the assumption that the original analog signals must be fully band-limited. This artificial assumption is never fulfilled in reality. Furthermore, it has an added artifact that it produces an unnecessary overshoot in many signals. The present research has successfully derived a filter that gives rise to a suboptimal analog performance, and it has been guaranteed that it gives a superior result in sound processing. This has been also assured in a lab experiment in which we implemented an optimal digital filter to a PC with DSP board. The constructed DA converter realized in such a DSP circuit easily outperformed the current high-end CD players available at the moment.
We have also obtained a new design method for optimal sample-rate converters, and also a design method for optimal filters for digital communication systems. A new numerical design method has also been developed since the design problem in these applications tend to be high-dimensional. It has been shown that a convex optimization problem, the so-called cutting-plane method, is very effective in such problems.
Finally, it has been observed that application to image processing of such filters can be a prospective direction for future research.
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