| Project/Area Number |
01460145
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | The University of Tokyo |
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Principal Investigator |
HATORI Mitsutoshi The University of Tokyo, The Faculty of Engineering, Professor, 工学部, 教授 (60010790)
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| Co-Investigator(Kenkyū-buntansha) |
AIZAWA kiyoharu The University of Tokyo, The Faculty of Engineering, Lecturer, 工学部, 講師 (20192453)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1989: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | Radio Communication / Mobile Communication / Adaptive Equalization / Adaptive Power Control / Tap Selection / State Clustering / Reference Signal / Frequency Conversion / FMマルチパス歪 / 零周波数帯 / ダイナミックチャネル配置 / 広帯域都市内無線通信 / 自動等化 / 適応等化器 |
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| Research Abstract |
Due to the variations in weather conditions etc., transmission channel characteristics of radio communication systems change frequently.
In the present research, in order to construct the radio communication system which can absorb the above mentioned changes, the following matters were taken into consideration during the research.
1. An adaptive power control for the transmission mechanism of a wideband intra city communication network.
Investigations were carried out to realize the stability of receiving level of a communication system by an adaptive controlling method in compliance with the response lovel of the receiver. By using this method, the reduction of average transmission power and the reduction of channel interference w
ere realized. 2. High speed adaptive equalization algorithm for a digital mobile communication system.
(1) A new adaptive equalization method, "Adaptive Equalization Based on State Clustering", was proposed, which was based on the knowledge of the transmission p
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ropagation conditions. It was recognized that this method could follow the abrupt changes of the transmission channel characteristics better than RLS method which is one of the fastest algorithms available so far.
(2) A new tap selection algorithm using threshold was proposed. It was recognized that this was a better method than others already available, in terms of ability to follow the changes of the system characteristics.
3. FM multipath distortion cancelling algorithm using a reference signal.
Investigation have been carried out so far to cancel the FM multipath distortion using one of FM waves characteristics, constant amplitude. Moreover an equalization algorithm using a reference signal is examined. In this method, by shifting the intermediate frequency (where we usually work the canceller) of the signal to the zero frequency level using an frequency conversion technique, the processing speed requirement for the hardware was reduced. And, by using the reference signal, a particular enhancement of the performance level was realized. Less
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