| Project/Area Number |
61850057
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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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 | Kyoto University |
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Principal Investigator |
IKEGAMI Fumio Kyoto University, Professor, 工学部, 教授 (20093180)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAHATA Kunihiko Mitsubishi Electric, Manager of Commun. Equip. Dept., 通信機製作所, 次長
KIKUMA Yoshinobu Kyoto University, Instructor, 工学部, 助手 (40195219)
TAKEUCHI Tsutomu Kyoto University, Instructor, 工学部, 助手 (20154974)
YOSHIDA Susumu Kyoto University, Associate Professor, 工学部, 助教授 (50026324)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥24,600,000 (Direct Cost: ¥24,600,000)
Fiscal Year 1988: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥8,700,000 (Direct Cost: ¥8,700,000)
Fiscal Year 1986: ¥13,900,000 (Direct Cost: ¥13,900,000)
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| Keywords | Mobile Communication / Digital Mobile Radio / Bit-Error-Rate / Multipath Propagation / Fading / Directive Antenna / 遅延プロフィール / 耐多重波変復調方式 / 伝送品質評価 / ディジタル通信 / 耐多重波変調方式 |
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| Research Abstract |
We have proposed a novel anti-multipath modulation technique double phase shift keying (DSK) for digital mobile radio and confirmed its delay-spread-resistant performance by computer simulation and laboratory measurements. The purpose of this project was to make a feasibility study of high speed digital mobile data transmission using DSK in an actual urban area with complicated multipath delay profiles. Main results are as follows:
1. Transmitters and receivers of DSK up to 1 Mbps and also BPSK, for comparison, were implemented. Modulators are of quadrature type with baseband waveforms stored in ROM's. Demodulators are differential detectors with SAW as delay elements. A delay simulator up to 30 sec was also implemented for laboratory experiments.
2. According to the field tests in Kyoto, DSK showed superiof bit-error-rate so long as the multipath delay is less than a half bit interval. Data transmission at 512 kbps within Kyoto Univ Campus and at 128 kbps on the streets near kyoto univ was acceptable, while not for BPSK.
3. A directive antenna was confirmed to be effective to suppress the long-delayed signal, and thus to improve bit-error-rate for both DSK and BPSK. Therefore, combination of DSK and the antenna pattern diversity reception seems to be a promising candidate for high speed mobile data transmission system.
4. Multipath delay profiles were measured at various locations in Kyoto and general characteristics were clarified. The major causes of long delay were identified. The relation between delay time and error rate was analyzed and it was found that error rate never fell below 10^<-3> and got degraded up to 10^<-1> if long delayed signals existed at data rates above 50-100 kbps for ordinary modulation schemes.
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