| Project/Area Number |
04555075
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| Research Category |
Grant-in-Aid for Developmental 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 | TAKUSHOKU UNIVERSITY |
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Principal Investigator |
IKEGAMI Fumio TAKUSHOKU UNIVERSITY,FACULTY OF ENGINEERING PROFESSOR, 工学部, 教授 (20093180)
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| Co-Investigator(Kenkyū-buntansha) |
FUJINO Tadashi MITSUBISHI ELECTRIC CORPORATION,MANAGER, 無線伝送開発部, 部長
SHIRAHARA Kunihiko MITSUBISHI ELECTRIC CORPORATION,MANAGER, 通信機第一部, 部長
HASHIMOTO Kozo TOKYO DENKI UNIVERSITY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (80026369)
KAKEUCHI Tsutomu KYOTO SANGYO UNIVERSITY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (20154974)
YOSHIDA Susumu KYOTO UNIVERSITY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (50026324)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Mobile message communication / Packet error rate / Error-free transmission propability / Bit-by-bit error / Error structure |
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| Research Abstract |
Mobile message communication of high transmission bit rate can be a candidate for the ULTIMATE COMMUNICATION as it has merits of very low cost and very high radio spectral efficiency and moreover it does not invade human privacy. Analyzes on spatial probability of error-free transmission has been made by simmulated laboratory experiments and field tests. The following results are obtained :
(1) General characteristics of bit/packet error rates and error-free transmission probability have been made clear for various propagation and system parameters. A use of anti-multipath modulation PSK-RZ is found inevitable for the purpose.
(2) A new concept of SPECIFIC TRANSMISSION TIME defined as a normalizing parameter for bit error rates enabled to make evaluation of packet error rates easier.
(3) When PSK-RZ is effective, more than 99% of error-free probability can be easily obtained for proper values of CN ratio.
(4) The occurrence mechanism and fine structure of errors were analyzed by a newly developed bit-by-bit error measurements. Occurrences of burst errors are limited to the points in the vicinity of deep fade, and error-free transmission is easily attained at other points.
(5) In case PSK-RZ is not effective, burst errors due to desynchronization disappear in a moment of msec, and error-free probability of 70% may be obtained for the worst condition. By retransmitting the signal, about 90% of probability is assured.
(6) To make error-free transmission easier, circular polarization and polarization diversity effects, reduction of fading and error rates using directional antenna have been studied experimentally.
Combining the above results, realization of mobile message communication seems hopefull.
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