1989 Fiscal Year Final Research Report Summary
Speeding up of Digital Transmission Rate over the Mobile Radio Channel
| Project/Area Number |
62550234
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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 | Gunma University |
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Principal Investigator |
MORINAGA Takahiro Gunma University, Dept. of Elec. Eng., Professor, 工学部・電気電子工学科, 教授 (20111396)
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| Co-Investigator(Kenkyū-buntansha) |
HORIKOSHI Jun Gunma University, Dept. of Elec. Eng., Associate Professor, 工学部・電気電子工学科, 助教授 (10008477)
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| Project Period (FY) |
1987 – 1990
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| Keywords | Radio Communications / Digital Mobile Radio / Multipath Interfering / Frequency Selective Fading / Fading / CPFSK / Continuous Phase FSK / Adaptive Equalization |
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| Research Abstract |
In this research, we have investigated in those themas described below.
1 . To clarify the error probability characteristics of GMSK in the multipath interfering mobile radio environments. GMSK is selected because it is the well-known modulation-demodulation scheme among many CPFSK systems. It has been clarified that degradation of BER characteristics of the CPFSK is very large in the frequency selective fading channel. These results have dealt as the standard characteristics in discussing BER characteristics of other systems.
2. To analyze error rate of pi/2-TFSK in the multipath interfering mobile radio channel. The pi/2-TFSK has proposed by one of our researching team.It is clarified that BER characteristics under a band-limited condition(raised cosine type transmitting lowpass filter and the Gaussian type receiving BPF being assumed) is superior to that of GMSK and MSK. So it is concluded that pi/2-TFSK shows a better BER characteristics in the multipath interfering mobile radio channel. Consequently, we are able to transmit digital signal at a higher bit rate by using pi/2-TFSK compared with MSK in the multipath interfering environments.
3.Hardware simulation at 800MHz has been undertaken in the laboratory for the above themas. A modulator is implemented with a quadrature-modulation type. A 2-bit differential detection is applied to demodulate the information. The delaying wave is realized in the baseband stage. We are now still in adjustment in these days for the band-limited-type equipment. In the other hand, the results of analysis has been well coincided with the measurements for the idealized unlimited condition.
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