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Predecessor
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Displaying 1-8 of 8 articles from this issue
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Article type: Cover
Pages Cover1-
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (13K) -
Article type: Index
Pages Toc1-
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (31K) -
Hiroki OHTA, Yoneo AKITA, Makoto ITAMI, Aiichiro TSUZUKUArticle type: Article
Session ID: ROFT'99-54
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe Digital Terrestrial Television Broadcasting(DTTB)will start in 2000 in Japan. In the DTTB, the Orthogonal Frequency Division Multiplex(OFDM)is used. The OFDM is brand new technology, then many kind of in-door tests and verification tests in field are carried out to realize DTTB. But the time schedule was very tight, so some tests are omitted. To shorten the period of development, we have made a programmable signal processing system using CPU and Field Programmable Gate Array(FPGA)that controlled by Graphical Use Interface(GUI). In this paper the outline of the programmable signal processing system is mentioned, and some examples applied for the OFDM are also described.View full abstractDownload PDF (1326K) -
Toru Abe, Shoichi NochiArticle type: Article
Session ID: ROFT'99-55
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe developed space diversity communication control unit, which has non-cutoff function for QPSK digital radio receiver(SHF band). This system has good stability, high-speed detection, and switch-over with low level of receive signal and degradation of BER(Bit Error Rate). It is found to be useful for oversea propagation and frequent heavy fading of microwave digital communications line. Also, this system design realizable low transmission power and low cost.View full abstractDownload PDF (716K) -
Taro Teramoto, Takahiro Shima, Makoto Itami, Hiroki Ohta, Kohji ItohArticle type: Article
Session ID: ROFT'99-56
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn this paper, we discuss about diversity reception of an OFDM signal using pilot symbol assisted channel estimation. We usually use an adaptive equalizer in an OFDM demodulator to improve the effect of multipath interference and the frequency selective fading. In an OFDM demodulator, the equalization technique in which the received symbol is divided by the channel transfer function, has been discussed. However, when the absolute value of the channel transfer function is very small because of the frequency selective fading, the performance will degrade by an additive noise. So, we propose diversity reception of an OFDM signal using pilot symbol assisted channel estimation, which is effective to improve the bit error rate characteristic under multipath environments. As the results of computer simulations and theoretical analyses, it is confirmed that the bit error rate characteristic is better than the single antenna receiver.View full abstractDownload PDF (601K) -
Toru nakamura, Makoto Itami, Hiroki Ohta, Kohji ItohArticle type: Article
Session ID: ROFT'99-57
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAn Orthogonal Frequency Division Multiplexing(OFDM)is one of the multicarrier moduration schemes. Its signal is made of a lot of synthesized data which is divided into orthogonally arranged carriers in frequency axis. As carriers are orthogonal to each other, it is possible to use frequency band efficiently. And OFDM is not much affected by multipath interferences because its symbol length can be made very long, and inter-symbol interference is eliminated by adding a guard-interval part to the OFDM symbol. In a Single Frequency Network(SFN)environment, a multipath is usually exists and the charactristic of rception of OFDM signal is affected. In mobile reception of OFDM signal, it is very serious. In this paper, the characteristic in mobile reception of OFDM signal under SFN environment are theoretically analyzed.View full abstractDownload PDF (661K) -
Ichirou IDA, Jin SATO, Koichi ITOArticle type: Article
Session ID: ROFT'99-58
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe performances of the small dielectric antennas(DLAs)were evaluated using the FDTD method. The efficiency-fractional bandwidth(EB)product was used as a criterion of the evaluation. When applied to electrically small antennas, the EB product is equivalent to the PF proposed by Wheeler and easy to confirm by calculation and experiment. Several shapes of DLAs with almost the same volume were compared with a bare dipole using the EB product. The EB products were calculated both numerically and experimentally. As a result, it was found that the cylindrical DLA with relatively lower permittivity(ε_r less than about five)gives enhancement of the EB product over the bare dipole. This indicates the existence of the optimum values and shapes of dielectric loading to obtain the highest EB product.View full abstractDownload PDF (390K) -
Article type: Appendix
Pages App1-
Published: May 21, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (84K)
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