Collaborative Research Depertment

Communication, United States

Collaborative Research Depertment

Communication, United States
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Satoh M.,Collaborative Research Depertment | Orikasa T.,Wireless Network Research Institute | Fujino Y.,Wireless Network Research Institute | Fujino Y.,Toyo University
Journal of the National Institute of Information and Communications Technology | Year: 2014

ETS-VIII was equipped with the Large Deployable Reflector Antenna(LDRA) for land mobile communications. This paper describes the electrical performances of that antenna. We measured signal level of radio wave from LDR at some ground receiving stations. This result is daily variation of receiving level and precipitous variation during the satellite-eclipse. We considered this phenomenon was caused by thermal distortion of reflector. We made correct the antenna beam position and measured the receiving level for improvement of this variation.


Yamamoto S.-I.,Wireless Network Research Institute | Kawasaki K.,Wireless Network Research Institute | Satoh M.,Collaborative Research Depertment
Journal of the National Institute of Information and Communications Technology | Year: 2014

We carried out the multicast communication experiment for mobiles using the Engineering Test Satellite VIII (ETS-VIII). In communication experiment, we measured the transmission characteristics in the case that OFDM signal passed through the satellite link with a non-linear characteristic, and confirmed the effect on the transmission characteristics due to non-linear link of the multi-carrier constituting the OFDM signa.


Taira S.,Wireless Network Research Institute | Satoh M.,Collaborative Research Depertment | Yamamoto S.-I.,Wireless Network Research Institute
Journal of the National Institute of Information and Communications Technology | Year: 2014

The Engineering Test Satellite VIII has onboard equipments for the mobile satellite communications system using S-band frequency. The data transmission test for the aeronautical mobile satellite communication was carried out using the Engineering Test Satellite VIII. The test results showed that the throughput performance in the case of the level flight was almost as same as that in the case of the static condition, and that in the case of the 20 degrees turning flight was about 2 dB less than that in the case of the static condition.


Orikasa T.,Wireless Network Research Institute | Satoh M.,Collaborative Research Depertment | Yamamoto S.-I.,Wireless Network Research Institute | Kawasaki K.,Wireless Network Research Institute | And 2 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2014

The reflectors of large antennas of equipped on communication satellite are very complex and radiation pattern of antenna can be affected by surface error and distortion. With these large antennas, thermal distortion error especially can have serious implications, causing orbit beam direction errors, distortion of beam shapes, and increasing sidelobe levels. This chapter describes the experimental results with the REV (Rotating element Electric field Vector) method measured at multi earth stations using ETS-VIII (Engineering Test Satellite VIII) and we verified the evaluation of limited reflector information (rotation) for correction of weight of array elements and radiation pattern.

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