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the output power of the HPA in the ground station is 48.0 dBm. e received spectrum does not show signicant change due to the DPD. is is because the re-growth component reduced by the DPD is covered by thermal noise. On the other hand, the received constellation allows the conrmation of the eect dissolution of the power compression and the phase rotation in the communication path by the DPD. e comparison of the result (Fig. 6: blue solid line) aer applying the DPD, obtained in the satellite loopback path, and the result of the translator loopback (Fig. 6: green solid line) gave the result that the dierence from the required Eb/No at the BER requirement of 5 × 10-4 before decoding the error-correcting required by the satellite system is small, about 0.4 dB, and that the DPD application allows the transmission loss in the satellite communication path to become smaller.5SummaryIn this experiment, we intended to improve the degra-dation of the transmission characteristics which arise due to the non-linear distortion of the power amplier existing in the satellite communication path with the DPD technol-ogy assuming the satellite on-board. As the experimental result, we could experimentally conrm that the DPD using one LUT eectively compensated the non-linearity existing in the satellite communication path and that the transmis-sion characteristics could be improved. Furthermore, we claried that the consideration of the degradation of the transmission characteristics due to the power variation of the transmitter and the variation of the amplier could reduce the frequency of update of the LUT, and that only correcting the LUT to give the received constellation an optimal allocation allowed the LUT to be easily updated. erefore, this is practically a powerful method.AcknowledgmentsWe received much support from NICT and the relevant departments of JAXA for this experiment. Particularly, we received brotherly support from Takashi TAKAHASHI, the director of the Kashima Space Technology Center, Space Communication Laboratory, NICT Wireless Networks Research Center, Tomoshige KAN, a researcher, and Toshio ASAI. We would like to take this opportunity to thank everyone.ReferenceR1M. Yajima, M. Nakadai, Y. Tashima, N. Ando, S. Tani, and A. Fujimura, “Perfoemance Evaluation of Ka-band Satellite Communication Subsystem Using a Digital Pre-Distorter,” 7th ESA International Workshop on Tracking, Telemetry and Command Systems for Space Applications, Sept. 2016.2Y. Tashima, K. Inaoka, M. Yajima, N. Ando, S. Tani, and A. Fujimura, “Performance Evaluation of a Ka-band Satellite Communication Subsystem Using Pre-distortion Techniques,” AIAA International Communications Satellite Systems Conference 2015, Sept. 2015.3HASHIMOTO Yukio, TAKAHASHI Takashi, and YOSHIMURA Naoko, “Earth Stations for WINDS High-Speed Network,” Special Issue on Wideband InterNetworking Engineering Test and Demonstration Satellite (WINDS), Journal of NICT, vol.54, no.4. pp.65–70, 2007.4http://www.zodiacaerospace.com/en/products-services/aerosystems/data-sys-tems/space-applications/earth-observation-remote-sensing/cortex-hdr-xxl-high-data-rate-receiver, June. 26,2017.Mitsuhiro NAKADAI Researcher, Research Unit I Research and Development DirectrateSatellite communication, Wideband communicationMasanobu YAJIMA Manager, Research Unit I Research and Development DirectrateSatellite communication, Array antenna3 Ultra-High-Speed Satellite Communication Technology150　　　Journal of the National Institute of Information and Communications Technology Vol. 64 No. 2 (2017)