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ment of the equalizer coecient is required. However, because the frequency bandwidth for each frequency can be narrowed with OFDM, these eects can be reduced.3WINDS satellite communication experiment: Uncompressed 4K UHDTVFigure 6 shows an overview diagram of the WINDS satellite communication experiment. A satellite communi-cation experiment was conducted using a large-scale in-vehicle earth station with a 2.4 m antenna in the earth station. Furthermore, digital clipping by CF (Clip and Filtering) (9 dB Back O) is being conducted in the FPGA on the earth station transmitting side that prevents exces-sive input to the satellite. ere are also no problems in the analog limit because the point of saturation of the output of the ground transmitter is lower than the point of exces-sive input to the satellite.Figure 7 shows the received signal frequency spectrum through the WINDS satellite. Figure 8 shows the I/Q constellation of each of the 16 frequencies when demodu-lating. Because of dierences in the Es/No for each wave-length due to the eects of the transponder’s amplitude-frequency characteristics, dierences in de-modulation characteristics were observed. However, all 16 frequencies were demodulated normally. e bit error rate before correction was 6.12×10-3. A quasi-error-free (BER < 1.0×10-11) line was achieved by applying LDPC error cor-rection. Figure 9 shows the I/Q constellations of the f12 subcarrier of 16APSK and 16QAM when Eb/No is 14.5 dB. 16QAM conrmed that BER before error correction is improved compared to 16APSK. Figure 10 shows the measurement results of 16 APSK-OFDM and 16 QAM-OFDM BER characteristics measured again under a good FiF7　Received signal frequency spectrum (12 March 2014)FiF8　I/Q constellations (12 March 2014)16QAM-OFDM(f12) BER=9.82×10-316APSK-OFDM(f12) BER=8.30×10-3Eb/No=14.5[dB]FiF9　f12 I/Q constellations (6 Nov. 2014)3 Ultra-High-Speed Satellite Communication Technology114　　　Journal of the National Institute of Information and Communications Technology Vol. 64 No. 2 (2017)