抄録
We have developed a DAVIC 1.0 based 256QAM modulator/demodulator. An experimental result of their IF and RF signal transmission with noise in a transmission line is described. C/N of more than 32.5dB is required to keep BER of less than 1×10^<g;-4> without forward error correction. This result indicates that about 7dB better C/N is necessary to achieve same performance than that of 64QAM transmission.