Field transmission experiments using relay transmitter for digital terrestrial broadcasting were carried out by ARIB in winter, 1999. This paper describes the results of the field experiments. In each relay station, the signal was degraded due to a coupling from transmitting antenna to receiving antenna. If 64QAM-OFDM with coding rate of 7/8 is the case of relay, the amount of C/N degradation can be held down to 2.0dB or less with securing 15dB or more of return D/U.
