抄録
Narrow-band ISDB-T(Integrated Services Digital Broadcasting for Terrestrial) has been adopted as Japan's standard terrestrial digital audio and data broadcasting system in November 1999. Its transmission scheme is BST-OFDM(Band Segmented Transmission - Orthogonal Frequency Division Multiplexing). There are two kinds of bandwidths : a single 429 kHz segment and about 1.3 MHz for three-segments transmission. The system performance was tested using Tokyo Tower experimental station for the DSB(Digital Sound Broadcasting) standardization process in Japan. Test signals are broadcasted at the power of 100W over a VHF channel with a center frequency of 190 MHz. The received field strength and bit error rate were measured along highways and main roads within 80 km of the tower. The necessary field strength was 38 dBμV/m when each OFDM carrier was modulated by DQPSK and was 44 dBμV/m when each OFDM carrier was modulated by 16QAM. It has been verified that the narrow-band ISDB-T is sufficiently robust against multi-path and fading interference and services for mobile receivers are available.
