Transmission system for satellite ISDB

A new digital satellite broadcasting service will start in the year 2000 in Japan. The technical standard for the transmission system has been established. The standard has been developed based on the studies of ISDB (integrated services digital broadcasting), which aims at broadcasting of “any information accessible at any time” and allows not only audio and video services but also every types of new services by flexibly integrating the information to be broadcast. The system provides large capacity which is sufficient to transmit two HDTV programs in one satellite channel, strong robustness against heavy rain-fall attenuation and high operational flexibility. One of the key techniques of the system is hierarchical modulation, in which multiple modulation schemes can be applied simultaneously. An information bit rate of 52 Mbps is obtained in one satellite channel by applying TC8PSK (trellis-coded eight PSK) and a low C/N reception at 2 dB is achieved by applying BPSK. The system can also handle multiple MPEG2-TSs (transport streams) by employing a frame structure. Broadcasters have their own MPEG2-TS in which they can integrate their services independently of each other, even when they share a satellite channel