Isdb-S - Satellite Transmission System For Advanced Multimedia Services Provided By Integrated Services Digital Broadcasting

A new digital satellite broadcasting service will start in Japan in the year 2000. The technical standard for the transmission system has been established. This service is based on ISDB (Integrated Services Digital Broadcasting), which aims to broadcast "any information accessible at any time" and provide not only video and audio services but also new multimedia services by flexibly integrating the information to be broadcast. The system can 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. It also provides a large capacity sufficient to transmit two HDTV programs on one satellite channel, robustness against heavy rain-fall attenuation, and high operational flexibility. One key feature of the system is hierarchical modulation, in which multiple modulation schemes are applied simultaneously. That is a information bit rate of 52 Mbps in one satellite channel is obtained by applying TC8PSK (Trellis-Coded eight PSK) and a low C/N reception at 2 dB is achieved by applying BPSK.