Maximum transmission bit rate for satellite ISDB and its application in a satellite broadcasting plan

ISDB (integrated service digital broadcasting) is investigated as a flexible broadcast system for the future. This paper discusses a transmission system for satellite digital broadcasting, based on this concept. The purpose is to provide inputs for the reconsideration of the 12-GHz satellite broadcast plan presently promoted by ITU-R. As the first step, we propose a method of determining the optimal parameters of the transmission system. A new parameter is defined, namely, the normalized EIRP, combining EIRP of the satellite and the transmission bandwidth. Then the relations among the service availability, the transmission capacity, and the transmission system, which is the key to the satellite broadcast system, can be derived in general form. Assuming the use of QPSK + convolutional code, as well as TCM8PSK, the actual satellite channel model is defined. Detailed investigations are made by simulation, and the transmission system that maximizes the transmission rate is determined, along with the normalized transmission rate. The following results are obtained. In the case of such a satellite with a high EIRP, as currently in the Japanese broadcast satellites, TCM8PSK is better when the worstcase monthly availability is less than 99.7 percent; and QPSK + convolutional code is better when an availability above 99.9 percent is required. For a satellite with a low EIRP, QPSK + convolutional code is better. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 1, 80 (5): 76–87, 1997