Study of Factors Affecting an HF/VHF Direct Broadcasting Satellite Service

The Institute for Telecommunication Sciences has undertaken an assessment of the link margin required for the satisfactory performance of a direct broadcasting satellite service operating in the high frequency (HF) and in the very high frequency (VHF) bands. The assessment involved the determination of a number of issues relating to performance of HF and VHF satellite-based transmission systems. These issues included determining under what conditions a frequency allocated to the broadcasting service can be expected to reach the surface of the Earth from a satellite, the loss of signal strength due to passage through the ionosphere, the impact of sporadic E and ionospheric ducting, the effect of scintillation on broadcast performance, the impact of Faraday rotation on system design, and the possibility of a satellite-based broadcasting service interfering with existing ground-based services. In this report, the results of this study are presented.