Satellite broadcasting: Protection ratio requirements for enhanced transmissions using extended PAL vision and digital sound signals

Experiments with signals for satellite broadcasting to demonstrate the possibilities of enhancement to both vision and sound were conducted. The resultant signal has a different spectrum from that of a conventionally coded signal. Thus it is necessary to examine interference protection ratios for the enhanced signal and determine any differences from those assumed in the WARC satellite broadcast plan. The interference effects of, and the protection ratios required by, an enhanced signal comprising an extended PAL video signal and a digitally modulated sound subcarrier are considered. It is shown that the protection ratios assumed in the WARC plan are not infringed.