Video channels characterization for advanced television

Some of the video channel characteristics needed to evaluate the effect of over-the-air and cable transmission channels on conventional or advanced television (ATV) signals are presented. Field measurements were performed by the Communications Research Centre to evaluate the performance of the Canadian teletext system. The expected performance for the digital part of an ATV transmission system is indicated. Over-the-air reception was shown to be very good except at 10% of the sites in urban areas and 25% of those in hilly areas. Cable distribution gave good results if the signal at the head-end was not distorted. Adaptive equalization should improve marginal sites. Additional data collected during the field tests can be used to reproduce video channel characteristics in the laboratory