Methods for accommodation of HDTV terrestrial broadcasting

In the United States, consideration is underway to provide for the terrestrial emission of high-definition television (HDTV) signals in the existing VHF/UHF allocations. Analyses show that it may be necessary to reduce cochannel spacings to a minimum of 160 km if the vast majority of existing terrestrial broadcasters are to be accommodated with an HDTV service in addition to their NTSC capability. HDTV coverage and acceptable cochannel interference levels of these spacings are under investigation. Techniques that determine if there is sufficient spectrum to provide for the additional services are described. The techniques include assessments of the need to maintain UHF taboo restrictions currently applied to NTSC, analysis of effective coverage areas, and development of allotment/assignment methodologies