ABSTRACT
This chapter addresses the question: What will be required in transmitter facilities to handle the fundamentally digital transmissions. The shorter spacing requires that the high definition television (HDTV) signals both cause less interference into NTSC signals and be less subject to interference from NTSC signals than would an NTSC signal in the same location with the same coverage area. Such interference avoidance is accomplished in three principal ways: noise-like signals, low power transmission, and leveraging NTSC characteristics. Both advanced digital HDTV (AD-HDTV) and Narrow multiple sub-nyquist sampling encoding (MUSE) avoid placing significant energy in the regions around the NTSC visual or aural carriers. All of the systems just mentioned take advantage of the Nyquist slope in the NTSC receiver IF filter that compensates for the presence of both sidebands in the lower video frequencies. NTSC transmission technology is good enough to carry HDTV—with careful handling.
