Extended horizontal resolution of luminance and chrominance in a high definition television system

Method and apparatus for extending the horizontal resolution of the luminance and chrominance video signals in a two-­channel HDTV system, requiring no increase in channel bandwidth. High-­frequency components of luminance and chrominance of a wide bandwidth source signal are bandpass filtered, vertically decimated, time expanded, and heterodyned into frequency interleaved relationship with each other and with a line differential signal to produce and enhancement package carried in a designated time and frequency slot on the second channel. At the the receiver, the various signal components are recombined to substantially reproduce the source signal for display.