45-Mbps multichannel TV coding system

A new digital coding system is presented, which makes it possible to transmit up to 4 NTSC TV programs simultaneously over a single DS3 45Mbps link including two high-quality sound channels and one 64 kbps ancillary data channel. The principal bit-reduction technology employed is 2-dimensional intraframe WHT (Walsh Hadamard Transform) coding with an advanced adaptive quantization reflecting human visual perception. The hardware has been made compact like a home use VTR.