A high definition television system to provide an efficient use of bandwidths, derives from a high definition television source signal, composite main signals and composite line differential signals. These signals are divided into main center components and main panel components and line differential center components and line differential panel components. The line differential center components and main center components are then quadrature modulated and transmitted as a vestigial sideband signal over a first transmission path. The main panel components and the line differential panel components are quadrature modulated and formed into a vestigial sideband signal which is then time multiplexed with the high frequency luminance signal forming a time multiplexed signal. The time multiplexed signal is then frequency multiplexed with a digital sound and synchronization signal in order to form an augmentation signal which is transmitted over a portion of a second transmission path.