Abstract: A system for equalizing an input signal including a datastream modulated on a carrier, with respect to both transmission channel distortions and local receiver distortions, includes a network for frequency downshifting the input signal, a controlled non-recursive filter (20) responsive to the downshifted input signal, and a demodulator (30) for receiving an output signal from the controlled filter. A signal processing network, including a filter network with a transfer function (40, 60, 80, 100) which is the inverse of the transfer function of the controlled filter, responds to an output signal from the demodulator for producing output control signals. The control signals are coupled to a coefficient control input of the non-recursive filter for equalizing the signal with respect to both transmission channel and receiver distortion.

Abstract: In a method of transmitting digitally coded information in a television sound channel, the digitally coded information is inserted on an existing frequency-modulated RF sound carrier as a channel-coded signal above the television audio-frequency base spectrum in the base band. The modulation amplitude is selected so that disturbances during reproduction of the television sound are excluded in the receiver. The spectrum of the channel-coded signal is evenly distributed over the available frequency range using a pseudo-signal during modulation intervals. The clock frequency of the channel-coded signal is coupled with the line frequency.

Abstract: A television transmission system compatible with current television standard includes a compatible wide aspect ratio television signal containing vacated spatial areas along upper and lower edges of an image defined by lines remaining after lines are separated from groups of successive lines within an image scanning interval. The separated lines are inserted into the vacated spatial areas. A first carrier is modulated with non-active portions of the separated lines, and with the remaining lines. A second carrier is modulated with time expanded active image portions of the separated lines, and is disposed in an upper portion of the television signal frequency spectrum so as to be suppressed in a standard aspect ratio receiver.