Abstract: A component television signal is transmitted as a sequence of television frames with each frame having a plurality of television lines substantially all of which have first and second time multiplexed portions. The first portion (DB) forms the data burst and conveys sound/data information in digital form at a given bit rate while the second portion of each line outside the vertical blanking intervals (VBI) conveys vision information (U/V, Y). The second portion of at least some of the lines in the verical blanking intervals (VBI) convey additional information in digital form at a higher bit rate than the given bit rate and which may be twice the given bit rate. This additional information can be the digital channel information for a digitally assisted television signal.

Abstract: A wide-band frequency modulated DBS signal of the type having time sequential compressed chrominance and luminance (video) components is received by an aerial (1), frequency converted in a down converter (2) and applied to the input (4) of a conversion unit. The conversion unit has a tuner (5), i.f. stage (9,10) and a frequency demodulator (11) to produce baseband video which is applied after de-emphasis at (12) to a modulator (27) where the video is amplitude modulate onto a vision carrier from an oscillator (28). The modulated carrier is applied through a vestigial sideband filter (29) and an adder (30) to an output (31). Sound/data bursts present in the DBS signal are recovered in a stage (13) and processed in a processor (14) where the sound/data bursts are expanded to occupy approximately a line period at a bit rate which is an integral sub-multiple of the bit rate for the sound/data bursts in the received DBS signal.