A system for transmitting a modulated video signal to be presented on a digital display device, the video signal having a first frame and a second frame, the first frame and the second frame each comprised of a plurality of pixels, the system comprising a signal source for generating a video signal, an encoder, the encoder comprising a means for receiving the video signal from the signal source, a means for selectively altering luminance of the pixels of the first frame and the second frame of the video signal to represent a signal presence or signal absence and thereby creating a modulated video signal, and a means for providing the modulated video signal to a broadcast source, and the broadcast source for providing the modulated video signal from the encoder to a digital display device.