Sending for sending a videofrekvent television signal using a frequency-modulated wave and receiver for reception of the transmitter's broadcast signal.

摘要

991,643. Frequency modulation. COMPAGNIE FRANCAISE DE TELEVISION. Oct. 17, 1961 [Oct. 28, 1960], No. 37266/61. Drawings to Specification. Heading H3R. A frequency-modulated wave is passed through a filter attenuating the carrier and central frequencies relatively to the other side frequencies, before transmission, to improve signal to noise ratio at the receiver. A complementary filter at the receiver restores the correct relative amplitudes before demodulating the wave. The modulation may be a colour television chrominance signal, or a pair of such signals transmitted sequentially, and frequency modulating a subcarrier. The filtering at the transmitter or receiver need not be at the transmitted or received carrier frequencies but at a transposed frequency. Pre-emphasis may be applied to the modulation. The FM wave may be part of a colour television composite video signal, transmitted by cable between a transmitter and receiver.