An Extended Definition Television System Using Quadrature Modulation of the Video Carrier with Inverse Nyquist Filter

A QUadrature Modulating Extended definition television system -QUME- , which enhances NTSC to higher definition , is proposed. The QUME system uses quadrature modulation of video carrier with inverse nyquist filter and creates an independent transmission channel (Bandwidth : 1MHz) without using additional channel resources. One of the features of QUME is that the multiplexed signal hardly interferes with the conventional TV receivers, and another is that there is no crosstalk between the multiplexed signal and the main NTSC signal. These features enable a wide aspect ratio image to be transmitted as well as high frequency components of luminance and/or chrominance signals, while keeping compatibility with the NTSC system.