Method for transmitting spectrum-compatible high-definition television signal and circuit therefor in a television signal transmission system

A method for transmitting spectrum-compatible high-definition television signals in a television signal transmission system, comprising:

• separating digital luminance and chrominance signals into a low frequency band signal and a high frequency band signal;
• detecting a motion vector from the low frequency band signal;
• processing said high frequency band signal in response to the motion vector to create a processed high frequency band signal;
• converting said low frequency band signal into a first analog signal through a first low-pass filtering, said low frequency band signal being delayed by a given time duration and added to said motion vector;
• converting the processed high frequency band signal into a second analog signal through a second low-pass filtering;
• and
• multiplying the outputs of said the first analog signal and the second analog signal by a first sinusoidal signal and a second sinusoidal signal, respectively, and synthesizing the first analog signal and the second analog signal to produce a transmission signal.

A circuit for generating narrow bandwidth high-definition television signals, the circuit comprising:

• band separation means for separating a digital signal into a low frequency signal and a high frequency signal;
• motion vector calculation means for calculating a motion vector signal from the low frequency band signal;
• high frequency signal processing means for generating a processed high frequency signal by processing the high frequency signal in response to the motion vector signal;
• first adding means for adding the low frequency band signal to the motion vector signal and generating a low frequency/motion signal.