Ghost-canceling reference

Abstract: A ghost canceling reference signal transmission and reception system utilizes a ghost canceling reference signal including a zero to seventy IRE step followed by a seventy to zero IRE (sin x)/x step.

Abstract: A multiplex TV signal processing apparatus in a television signal transmitting and receiving system includes an apparatus at the transmitting side which has a first amplitude-modulator for modulating a first carrier by a main signal to obtain a vestigial side-band amplitude-modulated main signal; a second amplitude-modulator for modulating a second carrier but whose frequency is the same as which phase is 90 degree different from the first carrier by a sub signal to obtain a carrier suppressed amplitude-modulated signal; a first inserter for inserting a first ghost canceling reference signal into a horizontal line of the main signal during a vertical blanking period; a second inserter for inserting a second ghost canceling reference signal into the same horizontal line of the sub signal as the first ghost canceling reference signal; and includes an apparatus at the receiving side which has: a first demodulator for demodulating the main signal; a second demodulator for demodulating the sub signal; a ghost canceler for canceling a ghost of the sub signal using the second ghost canceling reference signal; and a crosstalk canceler for canceling the crosstalk of the sub signal from the main signal using the first ghost canceling reference signal

Abstract: A system that utilizes a reference signal for testing signal paths for complex frequency response (linear distortion), and non-linear distortion. This reference signal, which is also known as a ghost canceling reference signal or a training waveform, has excellent properties for channel characterization. The reference signal is a waveform that operates for a major time interval that is subdivided into multiple minor time intervals. During each minor time interval, a sine wave oscillates at a constant angular velocity or frequency. The sine wave frequency may take uniform steps between the minor time intervals, or it may skip a group of frequencies. The phase of the waveform may optionally be continuous between the end of one minor time interval and the start of the next minor time interval. This waveform is generated by loading the time sample values from a digital memory into a digital to analog converter (D-A), or by rapidly reprogramming a numerically-controlled oscillator. The reference signal can also be analyzed for the presence of non-linear distortion. Broadband RF channels, such as cable television channels, or baseband channels, such as telephone channels may be characterized using this waveform.

Abstract: An apparatus for removing a ghost component which disturbs a picture signal by means of a ghost canceling reference signal included therein. The reference signal is extracted from the picture signal and judged as to whether it has a specific level in a reference time interval. The extracted reference signal is also judged as to whether a color burst signal is canceled. If both judgments are positive, a judgement signal is generated which allows the extracted signal to be examined how it is disturbed by the ghost component. In response to the examination, the ghost component is removed from the picture signal.