Abstract: The present invention is directed to a home automation system, wherein a coaxial cable or other home bus path for data transmission is placed inside a home to connect an intercom unit and monitor camera, which comprise a hardware interface for communication with visitors, and a conventional home television to this bus, thereby to make it possible to output the audio and video signals from the intercom unit and monitor camera on a conventional broadcast reception television.

Abstract: A ghost cancelling reference signal transmission/reception system, which allows a built-in ghost cancelling device to eliminate group-delay distortion, frequency-amplitude characteristic distortion, ghost components generated in a signal transmission path. A digital signal is superposed on a television signal in a vertical blanking period of the television signal as a ghost cancelling reference signal.

Abstract: In a transmission system of signals including amplitude-modulated television signals, a pilot signal of a specific amplitude is supplied at a first place in the transmission system, and at a second place in the transmission system, the pilot signal having been subjected to a cross modulation due to nonlinearity of the transmission system from the first place to the second place is extracted. A rectifier picks up an envelope of the cross modulated pilot signal. In consequence, out of the envelope, the fundamental wave component or a higher harmonic component of the horizontal scanning frequency of the transmitted television signal is extracted by using a filter of an extremely narrow band. By detecting the increase in the level of this removed signal, an increase in distortion due to an excessive level of the transmission signal which causes a problem in the transmission system is detected.

Abstract: A digital data reproducing system which carries out quantization by the frequency over the transmission rate with respect to waveform distortion created by a group delay caused by ghosts and repeaters or the like when digital information signals are received so as to thereby perform waveform equalization, and which carries out phase correction to thereby enable data reproduction about equivalent to that quantized by an ideal sampling timing, thus realizing entire digitization of the data reproducing system.

Abstract: A ghost canceling apparatus for effectively canceling ghosts in television signals and having a high capability for canceling ghosts in the frequency band in which the ghost canceling is required. The apparatus utilizes an error detector and a tap gain control in a closed loop to control the gain of a transversal filter. In addition, a frequency transfer characteristic modifier is utilized to modify the loop frequency transfer characteristics so as to optimize the cancelation of ghosts.

Abstract: The present invention is directed to a home automation system, wherein a coaxial cable or other home bus path for data transmission is placed inside a home to connect an intercom unit and monitor camera, which comprise a hardware interface for communication with visitors, and a conventional home television to this bus, thereby to make it possible to output the audio and video signals from the intercom unit and monitor camera on a conventional broadcast reception television.