Title:
MULTIPLEX TRANSMISSION METHOD AND TRANSMITTER-RECEIVER THEREFOR
Document Type and Number:
Japanese Patent JPH02156786
Kind Code:
A
Abstract:
PURPOSE:To reduce disturbance between multiplex signals by measuring the degree of deterioration of the transmission line characteristic from its ideal state up to a receiver for a period of a reference signal sent by a transmission line characteristic detection circuit provided to the receiver and controlling a waveform equalizing circuit in response to the measurement so as to correct the transmission line characteristic. CONSTITUTION:The transmitter-receiver is provided with a waveform equalizing circuit 19 providing a reference signal able to separate the disturbance of a video signal and a multiplex signal into a multiplex transmission signal and correcting the deterioration in the transmission characteristic in the receiver, a reference signal period detection circuit 17 detecting the transmission timing of the reference signal, and a transmission line characteristic detection circuit 18 analyzing the waveform of the reference signal in the input signal or the output signal of the waveform equalizing circuit 19 and measuring the deterioration in the transmission line characteristic. Since the reference signal sent from a broadcast station is definite and the signal waveform with an idealistic transmission line characteristic is know, the received waveform of the reference signal is caught, the degree of the deterioration in the transmission line characteristic is measured to correct the waveform. Thus, the transmission line characteristic approaches the ideal state and the disturbance between signals sent multiplexedly with orthogonal modulation is reduced.
Inventors:
NODA TSUTOMU
KISUGI TAKATOSHI
MURATA TOSHINORI
INMI MASABUMI
ITO SHIGEFUMI
KISUGI TAKATOSHI
MURATA TOSHINORI
INMI MASABUMI
ITO SHIGEFUMI
Application Number:
JP30995988A
Publication Date:
June 15, 1990
Filing Date:
December 09, 1988
Export Citation:
Assignee:
HITACHI LTD
International Classes:
H04N7/08; H04J11/00; H04N7/081; H04N7/083; H04N7/087; H04N7/088; (IPC1-7): H04J11/00; H04N7/08; H04N7/087
Attorney, Agent or Firm:
Katsuo Ogawa (1 person outside)