UP SIGNAL CONTROL SYSTEM FOR CATV

PROBLEM TO BE SOLVED: To solve the problem of a conventional two-way digital CATV system that needs a cost of QPSK modulators for a head end system and QPSK demodulation circuits for receivers because all the receivers of the system have always to receive the same downward control signal in order to...

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Bibliographic Details
Main Author MOROTOMI TETSUAKI
Format Patent
LanguageEnglish
Published 28.10.2004
Edition7
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
MULTIPLEX COMMUNICATION
PICTORIAL COMMUNICATION, e.g. TELEVISION
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Summary:PROBLEM TO BE SOLVED: To solve the problem of a conventional two-way digital CATV system that needs a cost of QPSK modulators for a head end system and QPSK demodulation circuits for receivers because all the receivers of the system have always to receive the same downward control signal in order to recognize a timing of an up signal. SOLUTION: The up signal control system inserts the upward control signal having conventionally been transmitted through an exclusive control channel to a digital signal selected and received by a CATV terminal in order to receive a video image so as to eliminate the need for the exclusive control channel. COPYRIGHT: (C)2005,JPO&NCIPI
Bibliography:Application Number: JP20030097883