| 摘要 |
PROBLEM TO BE SOLVED: To efficiently utilize frequency resources of transmission frequencies used in a cable television station, and to increase an information quantity assigned to a broadcast content in the cable television station. SOLUTION: A cable television multiplexing device sends the broadcast content via a CATV network 21 together with additional information 7, 13 exemplifying at least one of EPG information, limited reception information, and channel selecting information. In this device, the additional information is separated from the broadcast wave of the broadcast content and subjected to spreading spectrum processing, and the additional information subjected to the spread spectrum processing 15 and the broadcast wave are frequency-multiplexed 6, and sent out to the CATV network. Also, amplifiers 12, 18 are provided on a front stream side for applying a frequency multiplexing to the additional information subjected to spreading spectrum processing, C/N in an output of frequency multiplexing in which the additional information in a sent signal subjected to frequency multiplexing processing becomes a noise component is monitored 20, and gains of the amplifiers are controlled so that the C/N comes within a predetermined range. COPYRIGHT: (C)2006,JPO&NCIPI
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