US 4,805,014 AGranted

Signal transmission system for a CATV system

AssigneeSony Corporation

InventorsHiroshi Sahara, Yoshimi Watanabe

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Abstract

A CATV (cable television) signal transmitting system for use with a broadcast satellite system includes a receiving stage for receiving a broadcast satellite station signal consisting of base-band video signals and a sub-channel digital audio signals PSK (phase shift keying)-modulated on sub-carriers, demodulators for deriving the video signals and digital audio signals, first modulators for modulating the main carriers of a plurality of CATV channels by the video signals, a second modulator for modulating the main carrier of a different channel by the digital audio signals in time-division manner. The mixed output signal from the first and second modulators is transmitted through a CATV transmission line. A CATV signal receiving system is also provided to produce video signals and digital audio signals which are converted into a plurality of channels of analog audio signals.

Claims6

Dependent claims

A CATV signal transmitting system comprising:

(a) receiving means for receiving a plurality of broadcast satellite channel signals, each channel signal consisting of a base-band video signal modulated on a carrier and a subchannel digitally coded audio signal modulated on a sub-carrier;
(b) means connected to said receiving means for demodulating a plurality of base-band video signals and a plurality of respective sub-channel digitally coded audio signals from said received plurality of channel signals;
(c) first modulating means for modulating said plurality of base-band video signals for transmission in respective CATV channels;
(d) interface means receiving the demodulated sub-channel digitally coded audio signals and arranging said sub-channel digitally coded audio signals so as to be time-division multiplexed into a multiplexed, digitally coded audio signal consisting of a plurality of frames, each frame including at least a portion of each of said demodulated digitally coded audio signals, and an error check code signal;
(e) second modulating means for modulating said time-division multiplexed digitally coded audio signal from said interface means for transmission in a CATV channel other than said respective CATV channels;
and
(f) means for combining the output signals of said first and second modulating means and for transmitting the combined signals through a CATV transmission line;
whereby said audio signals as transmitted through said CATV transmission line have a bandwidth and dynamic range that undergo substantially no deterioration.

5 more elements

A CATV signal transmitting system comprising:

(a) receiving means for receiving a plurality of broadcast satellite channel signals, each channel signal consisting of a base-band video signal modulated on a carrier and a sub-channel digital PCM audio signal modulated on a sub-carrier;
(b) means connected to said receiving means for demodulating a plurality of base-band video signals and a respective plurality of corresponding sub-channel digital PCM audio signals from said received plurality of channel signals;
(c) first means for modulating a plurality of main carriers of a larger plurality of predetermined CATV channels by respective ones of the plurality of demodulated video signals;
(d) interface means having the plurality of demodulated sub-channel digital PCM audio signals fed thereto and arranging the demodulated sub-channel digital audio PCM signals into a time-division multiplexed output digital signal formed of a plurality of frames, each frame including at least a portion of each of said digital PCM audio signals, and an error code signal;
(e) second means for modulating a main carrier of one of said predetermined CATV channels other than the ones thereof modulated by said first means for modulating by said time-division multiplexed output digital signal from said interface means;
and
(f) means for combining output signals of said first and second means for modulating and for transmitting the combined signal through a CATV transmission line;
whereby said audio signals as transmitted through said CATV transmission line have a bandwidth and dynamic range that undergo substantially no deterioration.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/096,773Filed 14 Sep 1987 · continuation
Priority: JP 58-2087417 Nov 1983
Granted: 14 Feb 1989
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H04H 40/90
Specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95: specially adapted for satellite broadcast receiving
H04N 7/06
Television systems: systems for the simultaneous transmission of one television signal, i.e. both picture and sound, by more than one carrier
H04N 7/10
Television systems: adaptations for transmission by electrical cable
H04H
Broadcast communication