SCRAMBLING AND DESCRAMBLING OF TELEVISION SIGNALS FOR SUBSCRIPTION TV.

摘要

Subscription TV premium programming may be encoded with tagging information as by transmitting a tagging pulse during at least one horizontal line interval of each picture field in addition to pulses which are used to time the restoration of horizontal sync in the descrambler of a sync suppressed scrambling system. The additional tagging pulses provide information necessary to enable or disable the descrambler, and thereby provide high level encoding with minimum hardware complexity.