SYSTEM FOR VARIABLE-RATE MODULATION AND DEMODULATION OF DATA USING INFORMATION EMBEDDING IN TELEVISION SIGNALS

摘要

A system is described for providing data signals to user ends of a cable network (199) using variable-rate information-embedding. The system includes a DR selector (225) that selects (210), a host signal from two or more TV signals based on an association between the host signal and the user. A first data signal is embedded (220) into the host signal at a first data rate (DR), thereby generating a composite signal that comprises a digitally watermarked version of the host signal. The DR selectors may be included in modulators (110). Additionally DR selectors may be included in demodulators at the users ends. The DR selectors may select a DR for embedding data to be transmitted to a particular user based on the S/N ratio over the network. Determination of this ratio may be partially based on the distance from the user to the headend. Also the DR may be based on a user-defined acceptable level of distortion.