System and method 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 using variable-rate information-embedding. The system includes a data rate selector that selects, for example, a first host signal from two or more television signals based on an association between the first host signal and a first user end. A first data signal is embedded into the first host signal at a first data rate, thereby generating a first composite signal that comprises a digitally watermarked version of the first host signal. The first data signal may be associated with the firs user end. The first data rate is selected by a data rate selector that may, but need not, be included in a modulator coupled to the head end of the cable network. Alternatively, or in addition, data rate selectors may be included in demodulators at the users ends. The data rate selectors may select a rate for embedding data to the be transmitted to a particular user end based on the signal-to-noise ratio over the cable network to that user end. Determination of this ratio may be based, at least in part, on the distance from the head end of the cable network to that user end. Also, the data rate may be based on a user-defined acceptable level of distortion. The system may selected host signals based on signal-to-noise ratios over the cable network to the respective user ends.