Method for placing electronic watermarks in bandwidth-limited analog signals for marking or protecting digital data in microphone, involves adding signal at output of filter to analog signal to obtain analog signal protected with watermarks

摘要

The method involves producing short pulse depending on watermarks. The pulse is provided to an analog filter. A pulse response of the filter is subjected to small pulse cross-talks corresponding to a partial-response method. A signal at an output of the filter is added to the analog signal to obtain the analog signal protected with the watermarks. Energy of an analog watermark signal is regulated such that a certain signal-noise-ratio of a wanted signal to the watermark signal is obtained.