Method for transporting low-bit rate information

摘要

A method is presented that uses steganographic codeword(s) carried in a speech payload in such a way that (i) the steganographic codeword(s) survive compression and/or transcoding as the payload travels from a transmitter to a receiver across at least one diverse network, and (ii) the embedded steganographic codeword(s) do not degrade the perceived voice quality of the received signal below an acceptable level. The steganographic codewords are combined with a speech payload by summing the amplitude of a steganographic codeword to the amplitude of the speech payload at a relatively low steganographic-to-speech bit rate. Advantageously, the illustrative embodiment of the present invention enables (i) steganographic codewords to be decoded by a compliant receiver and applied accordingly, and (ii) legacy or non-compliant receivers to play the received speech payload with resultant voice quality that is acceptable to listeners even though the steganographic codeword(s) remain in the received speech payload.

主权项

1. A method comprising:
directly summing by a transmitter the amplitude of a plurality of codewords to the amplitude of a speech signal to generate a steganographic speech signal; encoding the steganographic speech signal in accordance with a voice encoding protocol to generate an encoded speech signal; decoding the encoded speech signal in accordance with the voice encoding protocol to generate an estimate of the steganographic speech signal; detecting by a receiver a framing of orthogonal codewords in the estimate of the steganographic speech signal; correlating each frame of the estimate of the steganographic speech signal with an orthogonal codeword known to the receiver, to produce a correlation; determining a matching codeword based upon the correlation; and generating an estimate of the orthogonal codeword.