1. Field of the Invention
Embodiments relate to an apparatus and method for hiding data in an audio signal and extracting the data from the audio signal, and more particularly, to an apparatus and method for hiding data in an audio signal and extracting the data from the audio signal based on a pilot code sequence.
2. Description of the Related Art
An audio watermark technology includes a technology of carrying required additional information in an audio signal by adding arbitrary distortion or a arbitrary signal and of extracting the additional information. The additional information carried on the audio signal may be used to guarantee a quality of the audio signal at a minimum loss and to discriminate a copyright of the original audio signal.
Recently, due to a wide use of portable smart terminal equipment, the audio watermark technology is showing a possibility to be used as a scheme of transmitting additional information utilized in a portable terminal in addition to copyright discrimination. In addition to existing constraints, additional information may need to be extracted robustly against acoustic channel distortion until the audio signal is spread in the air and received to a microphone. Also, to perform an additional service desired by a user, a high quantity of data associated with transmitted additional information may be required. For example, the additional information may include, for example, channel information, time information or uniform resource locator (URL) information. A portable terminal may extract text information from a received signal only when tens of bytes of text information is transmitted within a set period of time.
However, in most cases, a large number of bit errors may occur in data associated with extracted additional information due to reverberation or noise occurring in an acoustic channel, in comparison to the original data.