Data embedding device, data embedding method, data extraction device, and data extraction method

A data extraction device, comprising:

• a processor configured to:
• synchronize an acoustic signal in accordance with a frame unit used when arbitrary transmission data was embedded in the acoustic signal by detecting synchronization points in the acoustic signal;
• remove a low frequency component from the synchronized acoustic signal to generate a second low-frequency-removed acoustic signal;
• divide the second low-frequency-removed acoustic signal into frames on the basis of the synchronization points;
• and
• extract the transmission data from the second low-frequency-removed acoustic signal based on a correlation value obtained by multiplying each of the frames of the second low-frequency-removed acoustic signal by a predetermined spread code sequence, so as to identify a first bit value if the correlation value is plus at a synchronization point of the frame, and to identify a second bit value if the correlation value is minus at a synchronization point of the frame, wherein
• the synchronizing includes calculating second correlation values between the acoustic signal and the spread code sequence by iteratively shifting the acoustic signal by several samples and detecting a point with a highest second correlation value as a synchronization point of the frame.

A data extraction method performed by a data extraction device, the method comprising:

• removing a low frequency component from an acoustic signal in which arbitrary transmission data is embedded to generate a first low-frequency-removed acoustic signal;
• synchronizing the first low-frequency-removed acoustic signal in accordance with a frame unit used when said transmission data was embedded in the acoustic signal by detecting synchronization points in the first low-frequency-removed acoustic signal;
• dividing the first low-frequency-removed acoustic signal into frames on the basis of the synchronization points;
• and
• extracting the transmission data from the synchronized first low-frequency-removed acoustic signal based on a correlation value obtained by multiplying each of the frames of the synchronized first low-frequency-removed acoustic signal by a predetermined spread code sequence so as to identify a first bit value if the correlation value is plus at a synchronization point of the frame, and to identify a second bit value, if the correlation value is minus at a synchronization point of the frame, wherein
• the synchronizing includes calculating second correlation values between the first low-frequency-removed acoustic signal and the spread code sequence by iteratively shifting the first low-frequency-removed acoustic signal by several samples and detecting a point with a highest second correlation value as a synchronization point of the frame.

A data extraction method performed by a data extraction device, the method comprising:

• synchronizing an acoustic signal in accordance with a frame unit used when arbitrary transmission data was embedded in the acoustic signal by detecting synchronization points in the acoustic signal;
• removing a low frequency component from the synchronized acoustic signal to generate a second low-frequency-removed acoustic signal;
• dividing the second low-frequency-removed acoustic signal into frames on the basis of the synchronization points;
• and
• extracting the transmission data from the second low-frequency-removed acoustic signal based on a correlation value obtained by multiplying each of the frames of the second low-frequency-removed acoustic signal by a predetermined spread code sequence so as to identify a first bit value if the correlation value is plus at a synchronization point of the frame, and to identify a second bit value if the correlation value is minus at a synchronization point of the frame, wherein
• the synchronizing includes calculating second correlation values between the acoustic signal and the spread code sequence by iteratively shifting the acoustic signal by several samples and detecting a point with a highest second correlation value as a synchronization point of the frame.