Synchronization system and method for transmission and reception in audible frequency range-based sound communication, and apparatus applied thereto
First Claim
1. A receiving apparatus for acoustic data communication in audible frequency range, the apparatus comprising:
- a transforming unit configured to receive an audio signal, the audio signal being formed by inserting synchronization data into a frequency-domain signal transformed based on a first-type transform and being inverse-transformed, based on the first-type transform, into a time-domain signal, and to transform the audio signal into a frequency-domain signal based on a second-type transform;
a normalizing unit configured to normalize a size of coefficient of the frequency-domain signal transformed based on the second-type transform to a predetermined size;
an inner product calculating unit configured to calculate an inner product of the normalized signal and a pre-generated synchronization signal;
an inverse-transforming unit configured to inverse-transform, based on the second-type transform, a result of the inner product;
a correlation unit configured to generate a correlation value by overlapping the inverse-transformed signal with a previous inversed transformed signal in a predetermined interval; and
a synchronization point detecting unit configured to determine a point of the synchronization data based on a point of a peak in the correlation value.
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Abstract
Provided is a synchronization system and method for acoustic communication in audible frequency range, and an apparatus applied thereto. The synchronization system for acoustic communication in audible frequency range is configured to prevent deterioration of a synchronization performance and to reduce an amount of calculation by calculating a correlation based on a few samples as opposed to calculating a correlation for each sample when a receiver of the acoustic communication performs synchronization while the acoustic communication is performed in the audible frequency range through modification of an audio signal or adding of a predetermined signal to an audio signal.
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Citations
8 Claims
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1. A receiving apparatus for acoustic data communication in audible frequency range, the apparatus comprising:
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a transforming unit configured to receive an audio signal, the audio signal being formed by inserting synchronization data into a frequency-domain signal transformed based on a first-type transform and being inverse-transformed, based on the first-type transform, into a time-domain signal, and to transform the audio signal into a frequency-domain signal based on a second-type transform; a normalizing unit configured to normalize a size of coefficient of the frequency-domain signal transformed based on the second-type transform to a predetermined size; an inner product calculating unit configured to calculate an inner product of the normalized signal and a pre-generated synchronization signal; an inverse-transforming unit configured to inverse-transform, based on the second-type transform, a result of the inner product; a correlation unit configured to generate a correlation value by overlapping the inverse-transformed signal with a previous inversed transformed signal in a predetermined interval; and a synchronization point detecting unit configured to determine a point of the synchronization data based on a point of a peak in the correlation value. - View Dependent Claims (2, 3, 4, 5)
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6. A synchronization method for acoustic data communication in audible frequency range, the method comprising:
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receiving an audio signal, the audio signal being formed by inserting synchronization data into a frequency-domain signal transformed based on a first-type transform and being inverse-transformed, based on the first-type transform, into a time-domain signal, and transforming the audio signal into a frequency-domain signal based on a second-type transform; normalizing, to a predetermined size, a size of coefficient of the frequency-domain signal transformed based on the second-type transform; calculating an inner product of the normalized signal and a pre-generated synchronization signal; inverse-transforming, based on the second-type transform, a result of the inner product; generating a correlation value by overlapping the inverse-transformed signal with a previous inversed transformed signal in a predetermined interval; and determining a point of the synchronization data based on a peak value in the correlation value. - View Dependent Claims (7, 8)
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Specification