Apparatus and method for coding signal in a communication system
View Patent ↗Provided is an apparatus and method for encoding a voice and audio signal by expanding a modified discrete cosine transform (MDCT) based CODEC to a wideband and a super-wideband in a communication system. The apparatus for encoding a signal in a communication system, includes a converter configured to convert a time domain signal corresponding to a service to be provided to users to a frequency domain signal, a quantization and normalization unit configured to calculate and quantize gain of each subband in the converted frequency domain signal and normalize a frequency coefficient of the each subband, a search unit configured to search patch information of each subband in the converted frequency domain signal using the normalized frequency coefficient, and a packetizer configured to packetize the quantized gain and the searched patch information and encode gain information of each subband in the frequency domain signal.
1. An apparatus for encoding a signal in a communication system, comprising:
a converter configured to convert a time domain signal to a frequency domain signal wherein the time domain signal is a signal corresponding to a service to be provided to users;
a quantization and normalization unit configured to calculate and quantize gain of each subband in the converted frequency domain signal and normalize a frequency coefficient of the each subband;
a search unit configured to search patch information of each subband in the converted frequency domain signal using the normalized frequency coefficient; and
a packetizer configured to packetize the quantized gain and the searched patch information and encode gain information of each subband in the frequency domain signal.
2. The apparatus of claim 1 , wherein the converter converts the time domain signal to a frequency domain highband signal and a frequency domain lowband signal based on a modified discrete cosine transform (MDCT) scheme.
3. The apparatus of claim 2 , wherein the quantization and normalization unit normalizes the MDCT coefficient of each subband with the frequency coefficient.
4. The apparatus of claim 1 , wherein the quantization and normalization unit calculates a gain of the each subband using a frequency coefficient of the each subband and calculates a quantized gain by quantizing the calculated gain with a comparative gain rate between subbands.
5. The apparatus of claim 4 , wherein the quantization and normalization unit normalizes a frequency coefficient of each subband in the converted frequency domain signal using the quantized gain.
6. The apparatus of claim 1 , wherein the search unit calculates a patch index of each subband based on a minimum mean square error (MMSE) using the normalized frequency coefficient.
7. The apparatus of claim 6 , wherein the packetizer encodes the gain information at a bandwidth extension (BWE) layer by packetizing the quantized gain and the patch index.
8. The apparatus of claim 7 , wherein the encoded gain information is shared in all wideband and super-wideband for the frequency domain signal when compensating a gain.
9. The apparatus of claim 1 , wherein the time domain signal is encoded through a modified discrete cosine transform (MDCT) based voice and audio CODEC extended to a wideband and super wideband.
10. A method for encoding a signal in a communication system, comprising:
converting a time domain voice and audio signal to a frequency domain lowband voice and audio signal and a frequency domain highband voice and audio signal, wherein the time domain voice and audio signal is a signal corresponding to a service to be provided to users;
calculating a gain of each subband in the lowband voice and audio signal and the highband voice and audio signal;
calculating a quantized gain by quantizing the calculated gain;
calculating a normalized frequency coefficient by normalizing a frequency coefficient of the each subband through the quantized gain;
calculating patch information of each subband in the lowband voice and audio signal and the highband voice and audio signal using the normalized frequency coefficient; and
encoding gain information of each subband in the lowband voice and audio signal and the highband voice and audio signal by packetizing the quantized gain and the patch information.
11. The method of claim 10 , wherein in said converting,
the time domain voice and audio signal is converted to the frame domain lowband voice and audio signal and the frame domain highband voice and audio signal based on a modified discrete cosine transform (MDCT).
12. The method of claim 11 , wherein the frequency coefficient is a modified discrete cosine transform coefficient of the lowband voice and audio signal and the highband voice and audio signal.
13. The method of claim 10 , wherein in said calculating a quantized gain,
the quantized gain is calculated by quantizing the calculated gain with a comparative gain ration between subbands in the lowband voice and audio signal and the highband voice and audio signal.
14. The method of claim 10 , wherein in said calculating patch information, the patch information is calculated in the each subband based on a minimum mean square error (MMSE) using the normalized frequency coefficient.
15. The method of claim 10 , wherein in said encoding,
the gain information is encoded in a bandwidth extension (BWE) layer to be shared in all wideband and super wideband for the lowband voice and audio signal and the highband voice and audio signal when compensating a gain.
16. The method of claim 10 , wherein the time domain voice and audio signal is encoded through a modified discrete cosine transform (MDCT) based voice and audio CODEC extended to a wideband and a super-wideband.