Sub-band adaptive differential pulse code modulation/encoding apparatus, sub-band adaptive differential pulse code modulation/encoding method, wireless transmission system, sub-band adaptive differential pulse code modulation/decoding apparatus, sub-band adaptive differential pulse code modulation/decoding method, and wirel

A sub-band adaptive differential pulse code modulation/encoding apparatus comprising:

• a microphone for inputting an audio and converting the inputted audio into an audio signal;
• discrete audio signal obtaining means for sampling said converted audio signal at predetermined intervals, so as to obtain a discrete audio signal;
• sub-band audio signal obtaining means having a predetermined asymmetric impulse response for receiving an audio signal and band division the received audio signal into a predetermined number of sub-bands, so as to obtain a plurality of band-divided sub-band discrete audio signals;
• a plurality of down-samplers for down-sampling said band-divided sub-band discrete audio signals for a predetermined sampling frequencies of said plural sub-bands to thin down said divided sub-band discrete audio signals
• a plurality of quantization means for vector-quantizing said down-sampled sub-band discrete audio signals with the predetermined of sub-bands;
• and
• encoding means for performing adaptive differential pulse code modulation/encoding the quantized sub-band audio signals.

A sub-band adaptive differential pulse code modulation/encoding method comprising:

• a preparing process of preparing a plurality of sub-band audio signal obtaining means having a predetermined asymmetric impulse response for receiving an audio signal and band-dividing the received audio signal into a predetermined number of sub-bands, so as to obtain a plurality of band-divided sub-band audio signals, a plurality of quantization means for quantizing said band-divided sub-band audio signals with the predetermined number of sub-bands, and encoding means for performing adaptive differential pulse code modulation/encoding said quantized sub-band audio signals;
• a plurality of sub-bands audio signal obtaining processes of making said band division filter band-divide said received audio signal into said predetermined number of sub-bands, so as to obtain said plural band-divided sub-band audio signals, respectively;
• a plurality of quantizing processes of making said plural quantization means respectively quantize said band-divided sub-band audio signals with the predetermined number of sub-bands;
• and
• an encoding process of performing adaptive differential pulse code modulation/encoding said quantized plural sub-band audio signals by said plurality of quantization means.

A wireless transmission system comprising:

• sub-band audio signal obtaining means having a predetermined asymmetric impulse response for receiving an audio signal and band-dividing the received audio signal into a predetermined number of sub-bands, so as to obtain a plurality of band-divided sub-band audio signals;
• a plurality of quantization means for quantizing said band-divided sub-band audio signals with the predetermined number of sub-bands;
• and
• encoding means for performing adaptive differential pulse code modulation/encoding the quantized sub-band audio signals.

A sub-band adaptive differential pulse code modulation/decoding apparatus comprising:

• sub-band separating means for receiving a coded audio signal encoded from a plurality of sub-band audio signals including a plurality of sub-bands, and separating said plural sub-band coded audio signals from said coded audio signal;
• a plurality of de-quantization means for de-quantizing said plural sub-band coded audio signals with a predetermined number of sub-bands;
• and
• a plurality of band synthesizing means for band-synthesizing an audio signal from said de-quantized plural sub-band audio signals.

A sub-band adaptive differential pulse code modulation/decoding apparatus comprising:

• a sub-band separating means for receiving a plurality of sub-band audio signals, for a plurality of sub-bands, encoded from a plurality of audio signals of said plural sub-bands, and separating a plurality of index numbers respectively corresponding to a plurality of code vectors which is used to vector-quantize said plural sub-band coded audio signals to obtain said plural sub-band audio signals;
• a plurality of de-quantization means for vector-de-quantizing to obtain said plural sub-band audio signals on the basis of the separated index numbers;
• an up-sampler for up-sampling for up-sampling said predetermined plural sub-band audio signals so as to interpolate the thinned down sampled values into the plural sub-band audio signals down-sampled for thinning down;
• and
• a band synthesizing means for band-synthesizing said audio signal from said sub-band audio components having said plural sub-band audio signals.

A sub-band adaptive differential pulse code modulation/decoding method comprising:

• a preparing process of preparing sub-band separating means for receiving a coded audio signal encoded from a plurality of sub-band audio signals including a plurality of sub-bands, and separating said plural sub-band coded audio signals from said coded audio signal,
• a plurality of de-quantization means for de-quantizing said plural sub-band coded audio signals with a predetermined number of sub-bands, and
• band synthesizing means for band-synthesizing an audio signal from said de-quantized plural sub-band audio signals;
• a sub-band separating process of receiving a coded audio signal encoded from a plurality of sub-band audio signals including a plurality of sub-bands, and making said sub-band separating means separate said plural sub-band coded audio signals from said coded audio signal,
• a plurality of de-quantizing processes of making said plural de-quantization means respectively de-quantize said plural sub-band coded audio signals with the predetermined number of sub-bands;
• and
• band synthesizing process of making said synthesizing means band-synthesize said audio signals from said de-quantized plural sub-band audio signals.

A wireless receiving system comprising:

• sub-band separating means for receiving a coded audio signal encoded from a plurality of sub-band audio signals including a plurality of sub-bands, and separating said plural sub-band coded audio signals from said coded audio signal;
• a plurality of de-quantization means for de-quantizing said plural sub-band coded audio signals with a predetermined number of sub-bands;
• and
• a plurality of band synthesizing means for band-synthesizing an audio signal from said de-quantized plural sub-band audio signals.