SPEECH CODER AND METHOD, SPEECH DECODER AND METHOD, SPEECH BAND SPREADING APPARATUS AND METHOD

Title:

SPEECH CODER AND METHOD, SPEECH DECODER AND METHOD, SPEECH BAND SPREADING APPARATUS AND METHOD

Document Type and Number:

Japanese Patent JP2010020251

Kind Code:

A

Abstract:

To improve the subjective quality of a decryption signal by precisely adjusting the microstructure of a high-frequency spectrum dependent on frequency in speech coding and speech decoding in a band spreading technique.

The speech decoder for decoding a speech signal including a frequency component corresponding to both low-frequency spectrum and high-frequency spectrum from a bit stream including encoded information of the low-frequency spectrum of speech signal and auxiliary information related to the nature of the high-frequency spectrum includes: a means for separating the bit stream into encoded information of the low-frequency spectrum of the speech signal and the auxiliary information related to the nature of the high-frequency spectrum; a means for decoding the low-frequency spectrum from the encoded information of the low-frequency spectrum of the speech signal; a means for obtaining a first high-frequency spectrum by copying part or the whole of the low-frequency spectrum obtained by decoding to the high-frequency region; a spectrum shape adjusting means for obtaining a second high-frequency spectrum by adjusting the shape of the first high-frequency spectrum utilizing the auxiliary information; and a means for decoding the speech signal utilizing the low-frequency spectrum and the second high-frequency spectrum.

Inventors:

TSUJINO KOSUKE
KIKUIRI KEI

Application Number:

JP2008183113A

Publication Date:

January 28, 2010

Filing Date:

July 14, 2008

Export Citation:

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Assignee:

NTT DOCOMO INC

International Classes:

G10L19/00; G10L19/02; G10L21/007; G10L21/02; G10L21/0388; H03M7/30

Domestic Patent References:

JP2007187905A	2007-07-26
JP2006293400A	2006-10-26
JP2005510772A	2005-04-21
JP2003216190A	2003-07-30
JP2007187905A	2007-07-26

Foreign References:

WO2005104094A1	2005-11-03
WO2006132054A1	2006-12-14
WO2006132054A1	2006-12-14
WO2005104094A1	2005-11-03

Attorney, Agent or Firm:

Yoshiki Hasegawa
Shiro Terasaki
Takashi Okiyama
Kenji Fukaishi

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