公开(公告)号：US5261027A

公开(公告)日：1993-11-09

申请号：US997667

申请日：1992-12-28

申请人： Tomohiko Taniguchi ,  Yoshinori Tanaka ,  Yasuji Ohta ,  Fumio Amano ,  Shigeyuki Unagami ,  Akira Sasama

发明人： Tomohiko Taniguchi ,  Yoshinori Tanaka ,  Yasuji Ohta ,  Fumio Amano ,  Shigeyuki Unagami ,  Akira Sasama

IPC分类号： G10L11/06 ,  G10L19/00 ,  G10L19/12 ,  G10L9/00

CPC分类号： G10L19/12 ,  G10L25/93

摘要： A code excited linear prediction (CELP) type speech signal coding system is provided, a code vector obtained by applying linear prediction to a vector of a residual speech signal of white noise is stored in a code book. A pitch prediction vector obtained by applying linear prediction to a residual signal of a preceding frame is given a delay corresponding to a pitch frequency and added to the code vector. Use is made of an impulse vector obtained by applying linear prediction to a residual signal vector of impulses having a predetermined relationship with the vectors of the white noise code book. Variable gains are given to at least the above code vector and impulse vector, a reproduced signal is produced, and this reproduced signal is used for identification of the input speech signal. Thus, a pulse series corresponding to the sound source of voiced speech sounds is created.

摘要翻译： 提供码激励线性预测（CELP）型语音信号编码系统，通过对白噪声的残留语音信号的向量应用线性预测而获得的码矢量被存储在码本中。 通过对前一帧的残差信号应用线性预测而获得的音调预测矢量被给予对应于音调频率的延迟并被加到码矢量。 使用通过对与白噪声码本的矢量具有预定关系的脉冲的残差信号矢量应用线性预测而获得的脉冲矢量。 至少对上述代码矢量和脉冲矢量赋予可变增益，产生再生信号，该再现信号用于识别输入语音信号。 因此，产生对应于有声语音的声源的脉冲序列。

公开(公告)号：US5231692A

公开(公告)日：1993-07-27

申请号：US593756

申请日：1990-10-05

申请人： Yoshinori Tanaka ,  Tomohiko Taniguchi ,  Akira Sasama ,  Yasuji Ohta ,  Fumio Amano ,  Shigeyuki Unagami

发明人： Yoshinori Tanaka ,  Tomohiko Taniguchi ,  Akira Sasama ,  Yasuji Ohta ,  Fumio Amano ,  Shigeyuki Unagami

IPC分类号： G10L25/90 ,  H03H17/00 ,  H03H17/02

CPC分类号： G10L25/90

摘要： Pitch periods for a long term predictor included in a speech codec are searched in two searching stages. In the first searching stage, probable pitch periods are searched skipping a constant number of pitch periods, and in the second searching stage, pitch periods including the pitch period determined in the first searching stage and pitch periods neighboring the pitch period on both sides are searched.

公开(公告)号：US5224167A

公开(公告)日：1993-06-29

申请号：US580669

申请日：1990-09-11

申请人： Tomohiko Taniguchi ,  Yoshinori Tanaka ,  Akira Sasama ,  Yasuji Ohta ,  Fumio Amano ,  Shigeyuki Unagami

发明人： Tomohiko Taniguchi ,  Yoshinori Tanaka ,  Akira Sasama ,  Yasuji Ohta ,  Fumio Amano ,  Shigeyuki Unagami

IPC分类号： H03M13/00 ,  G10L19/14 ,  H04L1/20

CPC分类号： G10L19/18 ,  H04L1/20

摘要： A speech coding apparatus coupled to a transmission channel includes m (m is an integer greater than 1) coders, m decoders and m or (m-1) error correcting coders. The apparatus also includes an evaluation unit which evaluates a quality of each of reproduced speech signals from the input speech signal and the reproduced speech signals and which outputs an evaluated quality of each of the reproduced speech signals. The quality of each of the reproduced speech signals is evaluated in a state having no transmission error. A decision unit identifies one of the m coders which provides the reproduced speech signal having a smallest distortion on the basis of the evaluated quality of each of the reproduced speech signals, a current error rate of the transmission channel and error correcting abilities of the error correcting coders, and generates a coder identification number representative of a selected one of the m coders. An output part outputs a multiplexed transmission signal including the coded speech signal generated by the one of the m coders identified by the decision unit and the error correcting code generated by a corresponding one of the m error correcting coders.