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    2.
    发明专利
    未知

    公开(公告)号：DE3688980T2

    公开(公告)日：1994-04-21

    申请号：DE3688980

    申请日：1986-10-30

    Applicant: IBM

    Inventor： ROSSO MICHELE ,  GALAND CLAUDE

    IPC: G10L19/02 ,  G10L19/00 ,  H03M1/12 ,  H03M7/30 ,  H04B1/66 ,  H04B14/04

    Abstract: A process for multirate subband encoding voice signals. At least a portion of the original signal bandwidth is plit into p sub-bands the contents of which is to be coded using dynamic allocation of quantizing levels throughout the sub-bands. Let's assume the signal is to be coded for a set of coding rates R(1) Then the sub-band samples S(i,j) are quantized according to 1(i; R(K). And, finally the obtained quantized sub-band samples are embedded into a multirate frame.

    3.
    发明专利
    未知

    公开(公告)号：DE3871369D1

    公开(公告)日：1992-06-25

    申请号：DE3871369

    申请日：1988-03-08

    Applicant: IBM

    Inventor： BOTTAU FRANCOISE ,  GALAND CLAUDE ,  MENEZ JEAN ,  ROSSO MICHELE

    IPC: G10L19/06 ,  G10L19/12 ,  H03M7/30 ,  G10L9/14

    Abstract: The encoding process comprises the steps of filtering voice signal using a short-term predictive filter tuned by sets of partial correlation related coefficients derived from s(n) and deriving from them a short-term residual r(n). A long-term residual e(n) is derived by subtracting a weighted and delayed synthesis short-term residual from the r(n). E(n) is split into consecutive blocks. Each block of the long term residual e(n) is code excited encoded into one TABLE address reference k and one gain G.

    4.
    发明专利
    未知

    公开(公告)号：DE3853161D1

    公开(公告)日：1995-03-30

    申请号：DE3853161

    申请日：1988-10-19

    Applicant: IBM

    Inventor： GALAND CLAUDE ,  MENEZ JEAN ,  ROSSO MICHELE

    IPC: H03M7/30 ,  G06T9/00 ,  G10L19/06 ,  G10L9/14

    Abstract: A signal vector quantizing coder (CELP) is provided with an adaptive codebook originally loaded with preselected codewords. The codebook is split into a fixed contents portion and a fixed length adaptive contents portion. During coding operations, the codewords dynamically selected for coding the coder input signal are shifted into the fixed length adaptive codebook section for codebook contents updating purposes.

    6.
    发明专利
    未知

    公开(公告)号：DE3883519T2

    公开(公告)日：1994-03-17

    申请号：DE3883519

    申请日：1988-03-08

    Applicant: IBM

    Inventor： BOTTAU FRANCOISE ,  GALAND CLAUDE ,  ROSSO MICHELE

    IPC: G10L19/06 ,  G10L19/12 ,  G10L9/14

    Abstract: The voice signal s(n) is filtered through a short-term predictive filter (13) tuned with PARCOR derived coefficients computed over a pre-emphasized s(n), said filter (13) providing a short-term residual r(n). Said r(n) signal is then processed through a first Code-Excited/Long-Term Predictive coder providing first couples of table address and gain data (k1, g1)'s. An error signal r min (n) is then derived by subtracting coded/decoded data from uncoded data. Then said error signal is processed through a second Code-Excited/ Long-Term Predictive coder providing second couples of data (k2, g2)'s. Full rate coding is achieved by multiplexing both couples (k1, g1)'s and (k2, g2)'s into a multi-rate frame; while switching to a lower rate is achieved through a mere delation of (g2, k2)'s from the full rate frame.

    8.
    发明专利
    未知

    公开(公告)号：DE69123579D1

    公开(公告)日：1997-01-23

    申请号：DE69123579

    申请日：1991-09-06

    Applicant: IBM

    Inventor： MENEZ JEAN ,  ROSSO MICHELE ,  SCOTTON PAOLO

    IPC: H03H15/00 ,  H03H17/00 ,  H03H21/00 ,  H04B3/23

    Abstract: The echo cancellation method includes starting with an arbitrary set of echo filter coefficients. The coefficients are first sequentially re-estimated using a fast converging method. These operations are repeated a predefined number of times, and then the coefficients estimation is switched to a low converging but more precise method. In addition, an adaptive threshold is being defined and readjusted and all filter coefficients lower than said threshold are being discarded. Finally, sampling time boundaries are adaptively defined based on non-discarded filter coefficients with reference to said threshold, and in such a way the final echo cancelation algorighm is adaptive to echo variations (backtracking algorithm).

    9.
    发明专利
    未知

    公开(公告)号：DE3853161T2

    公开(公告)日：1995-08-17

    申请号：DE3853161

    申请日：1988-10-19

    Applicant: IBM

    Inventor： GALAND CLAUDE ,  MENEZ JEAN ,  ROSSO MICHELE

    IPC: H03M7/30 ,  G06T9/00 ,  G10L19/06 ,  G10L9/14

    Abstract: A signal vector quantizing coder (CELP) is provided with an adaptive codebook originally loaded with preselected codewords. The codebook is split into a fixed contents portion and a fixed length adaptive contents portion. During coding operations, the codewords dynamically selected for coding the coder input signal are shifted into the fixed length adaptive codebook section for codebook contents updating purposes.

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