公开(公告)号：DE60011051D1

公开(公告)日：2004-07-01

申请号：DE60011051

申请日：2000-02-14

Applicant: QUALCOMM INC

Inventor： DEJACO P

IPC: G10L19/12 ,  G10L19/14 ,  H03M7/30 ,  H03M7/36 ,  H04B14/04

Abstract: A method and apparatus for CELP-based to CELP-based vocoder packet translation. The apparatus includes a formant parameter translator and an excitation parameter translator. The formant parameter translator includes a model order converter and a time base converter. The method includes the steps of translating the formant filter coefficients of the input packet from the input CELP format to the output CELP format and translating the pitch and codebook parameters of the input speech packet from the input CELP format to the output CELP format. The step of translating the formant filter coefficients includes the steps of converting the model order of the formant filter coefficients from the model order of the input CELP format to the model order of the output CELP format and converting the time base of the resulting coefficients from the input CELP format time base to the output CELP format time base.

公开(公告)号：DE69620585T2

公开(公告)日：2002-11-28

申请号：DE69620585

申请日：1996-01-25

Applicant: QUALCOMM INC

Inventor： WEAVER A ,  LAM KATHERINE ,  JACOBS E ,  GARDNER R ,  DEJACO P ,  SIH C

IPC: G10L11/02 ,  G10L19/00 ,  G10L19/14 ,  H04B7/26 ,  H04B14/04 ,  H04Q11/04 ,  H04W88/18 ,  H04Q7/24

Abstract: When one vocoding system is coupled to another vocoding system, a tandem arrangement results. The tandem configuration results in voice quality degradation as speech is encoded and decoded, then encoded and decoded again. One reason for the degradation is that postfiltering performed at the output of the speech decoding process introduces distortions in the spectral content of the reconstructed speech as compared to the original speech. The present invention prevents the degradation due to the use of postfilters by modifying the postfiltering within the vocoders where a tandem configuration exists. A detection code is embedded within the data signal to indicate the existence of a tandem configuration. If the detection code is received at a vocoder, modified vocoding is established within the vocoders to prevent the degradation due to the postfiltering.

公开(公告)号：DE69620585D1

公开(公告)日：2002-05-16

申请号：DE69620585

申请日：1996-01-25

Applicant: QUALCOMM INC

Inventor： WEAVER A ,  LAM KATHERINE ,  JACOBS E ,  GARDNER R ,  DEJACO P ,  SIH C

IPC: G10L11/02 ,  G10L19/00 ,  G10L19/14 ,  H04B7/26 ,  H04B14/04 ,  H04Q11/04 ,  H04W88/18 ,  H04Q7/24

Abstract: When one vocoding system is coupled to another vocoding system, a tandem arrangement results. The tandem configuration results in voice quality degradation as speech is encoded and decoded, then encoded and decoded again. One reason for the degradation is that postfiltering performed at the output of the speech decoding process introduces distortions in the spectral content of the reconstructed speech as compared to the original speech. The present invention prevents the degradation due to the use of postfilters by modifying the postfiltering within the vocoders where a tandem configuration exists. A detection code is embedded within the data signal to indicate the existence of a tandem configuration. If the detection code is received at a vocoder, modified vocoding is established within the vocoders to prevent the degradation due to the postfiltering.