公开(公告)号：BR9607249A

公开(公告)日：1997-12-30

申请号：BR9607249

申请日：1996-09-04

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P

IPC: H04B1/10 ,  G10L21/02 ,  H04B15/00 ,  H04Q7/20

Abstract: A noise suppression system implemented in communication system provides an improved update decision during instances of sudden increase in background noise level. The noise suppression system, inter alia, generates an update by continually monitoring the deviation of spectral energy and forcing an update based on a predetermined threshold criterion. The spectral energy deviation is determined by utilizing an element which has the past values of the power spectral components exponentially weighted. The exponential weighting is a function of the current input energy, which means the higher the input signal energy the longer the exponential window. Conversely, the lower the signal energy the shorter the exponential window. The noise suppression system also inhibits a forced update during periods of continuous, non-stationary input signals (such as "music-on-hold").

公开(公告)号：FI972852A0

公开(公告)日：1997-07-03

申请号：FI972852

申请日：1997-07-03

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P

IPC: H04B1/10 ,  G10L21/02 ,  H04B15/00 ,  H04Q7/20 ,  H04B

Abstract: A noise suppression system implemented in communication system provides an improved update decision during instances of sudden increase in background noise level. The noise suppression system, inter alia, generates an update by continually monitoring the deviation of spectral energy and forcing an update based on a predetermined threshold criterion. The spectral energy deviation is determined by utilizing an element which has the past values of the power spectral components exponentially weighted. The exponential weighting is a function of the current input energy, which means the higher the input signal energy the longer the exponential window. Conversely, the lower the signal energy the shorter the exponential window. The noise suppression system also inhibits a forced update during periods of continuous, non-stationary input signals (such as "music-on-hold").

公开(公告)号：CA2203917A1

公开(公告)日：1997-05-14

申请号：CA2203917

申请日：1996-09-04

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P

IPC: H04B1/10 ,  G10L21/02 ,  H04B15/00 ,  H04Q7/20

Abstract: A noise suppression system implemented in communication system provides an improved update decision during instances of sudden increase in background noise level. The noise suppression system, inter alia, generates an update by continually monitoring the deviation of spectral energy and forcing an update based on a predetermined threshold criterion. The spectral energy deviation is determined by utilizing an element which has the past values of the power spectral components exponentially weighted. The exponential weighting is a function of the current input energy, which means the higher the input signal energy the longer the exponential window. Conversely, the lower the signal energy the shorter the exponential window. The noise suppression system also inhibits a forced update during periods of continuous, non-stationary input signals (such as "music-on-hold").

公开(公告)号：SE9701659D0

公开(公告)日：1997-05-02

申请号：SE9701659

申请日：1997-05-02

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P

IPC: G10L21/02 ,  H04B1/10 ,  H04B15/00 ,  H04Q7/20 ,  H04B

Abstract: A noise suppression system implemented in communication system provides an improved update decision during instances of sudden increase in background noise level. The noise suppression system, inter alia, generates an update by continually monitoring the deviation of spectral energy and forcing an update based on a predetermined threshold criterion. The spectral energy deviation is determined by utilizing an element which has the past values of the power spectral components exponentially weighted. The exponential weighting is a function of the current input energy, which means the higher the input signal energy the longer the exponential window. Conversely, the lower the signal energy the shorter the exponential window. The noise suppression system also inhibits a forced update during periods of continuous, non-stationary input signals (such as "music-on-hold").

公开(公告)号：FR2692089A1

公开(公告)日：1993-12-10

申请号：FR9304308

申请日：1993-04-13

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P ,  QUOC NGUYEN

IPC: H04B3/23 ,  H04B7/015 ,  H04B7/26

公开(公告)号：EP1697925A4

公开(公告)日：2009-07-08

申请号：EP04814785

申请日：2004-12-17

Applicant: MOTOROLA INC

Inventor： JASIUK MARK A ,  RAMABADRAN TENKASI V ,  MITTAL UDAR ,  ASHLEY JAMES P ,  MCLAUGHLIN MICHAEL J

IPC: G10L11/04 ,  G10L19/00 ,  G10L19/04 ,  G10L19/08 ,  G10L19/10 ,  G10L19/12

CPC classification number: G10L19/09

Abstract: A method (Fig. 9) and apparatus (500, 600) for prediction in a speech-coding system extends a 1st order long-term predictor (LTP) filter, using a sub-sample resolution delay, to a multi-tap LTP filter (504, 604). From another perspective, a conventional integer-sample resolution multi-tap LTP filter is extended to use sub-sample resolution delay. Such a multi-tap LTP filter offers a number of advantages over the prior-art. Particularly, defining the lag with sub-sample resolution makes it possible to explicitly model the delay values that have a fractional component, within the limits of resolution of the over-sampling factor used by the interpolation filter. The coefficients (ßi's) of the multi-tap LTP filter are thus largely freed from modeling the effect of delays that have a fractional component. Consequently their main function is to maximize the prediction gain of the LTP filter via modeling the degree of periodicity that is present and by imposing spectral shaping.

公开(公告)号：EP1922718A4

公开(公告)日：2008-09-03

申请号：EP06785795

申请日：2006-06-29

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P ,  MITTAL UDAR

IPC: G10L19/08 ,  G10L11/04

CPC classification number: G10L19/09 ,  G10L21/00 ,  G10L21/06

Abstract: In a speech encoder/decoder (200/300) a pitch delay contour endpoint modifier (208) is employed to shift the endpoints of a pitch delay interpolation curve up or down. Particularly, the endpoints of the pitch delay interpolation curve are shifted based on a variation and/or a standard deviation in pitch delay.

Abstract translation: 在语音编码器/解码器（200/300）中，采用音调延迟轮廓端点修改器（208）来将音高延迟插值曲线的端点向上或向下移位。 特别地，音调延迟插值曲线的端点基于音调延迟的变化和/或标准偏差而被移位。

公开(公告)号：EP1238479A4

公开(公告)日：2005-07-27

申请号：EP00980890

申请日：2000-11-30

Applicant: MOTOROLA INC

Inventor： RAMABADRAN TENKASI V ,  ASHLEY JAMES P

IPC: H04B3/06 ,  G10L21/02 ,  H04B15/00 ,  H04S1/00

CPC classification number: H04S1/007

Abstract: A method and apparatus for suppressing acoustic background noise in a communication system. An operating signal-to-noise ratio (SNR) level is reliably evaluated from channel energy (293) and background noise energy (294) values by a SNR level estimator (295). A minimum gain factor and a gain slope are adapted (290) depending on the operating SNR level. Using these adapted values and the channel SNR, the channel gain is selected (233). When the channel SNR is below a certain threshold, the channel is completely noise-like and the gain factor selected is minimum so that the channel is maximally attenuated. When the channel SNR is fairly high, the channel gain selected is 0 dB. For intermediate values of channel SNR, the gain factor selected lies between minimum and 0 dB.

公开(公告)号：EP1913590A4

公开(公告)日：2009-11-25

申请号：EP06786686

申请日：2006-07-07

Applicant: MOTOROLA INC

Inventor： MIRANDA-KNAPP CARLOS A ,  ASHLEY JAMES P

IPC: G10L21/00

CPC classification number: H04M1/573 ,  G10L21/00 ,  G10L2021/0135 ,  H04M1/6008 ,  H04M1/72544 ,  H04M15/06

公开(公告)号：EP1112625A4

公开(公告)日：2004-06-16

申请号：EP99943854

申请日：1999-08-24

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES P ,  PENG WEIMIN

IPC: H03M7/30 ,  H04B7/216 ,  G10L19/10

CPC classification number: G10L19/12 ,  H03M7/30

Abstract: To achieve high quality speech reconstruction at low bit rates, constraints on position combinations among two or more pulses (403) are implemented. By placing constraints on position combinations, certain combinations of pulses are prohibited which allows the most significant pulses to always be coded, thereby improving speech quality. After all valid combinations are considered, a list of pulse pairs (codebook) which can be indexed using a single, predetermined bit length codeword is produced. The codeword is transmitted to a destination where it is used by a decoder to reconstruct the original information signal.