公开(公告)号：EP0979506B1

公开(公告)日：2005-06-29

申请号：EP98901181.2

申请日：1998-01-05

Applicant: MOTOROLA, INC.

Inventor： ASHLEY, James, P.

IPC: G10L19/14

CPC classification number: G10L19/18 ,  G10L25/78

公开(公告)号：EP1238479A1

公开(公告)日：2002-09-11

申请号：EP00980890.8

申请日：2000-11-30

Applicant: MOTOROLA, INC.

Inventor： RAMABADRAN, Tenkasi, V. ,  ASHLEY, James, P.

IPC: H04B15/00

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：EP1110339A1

公开(公告)日：2001-06-27

申请号：EP99942438.5

申请日：1999-08-24

Applicant: MOTOROLA, INC.

Inventor： ASHLEY, James, P. ,  PENG, Weimin

IPC: H04B11/00

CPC classification number: G10L19/09

Abstract: An open-loop delay contour estimator (204) generates delay information during coding of an information signal. The delay contour is adjusted according to an error minimization criterion on a subframe basis, which allows a more precise estimate of the true delay contour. A delay contour reconstruction block (211) uses the delay information in a decoder in reconstructing the information signal.

公开(公告)号：EP1092294A1

公开(公告)日：2001-04-18

申请号：EP99917565.6

申请日：1999-04-16

Applicant: MOTOROLA, INC.

Inventor： LOVE, Robert, T. ,  ASHLEY, James, P. ,  PROCTOR, Lee ,  BAROT, Anil ,  COHEN, Arnie

IPC: H04J3/16 ,  H04J3/22 ,  H04B7/216 ,  H04B15/00 ,  H04K1/00 ,  H04L27/30

CPC classification number: H04L1/0021 ,  H04L1/0009 ,  H04L1/0025 ,  H04W52/30

Abstract: Forward link communication capacity of a communication system, which is providing from a base station to a number of mobile stations a number of forward communication links (123) corresponding to the plurality of mobile stations, is controlled by receiving gain setting (102) associated with at least one of the forward communication links, comparing the gain setting with a gain threshold (123), and adjusting a first encoding rate of at least one of the forward communication links to a second encoding rate based on the comparing. A gain offset (310) attunes the gain threshold (123) to update the gain threshold (123) according to a latest condition of the communication system. The gain offset (310) further is used to determine blocking of an incoming call to the communication system.

公开(公告)号：EP0895688A1

公开(公告)日：1999-02-10

申请号：EP97950580.0

申请日：1997-11-04

Applicant: MOTOROLA, INC.

Inventor： ASHLEY, James, P. ,  PROCTOR, Lee, M.

IPC: H04M1 ,  H04B3 ,  H04M9

CPC classification number: H04M9/082 ,  H04B3/23

Abstract: An improved non-linear processor used in echo cancellation eliminates a comfort noise source (214) and instead inputs a control signal (224) directly into a noise suppression system (403). The noise suppression system (403) uses the control signal (224) to inhibit the iterative update of the background noise estimate when the control signal (224) is active, which prevents any residual echo from biasing the noise estimate provided by the noise suppression system (403). Additionally, the control signal (224) is used by a gain calculator (533) within the noise suppression system (403) to attenuate each frequency band to the maximum allowable amount plus the current residual channel signal-to-noise ratio (SNR). Depending on the implementation, the noise suppression system (403) models the background noise of either a user of the PSTN or a user of a mobile station.