BR0016127A - Method and apparatus for suppressing background noise in a communication system - Google Patents

Method and apparatus for suppressing background noise in a communication system

Info

Publication number
BR0016127A
BR0016127A BR0016127-6A BR0016127A BR0016127A BR 0016127 A BR0016127 A BR 0016127A BR 0016127 A BR0016127 A BR 0016127A BR 0016127 A BR0016127 A BR 0016127A
Authority
BR
Brazil
Prior art keywords
channel
snr
communication system
gain
noise
Prior art date
Application number
BR0016127-6A
Other languages
Portuguese (pt)
Inventor
Tenkasi V Ramabadran
James P Ashley
Original Assignee
Motorola Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Inc filed Critical Motorola Inc
Publication of BR0016127A publication Critical patent/BR0016127A/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/005—Control of transmission; Equalising
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04S—STEREOPHONIC SYSTEMS 
    • H04S1/00—Two-channel systems
    • H04S1/007—Two-channel systems in which the audio signals are in digital form

Abstract

"MéTODO E APARELHO PARA SUPRIMIR O RUìDO ACúSTICO DE SEGUNDO PLANO EM UM SISTEMA DE COMUNICAçãO". Método e aparelho para suprimir o ruído acústico de segundo plano em um sistema de comunicação. O nível de relação sinal-ruído (SNR) operacional é avaliado com confiabilidade dos valores da energia de canal (293) e da energia de ruído de segundo plano (294) por um estimador de nível SNR (295). Um fator de ganho mínimo e uma inclinação de ganho são adaptados (290) dependendo do nível SNR operacional. Utilizando esses valores adaptados e o SNR de canal, o ganho de canal é selecionado (233). Quando o SNR de canal estiver abaixo de determinado limite, o canal é completamente assemelhado a ruído e o fator de ganho selecionado é mínimo de modo que o canal é atenuado ao máximo. Quando o SNR de canal é relativamente alto, o ganho de canal selecionado é 0 dB. Para valores intermediários do SNR de canal, o fator de ganho selecionado situa-se entre o mínimo e 0 dB."METHOD AND APPARATUS TO SUPPRESS THE ACOUSTIC NOISE OF THE SECOND PLAN IN A COMMUNICATION SYSTEM". Method and apparatus for suppressing background acoustic noise in a communication system. The operational signal-to-noise ratio (SNR) level is reliably assessed for the values of channel energy (293) and background noise energy (294) by an SNR level estimator (295). A minimum gain factor and a gain slope are adapted (290) depending on the operational 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 resembled to noise and the selected gain factor is minimal so that the channel is attenuated to the maximum. When the channel SNR is relatively high, the selected channel gain is 0 dB. For intermediate values of the channel SNR, the selected gain factor is between the minimum and 0 dB.

BR0016127-6A 1999-12-03 2000-11-30 Method and apparatus for suppressing background noise in a communication system BR0016127A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US16895599P 1999-12-03 1999-12-03
US72393900A 2000-11-28 2000-11-28
PCT/US2000/032610 WO2001041334A1 (en) 1999-12-03 2000-11-30 Method and apparatus for suppressing acoustic background noise in a communication system

Publications (1)

Publication Number Publication Date
BR0016127A true BR0016127A (en) 2002-08-06

Family

ID=26864619

Family Applications (1)

Application Number Title Priority Date Filing Date
BR0016127-6A BR0016127A (en) 1999-12-03 2000-11-30 Method and apparatus for suppressing background noise in a communication system

Country Status (5)

Country Link
EP (1) EP1238479A4 (en)
JP (1) JP2003517761A (en)
KR (1) KR20020056957A (en)
BR (1) BR0016127A (en)
WO (1) WO2001041334A1 (en)

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5744338A (en) * 1980-08-29 1982-03-12 Victor Co Of Japan Ltd Noise reduction device
US4628529A (en) * 1985-07-01 1986-12-09 Motorola, Inc. Noise suppression system
US4630305A (en) * 1985-07-01 1986-12-16 Motorola, Inc. Automatic gain selector for a noise suppression system
FI92535C (en) * 1992-02-14 1994-11-25 Nokia Mobile Phones Ltd Noise reduction system for speech signals
US5432859A (en) * 1993-02-23 1995-07-11 Novatel Communications Ltd. Noise-reduction system
US5544250A (en) * 1994-07-18 1996-08-06 Motorola Noise suppression system and method therefor
US5706395A (en) * 1995-04-19 1998-01-06 Texas Instruments Incorporated Adaptive weiner filtering using a dynamic suppression factor
US5659622A (en) * 1995-11-13 1997-08-19 Motorola, Inc. Method and apparatus for suppressing noise in a communication system
US6104993A (en) * 1997-02-26 2000-08-15 Motorola, Inc. Apparatus and method for rate determination in a communication system
US6088668A (en) * 1998-06-22 2000-07-11 D.S.P.C. Technologies Ltd. Noise suppressor having weighted gain smoothing

Also Published As

Publication number Publication date
EP1238479A4 (en) 2005-07-27
WO2001041334A1 (en) 2001-06-07
EP1238479A1 (en) 2002-09-11
KR20020056957A (en) 2002-07-10
JP2003517761A (en) 2003-05-27

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Legal Events

Date Code Title Description
B08F Application fees: application dismissed [chapter 8.6 patent gazette]

Free format text: REFERENTE A 6A,7A ANUIDADE.

B08K Patent lapsed as no evidence of payment of the annual fee has been furnished to inpi [chapter 8.11 patent gazette]

Free format text: REFERENTE AO DESPACHO PUBLICADO NA RPI 1962 DE 12/08/2008.