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公开(公告)号：AU6243699A
公开(公告)日：2000-03-27
申请号：AU6243699
申请日：1999-09-03
Applicant: QUALCOMM INC
Inventor： ZOU QUIZHEN , SIH GILBERT C , KANG INYUP
IPC: G01S1/00 , G01S1/04 , G01S5/00 , G01S19/23 , G01S19/25 , G01S19/30 , G01S19/48 , H04M1/725 , H04Q7/34 , G01S5/14
Abstract: A mobile device (10) comprises a receiver and a coherent integrator (104), wherein the receiver is configured to receive a first signal from a satellite, the first signal including a navigation message. The coherent integrator is configured to coherently integrate first signal samples for a particular coherent integration interval. When the coherent integration interval straddles a data boundary of the navigation message, the coherent integration is divided into a section before the data boundary of the navigation message and a section after the data boundary of the navigation message
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公开(公告)号：AU5809599A
公开(公告)日：2000-03-27
申请号：AU5809599
申请日：1999-09-02
Applicant: QUALCOMM INC
Inventor： GLAZKO SERGUEI A , SIH GILBERT C , ZOU QIUZHEN
Abstract: The present invention is a novel and improved method and apparatus for performing position location in wireless communications system. One embodiment of the invention comprises a method for performing position location including the steps of receiving a set of higher resolution sample data at a resolution interval, accumulating said higher resolution sample data over a chip interval yielding accumulation sums, and correlating said accumulation sums with a correlation code at a set of offsets which are separated by said resolution interval.
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公开(公告)号：RO114392B1
公开(公告)日：1999-03-30
申请号：RO9400874
申请日：1993-09-24
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C
IPC: G10L19/012 , H04M1/60 , H04B3/23 , H04M9/08
Abstract: An echo canceller and method for cancelling in a return channel signal an echoed receive channel signal where the echoed receive channel signal is combined by an echo channel with an input return channel signal. The echo canceller has a first filter which generates first filter coefficients, generates a first echo estimate signal with the first filter coefficients, and updates the first filter coefficients in response to a first filter control signal. A first summer subtracts the first echo estimate signal from a combined return channel and echo receive channel signal to generate a first echo residual signal. A second filter generates second filter coefficients, generates a second echo estimate signal with the second filter coefficients, and updates the second filter coefficients in response to a second filter control signal. A second summer subtracts the second echo estimate signal from the combined signal to generate a second echo residual signal, and provides upon the return channel the second echo residual signal. A control unit determines from the receive channel signal, the combined signal, and the first and second echo residual signals, one of a plurality of control states wherein a first control state is indicative of a receive channel signal above a first predetermined energy level, wherein when the control unit is in the first control state it generates the first control signal and generates the second control signal when at least one of a first energy ratio of the first echo residual signal and the combined signal and a second energy ratio of the second echo residual signal and the combined signal exceed a predetermined level.
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公开(公告)号：AU6567898A
公开(公告)日：1998-10-12
申请号：AU6567898
申请日：1998-03-18
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , GUPTA SAMIR KUMAR
Abstract: A method and apparatus for canceling both earseal and hybrid echo in a Wireless Local Loop telephone system is disclosed. The present invention operates within a subscriber station having a plurality of telephone inputs, one of which is a dedicated handset and at least one other input being a standard analog telephone. During a conference call between a far end speaker and two near end speakers, the far end speaker may hear an echo of his own voice due to an earseal echo generated by the dedicated handset and a hybrid echo generated by a 4-to-2 wire hybrid interface within the subscriber station. In accordance with the present invention, two distinct echo cancellers are used in the subscriber station to reduce the two types of echo. A first echo canceller is optimized to remove the earseal echo generated at the dedicated handset while a second echo canceller is optimized to remove the hybrid echo generated at the 4-to-2 wire hybrid. The two echo cancellers operate independently such that neither echo canceller need adapt its filter coefficients when a change in the echo channel characteristics occur, such as when a speaker hangs up or another speaker joins the conversation.
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公开(公告)号：AU692487B2
公开(公告)日：1998-06-11
申请号：AU8096294
申请日：1994-10-27
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , ANTONIO FRANKLIN P
Abstract: An apparatus that automatically adjusts the adaptation block size for a least-mean square (LMS) adaptive filter depending on the input signal-to-noise ratio (SNR) is disclosed. The apparatus monitors the instantaneous SNR and continually adjusts the block size to provide high noise immunity, thereby increasing the convergence speed of the filter and decreasing the asymptotic mean-square error. An exemplary embodiment of the present invention is presented in the context of acoustic echo cancellation, though it is noted that the adaptive filter of the present invention is useful in any environment in which the noise characteristics are subject to change.
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Patent Agency Ranking
公开(公告)号：NZ302523A
公开(公告)日：1998-01-26
申请号：NZ30252396
申请日：1996-01-25
Applicant: QUALCOMM INC
Inventor： WEAVER LINDSAY A , LAM S KATHERINE , JACOBS PAUL E , GARDNER WILLIAM R , DEJACO ANDREW P , SIH GILBERT C
IPC: G10L11/02 , G10L19/00 , G10L19/14 , H04B7/26 , H04B14/04 , H04Q11/04 , H04W88/18 , H03M13/00 , G10L5/00 , 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.
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公开(公告)号：AU5957396A
公开(公告)日：1996-12-18
申请号：AU5957396
申请日：1996-05-31
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C
Abstract: A system and method for detecting convergence in an echo canceller prevent false convergence from occurring as a result of receiving only tones in an input signal. An adaptive filter is used in an echo canceller to estimate an echo signal produced by an unknown echo channel. The estimated echo signal is subtracted from the return signal to remove the echo produced by the unknown echo channel. To prevent the echo canceller from falsely converging on a signal which contains only tones a system and method are provided for detecting the presence of tones in the absence of other frequencies. Filter taps of the adaptive filter are filtered to produce a filtered signal. The amount of energy in the filtered signal is compared to the amount of energy in the unfiltered filter taps to determine whether only tones have been present. If only tones have been present, the echo canceller is not allowed to reduce the adaptation step size of the adaptive filter.
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公开(公告)号：FI961824A
公开(公告)日：1996-06-28
申请号：FI961824
申请日：1996-04-29
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , ANTONIO FRANKLIN P
Abstract: An apparatus that automatically adjusts the adaptation block size for a least-mean square (LMS) adaptive filter depending on the input signal-to-noise ratio (SNR) is disclosed. The apparatus monitors the instantaneous SNR and continually adjusts the block size to provide high noise immunity, thereby increasing the convergence speed of the filter and decreasing the asymptotic mean-square error. An exemplary embodiment of the present invention is presented in the context of acoustic echo cancellation, though it is noted that the adaptive filter of the present invention is useful in any environment in which the noise characteristics are subject to change.
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公开(公告)号：ZA9408430B
公开(公告)日：1995-06-29
申请号：ZA9408430
申请日：1994-10-26
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , ANTONIO FRANKLIN P
CPC classification number: H04B3/23 , H03H21/0012
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公开(公告)号：AU660243B2
公开(公告)日：1995-06-15
申请号：AU5291893
申请日：1993-09-24
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C
Abstract: An echo canceller and method for cancelling in a return channel signal an echoed receive channel signal where the echoed receive channel signal is combined by an echo channel with an input return channel signal. The echo canceller has a first filter which generates first filter coefficients, generates a first echo estimate signal with the first filter coefficients, and updates the first filter coefficients in response to a first filter control signal. A first summer subtracts the first echo estimate signal from a combined return channel and echo receive channel signal to generate a first echo residual signal. A second filter generates second filter coefficients, generates a second echo estimate signal with the second filter coefficients, and updates the second filter coefficients in response to a second filter control signal. A second summer subtracts the second echo estimate signal from the combined signal to generate a second echo residual signal, and provides upon the return channel the second echo residual signal. A control unit determines from the receive channel signal, the combined signal, and the first and second echo residual signals, one of a plurality of control states wherein a first control state is indicative of a receive channel signal above a first predetermined energy level, wherein when the control unit is in the first control state it generates the first control signal and generates the second control signal when at least one of a first energy ratio of the first echo residual signal and the combined signal and a second energy ratio of the second echo residual signal and the combined signal exceed a predetermined level.
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