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公开(公告)号：ID24156A
公开(公告)日：2000-07-13
申请号：ID991099
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：CA2351383A1
公开(公告)日：2000-06-02
申请号：CA2351383
申请日：1999-11-18
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , AGRAWAL AVNEESH , ZOU QUIZHEN
Abstract: One or more loadable PN generators are controlled by a DSP or microprocessor in conjunction with a free-running counter which maintains a reference offse t count. The PN generator will typically be part of a finger or searcher. Each PN generator is comprised of a loadable linear feedback shift register (LFSR ) or its equivalent, a loadable counter for maintaining an index of the state of that particular PN generator, and a slew control device capable of receiving a slew command and controlling the LFSR and index counter to enact an advance or a retard of a certain offset distance. The speed increase is effected by DSP control. A table of LFSR states and corresponding index numbers are stored i n memory. These LFSR states will subdivide the total possible number of possib le states. It is advantageous to evenly space the stored states around the PN circle. The fast slewing is enabled by the DSP in two-step process. First th e PN generator is loaded such that it "jumps" to the closest state using the table, then the PN generator's slew control is used to slew the rest of the way.
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公开(公告)号：AU5908399A
公开(公告)日：2000-03-27
申请号：AU5908399
申请日：1999-09-03
Applicant: QUALCOMM INC
Inventor： GARDNER WILLIAM , AGRAWAL AVNEESH , SIH GILBERT C , ZOU QIUZHEN , KANG INYUP
IPC: G01S19/30 , G01S1/00 , G01S5/00 , G01S5/14 , G01S19/23 , G01S19/24 , G01S19/25 , G01S19/29 , G01S19/37 , H04Q7/34 , H04Q7/38 , G01S1/04
Abstract: The present invention is a novel and improved method and apparatus for performing position location in wireless communications system. One embodiment comprises a method for performing position location in a wireless communication system using a set of signals transmitted from a set of satellites including the steps of receiving signal samples, rotating an acquisition code by a first rotation amount yielding a rotated acquisition code, despreading said signal samples using rotated acquisition code yielding despread data, accumulating said despread data over a first duration yielding partially accumulated data, rotating said partially accumulated data by a second rotation amount yielding rotated data and accumulating said rotated data.
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公开(公告)号：CA2343741A1
公开(公告)日：2000-03-16
申请号：CA2343741
申请日：1999-09-03
Applicant: QUALCOMM INC
Inventor： ZOU QUIZHEN , SIH GILBERT C
Abstract: The present invention is a novel and improved method and apparatus for performing position location in wireless communications system. One embodime nt of the invention comprises a method of performing position location in a wireless subscriber unit having a local oscillator, including the steps of receiving a position location request, acquiring a timing signal when a sufficient period of time has elapsed since the local oscillator has been corrected and correcting said local oscillator using a correction signal bas ed on said timing signal, substantially freezing the correction signal, performing a position location procedure using the local oscillator with the correction signal applied, and ending said position location procedure.
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公开(公告)号：CA2342235A1
公开(公告)日：2000-03-16
申请号：CA2342235
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 embodime nt of the invention comprises a method for performing position location includi ng the steps of receiving a set of higher resolution sample data at a resolutio n interval, accumulating said higher resolution sample data over a chip interv al 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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Patent Agency Ranking
公开(公告)号：HK1015215A1
公开(公告)日：1999-10-08
申请号：HK98116165
申请日：1998-12-28
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：HK1011119A1
公开(公告)日：1999-07-02
申请号：HK98110094
申请日：1998-08-21
Applicant: QUALCOMM INC
Inventor： ANTONIO FRANKLIN P , SIH GILBERT C
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：NO992358A
公开(公告)日：1999-06-02
申请号：NO992358
申请日：1999-05-14
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , JOHN JOHNNY K
CPC classification number: H04N1/32708 , H04M1/725 , H04N1/32704 , H04N1/32715 , H04N1/32721
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公开(公告)号：AU5962498A
公开(公告)日：1998-08-25
申请号：AU5962498
申请日：1998-01-27
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , MAURO ANTHONY P
Abstract: A method and apparatus for controlling various functional elements in a digital telephone system using state determination from an echo canceller. An echo canceller is used to evaluate which one of five talk states two speakers are engaged in during a telephone conversation. This state determination information is used to control a tone detector function, a noise suppressor function, an adaptive equalizer function, a transmission mute function, and a vocoder encoder function within a vocoder. During the talk state where the far-end speaker is active and the near-end speaker is inactive, the echo canceller provides a signal which disables background noise estimates from being performed in the noise suppressor and the vocoder encoder. The same signal is used to disable the tone detector and to enable the transmission mute function during this talk state.
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公开(公告)号：ZA98761B
公开(公告)日：1998-08-17
申请号：ZA98761
申请日：1998-01-29
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , MAURO ANTHONY P
Abstract: A method and apparatus for controlling various functional elements in a digital telephone system using state determination from an echo canceller. An echo canceller is used to evaluate which one of five talk states two speakers are engaged in during a telephone conversation. This state determination information is used to control a tone detector function, a noise suppressor function, an adaptive equalizer function, a transmission mute function, and a vocoder encoder function within a vocoder. During the talk state where the far-end speaker is active and the near-end speaker is inactive, the echo canceller provides a signal which disables background noise estimates from being performed in the noise suppressor and the vocoder encoder. The same signal is used to disable the tone detector and to enable the transmission mute function during this talk state.
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