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公开(公告)号：DK0829147T3
公开(公告)日：2008-01-02
申请号：DK96916826
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：AU2007234638A1
公开(公告)日：2007-12-13
申请号：AU2007234638
申请日：2007-11-23
Applicant: QUALCOMM INC
Inventor： PETERZELL PAUL E , SIH GILBERT C , CHALLA RAGHU , HOLENSTEIN CHRISTIAN , KANG INJUP , LI TAO , WALKER BRETT C , RAGHUPATHY ARUN , SEVERSON MATTHEW L
Abstract: An apparatus and method in a wireless communication system, the apparatus comprising: first means for amplifying a received signal; means for cancelling a DC offset in the amplified signal; second means for digitally amplifying the DC offset cancelled signal; and means for measuring the digitally amplified signal and to control the gains of the first and second amplifying means.
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公开(公告)号：DE60035367D1
公开(公告)日：2007-08-09
申请号：DE60035367
申请日：2000-12-20
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , FEVRIER IAN , KANG INYUP , PATRICK CHRISTOPHER
IPC: G06F17/15 , H04B1/7093 , H04B7/26
Abstract: A novel and improved method and apparatus for searching is described. This searcher combines the ability to search multiple offsets of single pilots, such as those found in the IS-95 system, with the ability to search multiple pilots, such as those found in a GPS location determination system. Both types of searching can be done in a single architecture combining the parallel computation features of a matched filter with the flexibility of allowing a variable number of coherent accumulations and a variable number of non-coherent accumulations to be performed at high speed for a wide range of search hypotheses in a resource efficient manner. This invention allows for parallel use of the matched filter structure in a time-sliced manner to search multiple windows. In addition, the searcher allows for optional independent Walsh decovering for each search window. The time-sharing approach allows for optional frequency searching of any offset.
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公开(公告)号：AT334513T
公开(公告)日：2006-08-15
申请号：AT98911808
申请日：1998-03-18
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C , GUPTA KUMAR SAMIR
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：CA2343237C
公开(公告)日：2006-07-04
申请号：CA2343237
申请日：1999-09-02
Applicant: QUALCOMM INC
Inventor： EDMONSTON BRIAN S , SIH GILBERT C , ZOU QIUZHEN
IPC: G01S1/00 , G01S5/00 , G01S19/09 , G01S19/23 , G01S19/24 , G01S19/25 , G01S19/29 , G01S19/30 , G01S19/46 , H04Q7/34 , H04Q7/36 , H04Q7/38
Abstract: The present invention is a novel and improved method and apparatus for performing position location in wireless communications system. In one embodiment the invention comprises a method for performing position location in a subscriber unit in a CDMA wireless communications system having a base station including the step of receiving a position location request during a communication, entering a position location mode, transmitting frames to the base station while performing a position location procedure, and returning to communications mode when said position location procedure has been completed .
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Patent Agency Ranking
公开(公告)号：HK1075140A1
公开(公告)日：2005-12-02
申请号：HK05107254
申请日：2005-08-22
Applicant: QUALCOMM INC
Inventor： MANSOUR ZIAD Z , SIH GILBERT C
IPC: H04B1/7117
Abstract: Techniques for scalable CDMA demodulation with maximum response latency are disclosed. In one aspect, a finger timing unit generates signals indicating cycle boundaries for a plurality of fingers, and an offline processing unit processes stored samples for those fingers in response to the signals. In another aspect, incoming samples are stored in a RAM, while finger timing is maintained using a plurality of counters. The RAM address is stored on symbol boundaries. Symbols for each finger are generated in an offline processing unit, clocked at a higher speed than the finger counters, from a RAM location computed using the stored RAM address. Various other aspects are also presented. These aspects provide for decoupling of the chip rate processing from chip time, which allows a single offline processing unit to service a plurality of fingers, thus reducing additional hardware required to support additional fingers while maintaining maximum latency requirements.
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公开(公告)号：CA2525232A1
公开(公告)日：2004-12-23
申请号：CA2525232
申请日：2004-05-28
Applicant: QUALCOMM INC
Inventor： ABRISHAMKAR FARROKH , BANISTER BRIAN , SIH GILBERT C , EKVETCHAVIT THUNYACHATE
Abstract: This disclosure is directed to techniques for estimating signal-to-noise rat io (SNR) of signals received by a wireless communication device. The techniques take advantage of spatial receive diversity in a wireless communication devi ce to achieve accurate estimates of SNR. In general, a spatial projection wiene r filter function can be applied to incoming symbol estimates to support efficient computation of SNR. The estimated SNR can be used to produce power control commands for use in forward power control.
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公开(公告)号：MXPA02006219A
公开(公告)日：2003-01-28
申请号：MXPA02006219
申请日：2000-12-20
Applicant: QUALCOMM INC
Inventor： SIH GILBERT C
IPC: G06F17/15 , H04B1/7093 , H04B7/26 , H04B1/707
Abstract: Se describe un metodo y un aparato novedosos y mejorados para efectuar busquedas. Esta buscador combina la capacidad de buscar desviaciones multiples de pilotos unicos, tales como aquellas encontradas en el sistema IS-95, con la capacidad de buscar pilotos multiples, tales como aquellos encontrados en el sistema de determinacion de localizacion GPS. Ambos tipos de busquedas pueden efectuarse en una sola arquitectura que combina las caracteristicas de calcula paralelas de un filtro equilibrado con la flexibilidad de permitir que se efectue un numero variable de acumulaciones no coherentes a alta velocidad para una amplia gama de hipotesis de busqueda en una forma eficiente en cuanto a los recursos. Esta invencion permite el uso paralelo de la estructura del filtro equilibrado en una forma tiempo dividido para buscar ventanas multiples. Ademas, el buscador permite el descubrimiento de voz independiente opcional para cada ventana de busqueda. El metodo de tiempo compartido permite la busqueda de frecuencia opcional de cualquier desviacion.
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公开(公告)号：HK1046598A1
公开(公告)日：2003-01-17
申请号：HK02108115
申请日：2002-11-08
Applicant: QUALCOMM INC
Inventor： BUTLER BRIAN K , ZHANG HAITAO , TIEDEMANN EDWARD G JR , ZOU QIUZHEN , SIH GILBERT C , AGRAWAL AVNEESH
IPC: H04W24/02 , H04B1/7075 , H04B1/7077 , H04B1/7115 , H04W52/02 , H04B , H04Q
Abstract: A novel and improved method for performing paging is described. In one embodiment of the invention a searcher is used to detect spread spectrum signals. Samples received RF signals are stored in a sample buffer. During standby mode, the samples are gathered during paging slots assigned to the mobile. A set of searches are performed on the samples, and if pilot signals are detected additional demodulation is performed to detect paging messages. The resulting set of demodulation data may be combined to increase detection. After a page message has been detected, additional demodulation resources may be activated to processes more complete page messages, or other information channels. In one embodiment of the invention, the searcher includes a demodulator to perform quick page detection without the use of finger elements to reduce idle mode power consumption.
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公开(公告)号：BR9914542A
公开(公告)日：2003-01-07
申请号：BR9914542
申请日：1999-10-12
Applicant: QUALCOMM INC
Inventor： BUTLER BRIAN K , ZHANG HAITAO , TIEDEMANN EDWARD G JR , ZOU QIUZHEN , SIH GILBERT C , AGRAWAL AVNEESH
IPC: H04W24/02 , H04B1/7075 , H04B1/7077 , H04B1/7115 , H04W52/02 , H04B1/707 , H04Q7/32
Abstract: A novel and improved method for performing paging is described. In one embodiment of the invention a searcher is used to detect spread spectrum signals. Samples received RF signals are stored in a sample buffer. During standby mode, the samples are gathered during paging slots assigned to the mobile. A set of searches are performed on the samples, and if pilot signals are detected additional demodulation is performed to detect paging messages. The resulting set of demodulation data may be combined to increase detection. After a page message has been detected, additional demodulation resources may be activated to processes more complete page messages, or other information channels. In one embodiment of the invention, the searcher includes a demodulator to perform quick page detection without the use of finger elements to reduce idle mode power consumption.
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