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公开(公告)号：DE69904957D1
公开(公告)日：2003-02-20
申请号：DE69904957
申请日：1999-09-03
Applicant: QUALCOMM INC
Inventor： GARDNER WILLIAM , AGRAWAL AVNEESH , SIH 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：DE69620585T2
公开(公告)日：2002-11-28
申请号：DE69620585
申请日：1996-01-25
Applicant: QUALCOMM INC
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：DE69620585D1
公开(公告)日：2002-05-16
申请号：DE69620585
申请日：1996-01-25
Applicant: QUALCOMM INC
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：DE69735635D1
公开(公告)日：2006-05-18
申请号：DE69735635
申请日：1997-11-13
Applicant: QUALCOMM INC
Abstract: A novel and improved method and apparatus for providing an interface to a digital wireless telephone system compatible with standard analog wire line telephones and analog wire line fax machines is disclosed. During a telephone call, a fax detector (11) monitors the incoming data for fax signals. If a fax is detected, the data processor (12) switches from processing the data as if it were voice to processing it as fax. In addition, the remote station is sent a signal notifying it to process the data as fax rather than voice. The fax detector (11) operates by detecting the preamble of a V.21 message, present at the beginning of every fax call. Energy is measured in both frequencies of the BFSK signals. A decision is made by analyzing these energies and locating a specific pattern which repeats itself a sufficient number of times.
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公开(公告)号：DE69924867D1
公开(公告)日：2005-05-25
申请号：DE69924867
申请日：1999-11-18
Applicant: QUALCOMM INC
Inventor： ZOU QUIZHEN , SIH C , AGRAWAL AVNEESH
Abstract: A novel and improved method and apparatus for a fast-slewing pseudorandom noise sequence generator is described. One or more loadable PN generators are controlled by a DSP or microprocessor in conjunction with a free-running counter which maintains a reference offset count. The PN generator will typically be part of a finger or searcher. The DSP or microprocessor may assist in other finger or searcher functions as well as the slew function, and can control one or more fingers and/or searchers. 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.
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Patent Agency Ranking
公开(公告)号：DE69904957T2
公开(公告)日：2004-01-08
申请号：DE69904957
申请日：1999-09-03
Applicant: QUALCOMM INC
Inventor： GARDNER WILLIAM , AGRAWAL AVNEESH , SIH 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：DE69431923D1
公开(公告)日：2003-01-30
申请号：DE69431923
申请日：1994-10-27
Applicant: QUALCOMM INC
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：DE69331223T2
公开(公告)日：2002-06-13
申请号：DE69331223
申请日：1993-09-24
Applicant: QUALCOMM INC
Inventor： SIH C
IPC: H04M1/60 , G10L19/012 , 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：DE69331223D1
公开(公告)日：2002-01-10
申请号：DE69331223
申请日：1993-09-24
Applicant: QUALCOMM INC
Inventor： SIH C
IPC: H04M1/60 , G10L19/012 , 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：DE69835347T2
公开(公告)日：2007-07-26
申请号：DE69835347
申请日：1998-03-18
Applicant: QUALCOMM INC
Inventor： SIH C , GUPTA 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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