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公开(公告)号：AU2003256623C1
公开(公告)日：2009-05-28
申请号：AU2003256623
申请日：2003-07-18
Applicant: QUALCOMM INC
Inventor： CORBATON IVAN JESUS FERNANDEZ , JAYARAMAN SRIKANT , SMEE JOHN E
Abstract: A method and apparatus for a decision feedback equalizer wherein a correction term is used to compensate for slicer errors, thus avoiding error propagation. Filter coefficients for the equalizer are selected so as to minimize a cost function for the equalizer, including a correction term as a function of the energy of the filter coefficients. The equalizer includes a coefficient generator responsive to the correction term. One embodiment estimates a transmitted symbol from a received sample as a function of Signal-to-Interference and Noise Ratio (SINR) of the received sample. The received sample is quantized and mapped to a region of a grid overlaid on the transmitted symbol constellation. The region may correspond to a symbol estimate value or may be processed further to obtain a symbol estimate value.
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公开(公告)号：AT418195T
公开(公告)日：2009-01-15
申请号：AT03729592
申请日：2003-01-07
Applicant: QUALCOMM INC
Inventor： JAYARAMAN SRIKANT , CORBATON IVAN , SMEE JOHN
IPC: H03M13/01 , H04L1/00 , H04B1/7105 , H04B1/712 , H04L1/02
Abstract: Methods and apparatus are presented herein for determining log likelihood ratios (LLRs) for code symbols. Pilot and code symbols are transmitted over diversity channels, which can be modeled as a slowly time varying system. A formulation for a multipath gain vector is derived herein based on the slowly time varying model. The multipath gain vector is then solved using iterative procedures. Using the solved multipath gain vector, the LLRs for code symbols are computed.
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公开(公告)号：SI1792462T1
公开(公告)日：2008-12-31
申请号：SI200530413
申请日：2005-09-16
Applicant: QUALCOMM INC
Inventor： NAMGOONG JUNE , XU HAO , BLACK PETER J , JAYARAMAN SRIKANT
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公开(公告)号：AU2002363722C1
公开(公告)日：2008-12-11
申请号：AU2002363722
申请日：2002-11-08
Applicant: QUALCOMM INC
Inventor： FERNANDEZ-CORBATON IVAN JESUS , SMEE JOHN , JAYARAMAN SRIKANT
Abstract: A carrier recovery method and apparatus using multiple stages of carrier frequency recovery are disclosed. A receiver uses multiple frequency generation sources to generate carrier signals used to downconvert a received signal. An analog frequency reference having a wide frequency range and coarse frequency resolution is used in conjunction with a digital frequency reference having a narrow frequency range and fine frequency resolution. The multiple carrier signals are multiplied by a received signal to effect a multi-stage downconversion, resulting in a baseband signal. A frequency tracking module measures the residual frequency error present in the baseband signal. The measured residual frequency error is then used to adjust the frequencies of the carrier signals generated by the multiple frequency generation sources.
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公开(公告)号：DE60222676T2
公开(公告)日：2008-06-12
申请号：DE60222676
申请日：2002-07-31
Applicant: QUALCOMM INC
Inventor： JAYARAMAN SRIKANT , CORBATON IVAN JESUS FERNANDEZ , SMEE JOHN E
IPC: H04L25/03 , H04B1/707 , H04B1/7115 , H04B1/7117 , H04B1/712 , H04B7/005 , H04L7/02
Abstract: A weighted mean arrival time determines a delay offset of a fractionally spaced equalizer (350). The weighted mean arrival time is determined using path arrival times and energies from a Rake receiver (604). The difference between a weighted mean arrival time and a current delay offset is set to a difference X, in units of the equalizer tap spacing (608). If the difference X is greater than or equal to 1 or less than or equal to -1, then the current delay offset is updated by an incremental delay offset (610), (612), (614), (616) and the equalizer filter coefficients are shifted by a number of tap spacings (618), (620). Otherwise, the current delay offset is not updated and the filter coefficients of the fractionally spaced equalizer are not shifted (350). Adaptation of the filter coefficients and updates of the delay offset of the equalizer occur only during pilot bursts so as to minimize adaptation transients.
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Patent Agency Ranking
公开(公告)号：DE60222676D1
公开(公告)日：2007-11-08
申请号：DE60222676
申请日：2002-07-31
Applicant: QUALCOMM INC
Inventor： JAYARAMAN SRIKANT , CORBATON IVAN JESUS FERNANDEZ , SMEE JOHN E
IPC: H04L25/03 , H04B1/707 , H04B1/7115 , H04B1/7117 , H04B1/712 , H04B7/005 , H04L7/02
Abstract: A weighted mean arrival time determines a delay offset of a fractionally spaced equalizer (350). The weighted mean arrival time is determined using path arrival times and energies from a Rake receiver (604). The difference between a weighted mean arrival time and a current delay offset is set to a difference X, in units of the equalizer tap spacing (608). If the difference X is greater than or equal to 1 or less than or equal to -1, then the current delay offset is updated by an incremental delay offset (610), (612), (614), (616) and the equalizer filter coefficients are shifted by a number of tap spacings (618), (620). Otherwise, the current delay offset is not updated and the filter coefficients of the fractionally spaced equalizer are not shifted (350). Adaptation of the filter coefficients and updates of the delay offset of the equalizer occur only during pilot bursts so as to minimize adaptation transients.
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公开(公告)号：BRPI0417253A
公开(公告)日：2007-03-06
申请号：BRPI0417253
申请日：2004-12-03
Applicant: QUALCOMM INC
Abstract: Systems and methods for adaptively allocating resources between a dedicated reference signal and a traffic signal are disclosed. In an exemplary embodiment, a wireless communication system 100 includes a base station 404. The base station 404 includes a receiver 428 that receives a quality metric 432 from a remote station 106. The quality metric 432 indicates the quality of a signal transmitted from the base station 404 and received by the remote station 106. The base station 404 also includes a resource allocation component 434 that uses the quality metric 432 to allocate a resource between the traffic signal 422 and the dedicated reference signal 418. The base station 404 also includes a transmitter 426 that transmits the traffic signal 422 and the dedicated reference signal 418 to the remote station 106.
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公开(公告)号：CZ2005704A3
公开(公告)日：2006-03-15
申请号：CZ2005704
申请日：2005-01-20
Applicant: QUALCOMM INC
Inventor： GROB MATTHEW S , BLACK PETER J , JAYARAMAN SRIKANT , JACOBS PAUL E
Abstract: Synchronizovaný broadcast vysílá stejný broadcastobsah pouzitím stejné nosné z více vysílacu. Kazdý vysílac pouzije stejný kód rozprostrení pro vysílání typu broadcast. V komunikacním systému s rozprostreným spektrem s casove multiplexovaným prímýmlinkem se vlozí synchronizované broadcast vysílání do broadcast slotu. Jedno provedení pouzívá pro synchronizovaný broadcast nosnou ortogonálního frekvencního multiplexu (OFDM). OFDM prijímac se potom pouzije ke zpracování prijatého synchronizovaného broadcast vysílání. Alternativní provedení pouzívá broadcast kód pseudonáhodného sumu (PN) pro pouzití více vysílaci. Potom se k odhadu synchronizovaného broadcast vysílání pouzije ekvalizér.
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公开(公告)号：CA2570273A1
公开(公告)日：2005-12-29
申请号：CA2570273
申请日：2005-06-14
Applicant: QUALCOMM INC
Inventor： XU HAO , BLACK PETER J , NAMGOONG JUNE , JAYARAMAN SRIKANT
IPC: H04L25/02
Abstract: A pilot assisted channel estimation process. A receiver may be configured to estimate the impulse response of a channel from a signal having pilot tones and spread-spectrum pilot signals. The receiver estimates the response of the channel from the pilot tones, and adapts the length of delay the channel response is estimated based on the spread-spectrum pilot signals.
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公开(公告)号：NO20055252D0
公开(公告)日：2005-11-08
申请号：NO20055252
申请日：2005-11-08
Applicant: QUALCOMM INC
Inventor： JACOBS PAUL E , BLACK PETER J , JAYARAMAN SRIKANT , GROB MATTHEW S
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