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    21.
    发明专利
    未知

    公开(公告)号：BR0210559A

    公开(公告)日：2004-10-05

    申请号：BR0210559

    申请日：2002-06-17

    Applicant: QUALCOMM INC

    Inventor： JALALI AHMAD ,  SMEE JOHN E ,  WALLACE MARK

    IPC: H04J11/00 ,  H04J3/00 ,  H04J99/00 ,  H04L1/00 ,  H04L1/06 ,  H04L5/22 ,  H04L25/02 ,  H04L25/03 ,  H04Q7/28 ,  H04L27/26

    Abstract: A method of wireless communication is disclosed, the method comprising transmitting at least one pilot reference from a plurality of antennas of a base station; receiving, at the base station, calibration information for a forward link from a terminal responsive to the at least one pilot reference; determining, at the base station, calibration information for a reverse link based upon signals transmitted from the terminal; and generating a calibration function for transmission to the terminal based upon the calibration information for the forward link and calibration information for the reverse link.

    Method and apparatus for varying the length of an adaptive equalizer based on doppler frequency
    24.
    发明专利
    Method and apparatus for varying the length of an adaptive equalizer based on doppler frequency 未知

    公开(公告)号：AU2002331899A1

    公开(公告)日：2003-04-07

    申请号：AU2002331899

    申请日：2002-09-24

    Applicant: QUALCOMM INC

    Inventor： JAYARAMAN SRIKANT ,  FERNANDEZ-CORBATON IVAN JESUS ,  SMEE JOHN E

    IPC: H04B7/005 ,  H04B3/06 ,  H04L25/03

    Abstract: Systems and methods according to the present invention are described for adjusting the number of taps in an adaptive equalizer over time as the rate of change of a communications channel varies. The number of taps or "equalizer length" is adjusted based on an estimate of the Doppler frequency between the devices communicating over a channel. The Doppler frequency is reflective of the rate of change of the communications channel. Greater Doppler frequencies indicate a more quickly varying channel, and vice versa. It is therefore desirable to change the equalizer length (by adding or dropping taps) based on a measurement of the Doppler frequency. Equalizer length is increased as the Doppler frequency decreases. Conversely, equalizer length is decreased as the Doppler frequency increases. This enables the equalizer to achieve a better compromise between the competing goals of adaptation speed (less taps) and ISI reduction (more taps).

    método e equipamento para equalização de realimentação de decisão híbrida
    25.
    发明专利
    método e equipamento para equalização de realimentação de decisão híbrida 未知

    公开(公告)号：BRPI0312747B1

    公开(公告)日：2016-11-22

    申请号：BR0312747

    申请日：2003-07-18

    Applicant: QUALCOMM INC

    Inventor： FERNANDEZ-CORBATON IVAN JESUS ,  SMEE JOHN E ,  JAYARAMAN SRIKANT

    IPC: H04L25/00 ,  H04L27/01 ,  H04B7/005 ,  H04L25/03

    Abstract: "método e equipamentopara equalização de realimentação de decisão híbrida" descreve-se um método e um equipamento para um equalizador de realimentação de decisão, nos quais um termo de correção é utilizado para compensar erros de corte, evitando-se assim a programação de erros. os coeficientes de filtro para o equalizador são selecionados de modo a se minimizar uma função de custo para o equalizador, que inclui um termo de correção como uma função da energia dos coeficientes de filtro. o equalizador inclui um gerador de coeficientes que responde ao termo de correção. uma modalidade estima um símbolo transmitido a partir de uma amostra recebida como uma função da relação sinal/interferência e ruído (sinr) da amostra recebida. a amostra recebida é quantizada e mapeada em uma região de uma grade sobreposta na constelação de símbolos transmitida. a região pode corresponder a um valor de estimativa de símbolo ou pode ser processada adicionalmente de modo a se obter um valor de estimativa de símbolo.

    METHOD AND APPARATUS FOR HYBRID DECISION FEEDBACK EQUALIZATION
    27.
    发明专利
    METHOD AND APPARATUS FOR HYBRID DECISION FEEDBACK EQUALIZATION 未知

    公开(公告)号：CA2493106C

    公开(公告)日：2014-11-25

    申请号：CA2493106

    申请日：2003-07-18

    Applicant: QUALCOMM INC

    Inventor： JAYARAMAN SRIKANT ,  FERNANDEZ CORBATON IVAN JESUS ,  SMEE JOHN E

    IPC: H04L25/03 ,  H04L27/01 ,  H04B7/005 ,  H04L25/00

    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.

    PILOT TRANSMISSION SCHEMES FOR WIRELESS MULTI-CARRIER COMMUNICATION SYSTEMS
    28.
    发明专利
    PILOT TRANSMISSION SCHEMES FOR WIRELESS MULTI-CARRIER COMMUNICATION SYSTEMS 未知

    公开(公告)号：CA2512551C

    公开(公告)日：2013-01-15

    申请号：CA2512551

    申请日：2004-01-07

    Applicant: QUALCOMM INC

    Inventor： SMEE JOHN E ,  WALTON JAY RODNEY ,  MALLADI DURGA PRASAD

    IPC: H04L27/26 ,  H04B7/06 ,  H04B7/08 ,  H04L1/00 ,  H04L1/06 ,  H04L25/02 ,  H04L25/03

    Abstract: Pilot transmission schemes suitable for use in wireless multi-carrier (e.g., OFDM) communication systems. These pilot transmission schemes may utilize frequency, time, or both frequency and time orthogonality to achieve orthogonality among the pilots transmitted by multiple base stations on the downlink. Frequency orthogonality is achieved by transmitting pilots on disjoint sets of subbands. Time orthogonality is achieved by transmitting pilots using different orthogonal codes (e.g., Walsh codes). The pilots may also be scrambled with different scrambling codes, which are used to randomize pilot interference and to enable identification of the transmitters of these pilots. Pilot interference cancellation may be performed to improve performance since subbands used for data transmission by one transmitter may also be used for pilot transmission by another transmitter. Pilot interference is estimated and then subtracted from received symbols to obtain pilot-canceled symbols having improved quality.

    Method and apparatus for hybrid decision feedback equalization
    29.
    发明专利
    Method and apparatus for hybrid decision feedback equalization 未知

    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

    IPC: H04L27/01 ,  H04B7/005 ,  H04L25/00 ,  H04L25/03

    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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