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21 records (took 0.021 seconds)

    11.
    发明专利
    未知

    公开(公告)号：BRPI0608230A2

    公开(公告)日：2009-11-24

    申请号：BRPI0608230

    申请日：2006-03-13

    Applicant: QUALCOMM INC

    Inventor： GUPTA ALOK ,  CHUNG SEONG-TAEK ,  MURTHY VINAY ,  LING FUYUN

    IPC: H04L27/26 ,  G06F1/03 ,  H04L27/38

    Abstract: Techniques for performing frequency control in an OFDM system are described. In one aspect, frequency acquisition is performed based on a received pilot, and frequency tracking is performed based on received OFDM symbols. For frequency acquisition, an initial frequency error estimate may be derived based on the received pilot, and an automatic frequency control (AFC) loop may be initialized with the initial frequency error estimate. For frequency tracking, a frequency error estimate may be derived for each received OFDM symbol, and the AFC loop may be updated with the frequency error estimate. Frequency error in input samples is corrected by the AFC loop with the initial frequency error estimate as well as the frequency error estimate for each received OFDM symbol. In another aspect, a variable number of samples of a received OFDM symbol are selected, e.g., based on the received OFDM symbol timing, for use for frequency error estimation.

    METODO Y SISTEMA PARA EL CONTROL DE GANANCIA AUTOMATICO CON SELECCION INTELIGENTE DE MUESTRAS DE SENAL
    12.
    发明专利
    METODO Y SISTEMA PARA EL CONTROL DE GANANCIA AUTOMATICO CON SELECCION INTELIGENTE DE MUESTRAS DE SENAL 未知

    公开(公告)号：AR060275A1

    公开(公告)日：2008-06-04

    申请号：ARP070101405

    申请日：2007-04-03

    Applicant: QUALCOMM INC

    Inventor： MURTHY VINAY ,  KRISHNAMOORTHI RAGHURAMAN

    IPC: H03G3/30

    Abstract: Dispositivo de comunicacion que incluye un conjunto de circuitos de control de ganancia automática (AGC). Se utiliza una estimacion de energía de la senal de salida de AGC en cada una de las n muestras de las senales de difusion para calcular y actualizar un valor de control de ganancia. En lugar de utilizar todas las n muestras que se producen subsiguientemente a una actualizacion de un valor de control de ganancia anterior se utiliza solamente un subconjunto de esas muestras. En particular, se puede descartar solo la primera mitad de las muestras en el cálculo de estimacion de energía, a la vez que solo se puede utilizar la segunda mitad de las n muestras.

    ADQUISICION DE TEMPORIZACION PRECISA
    13.
    发明专利
    ADQUISICION DE TEMPORIZACION PRECISA 未知

    公开(公告)号：AR055745A1

    公开(公告)日：2007-09-05

    申请号：ARP060100934

    申请日：2006-03-10

    Applicant: QUALCOMM INC

    Inventor： VRCELJ BOJAN ,  LING FUYUN ,  KRISHNAMOORTHI RAGHURAMAN ,  MURTHY VINAY

    IPC: H04L27/26

    Abstract: Un método para sincronizar la temporizacion de un receptor de senal multiplexada por division ortogonal de la frecuencia (OFDM). Se ejecuta una primera adquisicion de la temporizacion con un primer piloto multiplexado por division de tiempo (TDM) recibido para determinar una estimacion de temporizacion aproximada de la senal OFDM recibida. Se ejecuta una segunda adquisicion de temporizacion con un segundo piloto TDM para determinar una estimacion de temporizacion precisa de un símbolo OFDM de la senal OFDM recibida. En la segunda adquisicion de temporizacion, la energía acumulada de la derivacion de canal en una ventana de deteccion es determinada y se detecta un borde de rastreo de la curva de energía acumulada. Una ubicacion de ventana de coleccion de la transformada de Fourier (FT) para símbolos subsiguientes de OFDM es ajustada para los símbolos en OFDM subsiguiente de acuerdo con la informacion del borde de rastreo.

    AUTOMATIC FREQUENCY CONTROL FOR A WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE SUBCARRIERS
    14.
    发明专利
    AUTOMATIC FREQUENCY CONTROL FOR A WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE SUBCARRIERS 未知

    公开(公告)号：SG160381A1

    公开(公告)日：2010-04-29

    申请号：SG2010016178

    申请日：2006-03-13

    Applicant: QUALCOMM INC

    Inventor： MURTHY VINAY ,  GUPTA ALOK ,  CHUNG SEONG TAEK ,  LING FUYUN

    Abstract: Techniques for performing frequency control in an OFDM system are described. In one aspect, frequency acquisition is performed based on a received pilot, and frequency tracking is performed based on received OFDM symbols. For frequency acquisition, an initial frequency error estimate may be derived based on the received pilot, and an automatic frequency control (AFC) loop may be initialized with the initial frequency error estimate. For frequency tracking, a frequency error estimate may be derived for each received OFDM symbol, and the AFC loop may be updated with the frequency error estimate. Frequency error in input samples is corrected by the AFC loop with the initial frequency error estimate as well as the frequency error estimate for each received OFDM symbol. In another aspect, a variable number of samples of a received OFDM symbol are selected, e.g., based on the received OFDM symbol timing, for use for frequency error estimation.

    AUTOMATIC FREQUENCY CONTROL FOR A WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE SUBCARRIERS
    16.
    发明专利
    AUTOMATIC FREQUENCY CONTROL FOR A WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE SUBCARRIERS 未知

    公开(公告)号：CA2600489A1

    公开(公告)日：2006-09-21

    申请号：CA2600489

    申请日：2006-03-13

    Applicant: QUALCOMM INC

    Inventor： LING FUYUN ,  MURTHY VINAY ,  GUPTA ALOK ,  CHUNG SEONG TAEK

    IPC: H03J7/04

    Abstract: Techniques for performing frequency control in an OFDM system are described. In one aspect, frequency acquisition is performed based on a received pilot, and frequency tracking is performed based on received OFDM symbols. For frequency acquisition, an initial frequency error estimate may be derived based on the received pilot, and an automatic frequency control (AFC) loop may be initialized with the initial frequency error estimate. For frequency tracking, a frequency error estimate may be derived for each received OFDM symbol, and the AFC loop may be updated with the frequency error estimate. Frequency error in input samples is corrected by the AFC loop with the initial frequency error estimate as well as the frequency error estimate for each received OFDM symbol. In another aspect, a variable number of samples of a received OFDM symbol are selected, e.g., based on the received OFDM symbol timing, for use for frequency error estimation.

    PHASE COMPENSATION FOR ANALOG GAIN SWITCHING IN OFDM MODULATED PHYSICAL CHANNEL
    17.
    发明申请
    PHASE COMPENSATION FOR ANALOG GAIN SWITCHING IN OFDM MODULATED PHYSICAL CHANNEL 审中-公开
    在OFDM调制的物理通道中进行模拟增益切换的相位补偿

    公开(公告)号：WO2007117723A3

    公开(公告)日：2008-06-05

    申请号：PCT/US2007060189

    申请日：2007-01-05

    Applicant: QUALCOMM INC ,  MURTHY VINAY ,  LI LINBO ,  KRISHNAMOORTHI RAGHURAMAN

    Inventor： MURTHY VINAY ,  LI LINBO ,  KRISHNAMOORTHI RAGHURAMAN

    IPC: H03G1/00 ,  H04B17/40

    CPC classification number: H03G1/0088 ,  H03G3/3052 ,  H04L27/2657

    Abstract: A control of an amplifier in an automatic gain control (AGC) loop, e.g. in the RF front end circuitry of an OFDM receiver, provides phase adjustment control data to an associated automatic frequency control (AFC), to compensate for a phase jump that would otherwise be caused by switching of the AGC gain between discrete gain states. In the disclosed example, for each gain state, comparators detect a signal energy estimate crossing either a high threshold or a low threshold. Upon threshold crossing, multiplexers select compensation data corresponding to the necessary transition from the prior state to the new state determined by the comparators, based on identification of the prior state and on the particular threshold that has been crossed (high or low). The phase compensation data supplied to the AFC, for one interval corresponding to the timing of the gain switching, adjusts phase rotation implemented in the AFC.

    Abstract translation: 自动增益控制（AGC）回路中放大器的控制，例如。 在OFDM接收机的RF前端电路中，向相关联的自动频率控制（AFC）提供相位调整控制数据，以补偿否则将由离散增益状态之间的AGC增益切换引起的相位跳变。 在所公开的示例中，对于每个增益状态，比较器检测穿过高阈值或低阈值的信号能量估计。 在阈值交叉时，多路复用器基于先前状态的识别和已经被交叉（高或低）的特定阈值来选择对应于从比较器确定的从先前状态到新状态的必要转换的补偿数据。 提供给AFC的相位补偿数据在对应于增益切换的定时的一个间隔内调整在AFC中实现的相位旋转。

    AUTOMATIC GAIN CONTROL
    19.
    发明申请
    AUTOMATIC GAIN CONTROL 审中-公开
    自动增益控制

    公开(公告)号：WO2007115327A3

    公开(公告)日：2007-12-13

    申请号：PCT/US2007066000

    申请日：2007-04-04

    Applicant: QUALCOMM INC ,  KRISHNAMOORTHI RAGHURAMAN ,  MURTHY VINAY

    Inventor： KRISHNAMOORTHI RAGHURAMAN ,  MURTHY VINAY

    IPC: H03G3/00 ,  H03G3/30

    CPC classification number: H03G3/002 ,  H03G3/3089 ,  H03M1/185

    Abstract: Techniques for performing automatic gain control are described. In some aspects, the gain control is achieved with an apparatus having an analog-to-digital converter (ADC) and a digital variable gain amplifier (DVGA), the DVGA configured to receive a digital signal from the ADC, the DVGA having a processor configured to compute a gain using a base n logarithm based on the power of the digital signal output from the ADC, the processor being further configured to apply the gain to the digital signal.

    Abstract translation: 描述了执行自动增益控制的技术。 在一些方面，利用具有模数转换器（ADC）和数字可变增益放大器（DVGA）的装置来实现增益控制，DVGA被配置为从ADC接收数字信号，DVGA具有处理器 被配置为基于从ADC输出的数字信号的功率使用基本对数来计算增益，所述处理器还被配置为将所述增益应用于所述数字信号。

    AUTOMATIC GAIN CONTROL FOR A WIRELESS RECEIVER
    20.
    发明申请
    AUTOMATIC GAIN CONTROL FOR A WIRELESS RECEIVER 审中-公开
    无线接收机的自动增益控制

    公开(公告)号：WO2006099530A3

    公开(公告)日：2006-12-21

    申请号：PCT/US2006009473

    申请日：2006-03-13

    Applicant: QUALCOMM INC ,  MURTHY VINAY ,  KRISHNAMOORTHI RAGHURAMAN ,  LI LINBO

    Inventor： MURTHY VINAY ,  KRISHNAMOORTHI RAGHURAMAN ,  LI LINBO

    IPC: H03G3/30

    CPC classification number: H03G7/007 ,  H03G3/3068 ,  H03G3/3078 ,  H03G3/3089 ,  H04B1/18 ,  H04L27/2601 ,  H04L27/2614 ,  H04L27/2647

    Abstract: Techniques for performing automatic gain control (AGC) at a wireless receiver are described. The total gain for the wireless receiver is achieved with discrete gain steps for analog circuitry and continuous gain for a digital variable gain amplifier (DVGA). An AGC loop is updated based on power measurements for an output signal from the DVGA. A first gain for the analog circuitry is selected from among multiple discrete gain values based on the AGC loop to maintain the average power of a baseband signal within a predetermined range at an analog-to-digital converter (ADC) input. A second gain for the DVGA is selected based on the AGC loop to maintain the average power of the output signal at a reference power level. The first gain is switched in a manner to avoid saturation of the ADC caused by the baseband signal and to provide switching hysteresis. The AGC may be performed in log domain and with multiple modes.

    Abstract translation: 描述了在无线接收机处执行自动增益控制（AGC）的技术。 无线接收机的总增益通过模拟电路的离散增益步长和数字可变增益放大器（DVGA）的连续增益来实现。 基于来自DVGA的输出信号的功率测量来更新AGC环路。 基于AGC环路从多个离散增益值中选择模拟电路的第一增益，以将模拟 - 数字转换器（ADC）输入端的基带信号的平均功率维持在预定范围内。 基于AGC环路选择DVGA的第二增益，以将输出信号的平均功率维持在参考功率电平。 第一增益以避免由基带信号引起的ADC饱和并提供开关滞后的方式进行切换。 AGC可以在对数域和多种模式下执行。

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