公开(公告)号：JP2011066886A

公开(公告)日：2011-03-31

申请号：JP2010204812

申请日：2010-09-13

Applicant: Qualcomm Inc ,  クゥアルコム・インコーポレイテッドQualcomm Incorporated

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

IPC: H04J11/00 ,  H04J13/00

CPC classification number: H03J7/04 ,  H03J1/0083

Abstract: PROBLEM TO BE SOLVED: To provide a method for performing frequency control using dual-loop automatic frequency control (AFC). SOLUTION: A dual-loop AFC includes an inner loop that corrects short-term frequency variations due to the Doppler effect or the like, and an outer loop that corrects long-term frequency variations due to component tolerance and temperature variations. In one design, a first inner loop is performed for frequency control of a first system of a broadcast system or the like, a second inner loop is performed for frequency control of a second system of a cellular system or the like, and at least one outer loop is performed in order to adjust a reference frequency used to receive the first and second systems. Each inner loop estimates and corrects the frequency error in an input signal for associated system. Also, each inner loop may be made to be operable when receiving the system. The reference frequency may be used for frequency down conversion, sampling and/or other purposes. COPYRIGHT: (C)2011,JPO&INPIT

Abstract translation: 要解决的问题：提供一种使用双回路自动频率控制（AFC）进行频率控制的方法。 解决方案：双回路AFC包括内环，其校正由于多普勒效应等引起的短期频率变化，以及校正由于部件容差和温度变化引起的长期频率变化的外环。 在一种设计中，对广播系统等的第一系统进行频率控制的第一内部循环，对蜂窝系统等的第二系统进行频率控制的第二内部循环，以及至少一个 执行外部循环以便调整用于接收第一和第二系统的参考频率。 每个内循环估计并校正相关系统的输入信号中的频率误差。 此外，每个内循环可以在接收系统时可操作。 参考频率可用于降频转换，采样和/或其他目的。 版权所有（C）2011，JPO＆INPIT

公开(公告)号：AU2002346605B2

公开(公告)日：2008-09-11

申请号：AU2002346605

申请日：2002-11-27

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK

IPC: H03M13/25 ,  H03M13/39 ,  H04J11/00 ,  H04L1/00 ,  H04L25/03 ,  H04L25/06 ,  H04L27/14 ,  H04L27/26

Abstract: An apparatus and method for recovering data transmitted in a wireless communication system is claimed. A plurality of signal points, the signal point including a plurality of modulation symbols from a plurality of coded bits, is received. A first subset of signal points for which a bit is equal to a first value and a second subset of signal points for which the bit is equal to a second value is determined. The first and second subsets are signal points from an expanded signal constellation. The probability that the bit is equal to the first value or the second value is determined as a function of the received signal point. A soft decision symbol may then be determined, based on the probability that the bit is equal to the first value or the second value. The soft decision symbols may be represented as log likelihood ratios.

公开(公告)号：CA2497739A1

公开(公告)日：2004-04-08

申请号：CA2497739

申请日：2003-09-04

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK ,  VIJAYAN RAJIV

IPC: H04J11/00 ,  H04L25/02 ,  H04B1/69 ,  H04B7/10 ,  H04B1/76

Abstract: An improved channel estimation is disclosed. In one embodiment, initial channel estimation is performed using known training data sequence. The data packet received is demodulated based on the initial channel estimates, de- interleaved and decoded. The decoded data is then is re-encoded, interleaved and modulated to generate additional training symbols for updating the chann el estimates throughout the received data packet.

公开(公告)号：AR039071A1

公开(公告)日：2005-02-09

申请号：ARP020104624

申请日：2002-11-29

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK

IPC: H03M13/25 ,  H03M13/39 ,  H04J11/00 ,  H04L1/00 ,  H04L25/03 ,  H04L25/06 ,  H04L27/14 ,  H04L27/26 ,  H04B1/00

Abstract: Se reivindica un aparato y método para recuperar datos transmitidos en un sistema de comunicación inalámbrico. Una pluralidad de puntos de senal es recibida, el punto de senal comprende una pluralidad de símbolos de modulación a partir de una pluralidad de bits codificados. Se determina un primer subconjunto de puntos de senal para lo cual un bit es igual a un primer valor y un segundo subconjunto de puntos de senal para lo cual el bit es igual a un segundo valor. El primer y segundo subconjunto son puntos de senal de una constelación de senal expandida. La probabilidad de que el bit sea igual al primer valor o al segundo valor está determinada como una función del punto de senal recibido. Un símbolo de decisión blando puede entonces ser determinado, en base a la probabilidad de que el bit sea igual al primer valor o al segundo valor. Los símbolos de decisión blandos pueden estar representados como relaciones de probabilidad logarítmica.

公开(公告)号：BR0214528A

公开(公告)日：2004-12-28

申请号：BR0214528

申请日：2002-11-27

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK

IPC: H03M13/25 ,  H03M13/39 ,  H04J11/00 ,  H04L1/00 ,  H04L25/03 ,  H04L25/06 ,  H04L27/14 ,  H04L27/26

Abstract: An apparatus and method for recovering data transmitted in a wireless communication system is claimed. A plurality of signal points, the signal point including a plurality of modulation symbols from a plurality of coded bits, is received. A first subset of signal points for which a bit is equal to a first value and a second subset of signal points for which the bit is equal to a second value is determined. The first and second subsets are signal points from an expanded signal constellation. The probability that the bit is equal to the first value or the second value is determined as a function of the received signal point. A soft decision symbol may then be determined, based on the probability that the bit is equal to the first value or the second value. The soft decision symbols may be represented as log likelihood ratios.

公开(公告)号：CA2468574A1

公开(公告)日：2003-06-05

申请号：CA2468574

申请日：2002-11-27

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK

IPC: H03M13/25 ,  H03M13/39 ,  H04J11/00 ,  H04L1/00 ,  H04L25/03 ,  H04L25/06 ,  H04L27/14 ,  H04L27/26

Abstract: An apparatus and method for recovering data transmitted in a wireless communication system is claim. A plurality of signal points, the signal poin t comprising a plurality of modulation symbols from a plurality of coded bits, is received (604). A first subset of signal points for which a bit is equal to a first value and a second subset of signal points for which the bit is equa l to a second value is determined (608). The first and second subset are signa l points from an expanded signal constelation. The probability of that the bit is equal to the first value or the second value is determined as a function of the received signal point (612). A soft decision symbol may then be determined, based on the probability that the bit is equal to the first valu e or the second value. The soft decision symbols may be represented as log likelihood ratios (616).

公开(公告)号：RU2369016C2

公开(公告)日：2009-09-27

申请号：RU2006110539

申请日：2004-09-01

Applicant: QUALCOMM INC

Inventor： LIN FUJUN ,  GUPTA ALOK ,  KRISHNAMURTKHI RAGKHURAMAN ,  MURALI RAMASVAMI ,  VIDZHAJAN RADZHIV ,  VRSEL BOJAN

IPC: H04B3/10 ,  H04B7/005 ,  H04J20060101 ,  H04J1/16 ,  H04J11/00

Abstract: Изобретениеотноситсяк системампередачиданныхи, вчастности, ксинхронизациив беспроводнойшироковещательнойсистеме, использующеймультиплексированиес ортогональнымчастотнымразделениемканалов (МОЧРК). Техническимрезультатомявляетсяэффективноедостижениесинхронизации. Передатчикв беспроводнойшироковещательнойсистемес МОЧРКосуществляетшироковещательнуюпередачупервогопилот-сигналамультиплексированияс временнымразделением (МПВР) впервомнабореподдиапазонов, сопровождаемоговторымпилот-сигналомМПВРвовторомнабореподдиапазоновв каждомкадре. Поддиапазоныв каждомнаборевыбираютсяизчисла N суммарныхподдиапазоновтак, что (1) символМОЧРКдляпервогопилот-сигналаМПВРсодержитпоменьшеймере S1 идентичныхпоследовательностейпилот-сигнала-1 длиной L1 и (2) символМОЧРКдлявторогопилот-сигналаМПВРсодержитпоменьшеймере S2 идентичныхпоследовательностейпилот-сигнала-2 длиной L2. Передатчиктакжеможетосуществлятьшироковещательнуюпередачупилот-сигналаМПЧР. Приемникобрабатываетпервыйпилот-сигналМПВРдляполучениясогласованияповременикадрови дополнительнообрабатываетвторойпилот-сигналМПВРдляполучениясогласованияповременисимволов. 6 н. и 37 з.п. ф-лы, 11 ил.

公开(公告)号：ZA200404175B

公开(公告)日：2005-08-11

申请号：ZA200404175

申请日：2004-05-27

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK

IPC: H03M13/25 ,  H03M13/39 ,  H04J11/00 ,  H04L1/00 ,  H04L25/03 ,  H04L25/06 ,  H04L27/14 ,  H04L27/26 ,  H04L

Abstract: An apparatus and method for recovering data transmitted in a wireless communication system is claimed. A plurality of signal points, the signal point including a plurality of modulation symbols from a plurality of coded bits, is received. A first subset of signal points for which a bit is equal to a first value and a second subset of signal points for which the bit is equal to a second value is determined. The first and second subsets are signal points from an expanded signal constellation. The probability that the bit is equal to the first value or the second value is determined as a function of the received signal point. A soft decision symbol may then be determined, based on the probability that the bit is equal to the first value or the second value. The soft decision symbols may be represented as log likelihood ratios.

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.

公开(公告)号：BRPI0413985A

公开(公告)日：2006-11-14

申请号：BRPI0413985

申请日：2004-09-01

Applicant: QUALCOMM INC

Inventor： LING FUNYUN ,  GUPTA ALOK ,  KRISHNAMOORTHI RAGHURAMAN ,  MURALI RAMASWAMY ,  VIJAYAN RAJIV

IPC: H04B3/10 ,  H04J20060101 ,  H04J1/16 ,  H04J11/00

Abstract: In an OFDM system, a transmitter broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least S1 identical pilot-1 sequences of length L1 and (2) an OFDM symbol for the second TDM pilot contains at least S2 identical pilot-2 sequences of length L2, where L2>L1, S1.L1=N, and S2.L2=N. The transmitter may also broadcast an FDM pilot. A receiver processes the first TDM pilot to obtain frame timing (e.g., by performing correlation between different pilot-1 sequences) and further processes the second TDM pilot to obtain symbol timing (e.g., by detecting for the start of a channel impulse response estimate derived from the second TDM pilot).