公开(公告)号：JP2011101384A

公开(公告)日：2011-05-19

申请号：JP2010270461

申请日：2010-12-03

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

Inventor： VIJAYAN RAJIV ,  GUPTA ALOK KUMAR ,  KRISHNAMOORTHI RAGHURAMAN

IPC: H04J11/00 ,  H04B1/16 ,  H04L27/26

CPC classification number: H04L27/2656 ,  H04L27/2657 ,  H04L27/2675

Abstract: PROBLEM TO BE SOLVED: To provide a means for performing frequency error estimation and frame synchronization of an OFDM receiver based on a metric that is indicative of pilot power.
SOLUTION: The metric is defined based on cross-correlation between two received symbols obtained in two OFDM symbol periods. For frequency error estimation, a metric value is computed for each of multiple hypothesized frequency errors. The hypothesized frequency error for the metric value with the largest magnitude is provided as the estimated frequency error. For frame synchronization, a correlation value is obtained for each OFDM symbol period by the correlation metric values obtained in the NC (e.g. most recent) OFDM symbol periods having the NC expected values. The expected values are computed in a manner consistent with the manner in which the metric values are computed. Peak detection is performed on the correlation values obtained for different OFDM symbols to determine frame synchronization.
COPYRIGHT: (C)2011,JPO&INPIT

Abstract translation: 要解决的问题：提供一种用于基于指示导频功率的度量来执行OFDM接收机的频率误差估计和帧同步的装置。 解决方案：基于在两个OFDM符号周期中获得的两个接收符号之间的互相关来定义度量。 对于频率误差估计，针对多个假设的频率误差中的每一个计算度量值。 提供具有最大幅度的度量值的假设频率误差作为估计的频率误差。 对于帧同步，通过在具有NC期望值的NC（例如最近的）OFDM符号周期中获得的相关度量值，为每个OFDM符号周期获得相关值。 以与计算度量值的方式一致的方式计算期望值。 对针对不同OFDM符号获得的相关值执行峰值检测以确定帧同步。 版权所有（C）2011，JPO＆INPIT

公开(公告)号：JP2011055519A

公开(公告)日：2011-03-17

申请号：JP2010224248

申请日：2010-10-01

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

Inventor： GUPTA ALOK KUMAR

IPC: H04J11/00 ,  H04L27/26

CPC classification number: H04L27/2656 ,  H04L27/2657 ,  H04L27/2662 ,  H04L27/2675

Abstract: PROBLEM TO BE SOLVED: To provide a robust initial frame detection and symbol synchronization acquisition system and methodology.
SOLUTION: In the system and method, a first pilot is employed in conjunction with three acquisition stages. In the first stage, an attempt is made to observe the leading edge of a correlation curve associated with the first pilot symbol. In the second stage, a determination is made as to whether a leading edge was detected in the first stage by attempting to observe a flat portion and/or trailing edge of the correlation curve. Furthermore, during this second stage, a frequency loop can be updated to compensate frequency offset. The third stage is used for observing the trailing edge of the curve if it was not already observed in the second stage. Upon detection and confirmation of receipt of the first pilot, a second pilot can subsequently be employed to acquire precise symbol timing.
COPYRIGHT: (C)2011,JPO&INPIT

Abstract translation: 要解决的问题：提供鲁棒的初始帧检测和符号同步采集系统和方法。 解决方案：在系统和方法中，第一个导频与三个采集阶段结合使用。 在第一阶段，尝试观察与第一导频符号相关联的相关曲线的前沿。 在第二阶段中，通过尝试观察相关曲线的平坦部分和/或后缘来确定在第一阶段中是否检测到前缘。 此外，在该第二阶段期间，可以更新频率环以补偿频率偏移。 如果在第二阶段尚未观察到，则第三阶段用于观察曲线的后缘。 在检测并确认接收到第一导频时，随后可以采用第二导频来获取精确的符号定时。 版权所有（C）2011，JPO＆INPIT

公开(公告)号：CA2554752C

公开(公告)日：2010-06-01

申请号：CA2554752

申请日：2005-01-28

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK KUMAR

IPC: H04L27/26 ,  H04L5/06 ,  H04L27/06

Abstract: A timing estimation system and methodology are provided. In particular, a first pilot is employed in conjunction with three acquisition stages. In the first stage, an attempt is made to observe the leading edge of the correlation curve associated with the first pilot symbol. In the second stage, a determination is made to confirm a leading edge was detected in the first stage by attempting to observe a trailing edge of the correlation curve. Furthermore, during this second stage, a frequency loop is updated to account for frequency offset. The third stage is for observing the trailing edge of the curve if it was not already observed in stage two. Upon detection of receipt of the first pilot, a second pilot can subsequently be employed to acquire fine symbol timing.

公开(公告)号：BRPI0409108A

公开(公告)日：2006-05-02

申请号：BRPI0409108

申请日：2004-04-06

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK KUMAR

IPC: H04L27/26

Abstract: Techniques are provided for tracking residual frequency error and phase noise in an OFDM system. At a receiver, each received OFDM symbol is transformed with an FFT to obtain received modulation symbols, which are serialized. A phase locked loop (PLL) operates on the serialized received modulation symbols and provides an independent phase correction value for each received modulation symbol. Each received modulation symbol is corrected with its own phase correction value to obtain a phase-corrected symbol. The phase error in each phase-corrected symbol is detected to obtain a phase error estimate for that phase-corrected symbol. The phase error estimate for each phase-corrected symbol is filtered (e.g., with a second-order loop filter) to obtain a frequency error estimate, which is accumulated to obtain a phase correction value for another received modulation symbol. The phase-corrected symbols are not correlated because independent phase correction values are used for the received modulation symbols.

公开(公告)号：CA2551988A1

公开(公告)日：2005-08-04

申请号：CA2551988

申请日：2005-01-07

Applicant: QUALCOMM INC

Inventor： KRISHNAMOORTHI RAGHURAMAN ,  VIJAYAN RAJIV ,  GUPTA ALOK KUMAR

IPC: H04L27/26

Abstract: Frequency error estimation and frame synchronization are performed at a receiver in an OFDM system based on a metric that is indicative of detected pilot power. The metric may be defined based on cross-correlation between tw o received symbols obtained in two OFDM symbol periods. For frequency error estimation, a metric value is computed for each of multiple hypothesized frequency errors. The hypothesized frequency error for the metric value with the largest magnitude is provided as the estimated frequency error. For fram e synchronization, a correlation value is obtained for each OFDM symbol period by correlating metric values obtained for NC (e.g., most recent) OFDM symbol periods with NC expected values. The expected values are computed in a manne r consistent with the manner in which the metric values are computed. Peak detection is performed on the correlation values obtained for different OFDM symbol periods to determine frame synchronization.

公开(公告)号：DE602006013995D1

公开(公告)日：2010-06-10

申请号：DE602006013995

申请日：2006-07-27

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  CHARI MURALI RAMASWAMY ,  VIJAYAN RAJIV ,  MANTRAVADI ASHOK ,  GUPTA ALOK KUMAR ,  MUKKAVILLI KRISHNA KIRAN ,  WANG MICHAEL MAO ,  VRCELJ BOJAN ,  COLLINS BRUCE

IPC: H04L12/56 ,  H04L27/26 ,  H04W88/02 ,  H04W92/10

Abstract: Systems and methods are provided for processing forward link only (FLO) messages. A device for processing forward link only (FLO) wireless messages comprises receiving a FLO message and processing the FLO message including a header, an 8-bit FLO information block field, a 7-bit FLO count, an RF channel identifier, a transmit mode indicator, an outer code rate, and a stream identifier.

公开(公告)号：UA88893C2

公开(公告)日：2009-12-10

申请号：UAA200608838

申请日：2005-01-07

Applicant: QUALCOMM INC

Inventor： VIDJAIAN RAJIV ,  GUPTA ALOK KUMAR ,  KRISHNAMURTHY RAGHURMAN

IPC: H04L27/26

Abstract: Оценкаотклонениячастотыи кадроваясинхронизациявыполняютсяв приемникев ОЧРК-системе, базируясьнаметрике, котораяуказываетнаобнаруженнуюмощностьпилотногосигнала. Метрикаможетопределятьсянаосновевзаимнойкорреляциимеждудвумяпринятымисимволами, полученнымив двухпериодахОЧРК-символа. Дляоценкиотклонениечастотывычисляетсязначениеметрикидлякаждогоизмногочисленныхпредсказуемыхотклоненийчастоты. Предсказуемоеотклонениечастотыдлязначенияметрикис наибольшейвеличинойпредусматриваетсякакоцененноеотклонениечастоты. Длякадровойсинхронизациизначениякорреляцииполуч

公开(公告)号：AU2009202005A1

公开(公告)日：2009-06-11

申请号：AU2009202005

申请日：2009-05-21

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK KUMAR

IPC: H04L27/26

Abstract: A robust initial frame detection and symbol synchronization system and methodology are provided. In particular, a first pilot is employed in conjunction with three acquisition stages. In the first stage, an attempt is made to observe the leading edge of the correlation curve associated with the first pilot symbol. In the second stage, a determination is made as to whether a leading edge was detected in the first stage by attempting to observe a flat portion and/or trailing edge of the correlation curve. Furthermore, during this second stage, a frequency loop can be updated to account for frequency offset. The third stage is for observing the trailing edge of the curve if it was not already observed in stage two. Upon detection and confirmation of receipt of the first pilot, a second pilot can subsequently be employed to acquire fine symbol timing.

公开(公告)号：AU2005207364A1

公开(公告)日：2005-08-04

申请号：AU2005207364

申请日：2005-01-07

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK KUMAR ,  KRISHNAMOORTHI RAGHURAMAN ,  VIJAYAN RAJIV

IPC: H04L27/26

Abstract: Frequency error estimation and frame synchronization are performed at a receiver in an OFDM system based on a metric that is indicative of detected pilot power. The metric may be defined based on cross-correlation between two received symbols obtained in two OFDM symbol periods. For frequency error estimation, a metric value is computed for each of multiple hypothesized frequency errors. The hypothesized frequency error for the metric value with the largest magnitude is provided as the estimated frequency error. For frame synchronization, a correlation value is obtained for each OFDM symbol period by correlating metric values obtained for NC (e.g., most recent) OFDM symbol periods with NC expected values. The expected values are computed in a manner consistent with the manner in which the metric values are computed. Peak detection is performed on the correlation values obtained for different OFDM symbol periods to determine frame synchronization.

公开(公告)号：CA2522209A1

公开(公告)日：2004-10-28

申请号：CA2522209

申请日：2004-04-06

Applicant: QUALCOMM INC

Inventor： GUPTA ALOK KUMAR

IPC: H04J11/00 ,  H04L27/152 ,  H04L27/26

Abstract: Techniques are provided for tracking residual frequency error and phase nois e in an OFDM system. At a receiver, each received OFDM symbol is transformed with an FFT to obtain received modulation symbols, which are serialized. A phase locked loop (PLL) operates on the serialized received modulation symbo ls and provides an independent phase correction value for each received modulation symbol. Each received modulation symbol is corrected with its own phase correction value to obtain a phase-corrected symbol. The phase error i n each phase-corrected symbol is detected to obtain a phase error estimate for that phase-corrected symbol. The phase error estimate for each phase-correct ed symbol is filtered (e.g., with a second-order loop filter) to obtain a frequency error estimate, which is accumulated to obtain a phase correction value for another received modulation symbol. The phase-corrected symbols ar e not correlated because independent phase correction values are used for the received modulation symbols.