公开(公告)号：WO2007035550A1

公开(公告)日：2007-03-29

申请号：PCT/US2006/036137

申请日：2006-09-15

Applicant: QUALCOMM INCORPORATED ,  SUBRAHMANYA, Parvathanathan ,  KANG, Inyup ,  FEI, Jia ,  SUNDARESAN, Rajesh

Inventor： SUBRAHMANYA, Parvathanathan ,  KANG, Inyup ,  FEI, Jia ,  SUNDARESAN, Rajesh

IPC: H04B1/707 ,  H04B7/08 ,  H04L25/03

CPC classification number: H04B1/71057 ,  H04B7/0669 ,  H04B7/0673 ,  H04B7/0845 ,  H04L25/03044 ,  H04L25/03292 ,  H04L2025/03509

Abstract: This disclosure describes equalization techniques for spread spectrum wireless communication. The techniques may involve estimating a channel impulse response, estimating channel variance, and selecting filter coefficients for an equalizer based on the estimated channel impulse response and the estimated channel variance. Moreover, in accordance with this disclosure, the channel variance estimation involves estimation of two or more co-variances for different received samples. Importantly, the equalizer is "fractionally spaced" which means that the equalizer defines fractional filtering coefficients (filter taps), unlike conventional equalizers that presume that filter coefficients are defined at integer chip spacing. The techniques can allow the equalizer to account for antenna diversity, such as receive diversity, transmit diversity, or possibly both.

Abstract translation: 本公开描述了用于扩频无线通信的均衡技术。 这些技术可以包括基于所估计的信道脉冲响应和所估计的信道方差估计信道脉冲响应，估计信道方差，以及为均衡器选择滤波器系数。 此外，根据本公开，信道方差估计涉及对于不同接收样本的两个或多个协方差的估计。 重要的是，均衡器是“分数间隔”的，这意味着均衡器定义分数滤波系数（滤波器抽头），不同于传统的均衡器，假设滤波器系数是以整数芯片间隔定义的。 这些技术可以允许均衡器考虑天线分集，例如接收分集，发射分集，或者可能两者。

公开(公告)号：WO2007059517A3

公开(公告)日：2007-05-24

申请号：PCT/US2006/060947

申请日：2006-11-15

Applicant: QUALCOMM INCORPORATED ,  MERGEN, Gokhan ,  SUBRAHMANYA, Parvathanathan ,  KASTURI, Nitin ,  SUNDARESAN, Rajesh

Inventor： MERGEN, Gokhan ,  SUBRAHMANYA, Parvathanathan ,  KASTURI, Nitin ,  SUNDARESAN, Rajesh

IPC: H04L25/03 ,  H04L7/04 ,  H04L7/033 ,  H04B7/06 ,  H04B7/08

Abstract: Techniques for performing equalization at a receiver are described. In an aspect, equalization is performed by sub-sampling an over-sampled input signal to obtain multiple sub-sampled signals. An over-sampled channel impulse response estimate is derived and sub-sampled to obtain multiple sub-sampled channel impulse response estimates. At least one set of equalizer coefficients is derived based on at least one sub-sampled channel impulse response estimate. At least one sub-sampled signal is filtered with the at least one set of equalizer coefficients to obtain at least one output signal. One sub-sampled signal (e.g., with largest energy) may be selected and equalized based on a set of equalizer coefficients derived from an associated sub-sampled channel impulse response estimate. Alternatively, the multiple sub-sampled signals may be equalized based on multiple sets of equalizer coefficients, which may be derived separately or jointly. The equalizer coefficients may be derived in the time domain or frequency domain.

公开(公告)号：WO2004054126A1

公开(公告)日：2004-06-24

申请号：PCT/US2003/039393

申请日：2003-12-09

Applicant: QUALCOMM INCORPORATED

Inventor： KINDRED, Daniel, R. ,  LEVIN, Jeffrey, A. ,  SUNDARESAN, Rajesh

IPC: H04B1/707

CPC classification number: H04B1/7117 ,  H04B2201/70707

Abstract: Techniques for performing finger merge protection (FMP) using polling. Whenever a command to adjust the timing of a designated finger is received, other fingers "on the same channel" (i.e., those for which merge protection is sought) are polled for permission to apply the command. The designated finger sets a poll request and provides other pertinent information to an FMP storage unit. Thereafter, each of the other fingers on the same channel determines whether or not applying the command would result in that finger merging with the designated finger. Merging may be detected if the difference between the timing (or offsets) of the two fingers is less than a specified offset spacing. Any finger on the same channel may disallow the command if merging is detected. The designated finger would then adjust its timing if the command is not disallowed by any of the fingers on the same channel.

Abstract translation: 使用轮询执行手指合并保护（FMP）的技术。 只要接收到调整指定手指的定时的指令，轮询“在同一频道上”的其他手指（即寻求合并保护的手指），以允许应用该命令。 指定的手指设置轮询请求，并向FMP存储单元提供其他相关信息。 此后，同一通道上的每个其他手指确定是否应用该命令将导致该手指与指定的手指合并。 如果两个手指的定时（或偏移量）之间的差小于指定的偏移距离，则可以检测到合并。 如果检测到合并，同一通道上的任何手指可能不允许该命令。 如果同一通道上的任何手指不允许该命令，指定的手指将调整其定时。

公开(公告)号：WO2003003586A3

公开(公告)日：2003-01-09

申请号：PCT/US2002/020345

申请日：2002-06-26

Applicant: QUALCOMM INCORPORATED

Inventor： SHIU, Da-shan ,  SUNDARESAN, Rajesh

IPC: H03M13/45

Abstract: Techniques to improve the performance of a Turbo decoder when scale information for the bits in a code segment to be decoded is not known. A number of hypotheses are formed for the code segment, with each hypothesis corresponding to a particular set of one or more values for a set of one or more parameters used for decoding the code segment. For the MAP decoding scheme, these parameters may be for the sequence of scaling factors used to scale the bits prior to decoding and/or a scale used to evaluate a (e.g., min*) function for the MAP decoding. The code segment is decoded based on the MAP decoding scheme and in accordance with each hypothesis. The quality of the decoded result for each hypothesis is determined based on one or more performance metrics. The decoded bits for the best hypothesis are provided as the Turbo decoder output.

公开(公告)号：WO2007106876A2

公开(公告)日：2007-09-20

申请号：PCT/US2007/064014

申请日：2007-03-14

Applicant: QUALCOMM INCORPORATED ,  SIDI, Jonathan ,  SUNDARESAN, Rajesh

Inventor： SIDI, Jonathan ,  SUNDARESAN, Rajesh

CPC classification number: H03M13/2957 ,  H03M13/256 ,  H03M13/258 ,  H03M13/6325 ,  H04L25/067 ,  H04L27/38

Abstract: Techniques for efficiently and accurately computing log-likelihood ratio (LLRs) for code bits are described. A set of code bits may be mapped to a modulation symbol in a signal constellation. Different code bits in the set may be associated with different LLR functions. A receiver obtains received symbols for a transmission sent via a communication channel. The receiver derives LLRs for code bits based on the received symbols and piecewise linear approximation of at least one LLR function. The piecewise linear approximation of each LLR function may comprise one or more linear functions for one or more ranges of input values. The receiver may select one of the linear functions for each code bit based on a corresponding received symbol component value. The receiver may then derive an LLR for each code bit based on the linear function selected for that first code bit.

Abstract translation: 描述了用于有效和准确地计算码位的对数似然比（LLR）的技术。 一组码位可以映射到信号星座中的调制符号。 集合中的不同码位可能与不同的LLR功能相关联。 接收机获得经由通信信道发送的传输的接收符号。 接收机基于所接收的符号和至少一个LLR功能的分段线性近似，导出用于码位的LLR。 每个LLR函数的分段线性近似可以包括用于一个或多个输入值范围的一个或多个线性函数。 接收机可以基于相应的接收到的符号分量值为每个码位选择一个线性函数。 然后，接收机可以基于为该第一码位选择的线性函数导出每个码位的LLR。

公开(公告)号：WO2002060139A2

公开(公告)日：2002-08-01

申请号：PCT/US2002/002141

申请日：2002-01-23

Applicant: QUALCOMM INCORPORATED

Inventor： SENDONARIS, Andrew ,  SUNDARESAN, Rajesh

IPC: H04L25/02

CPC classification number: H04L25/0236

Abstract: Techniques for incorporating non-pilot symbols along with pilot symbols to improve the estimate of the characteristics (e.g. amplitude and phase) of a communication link. A pilot filter weighs samples corresponding to pilot and non-pilot symbol by different sets of coefficients, which have values determined by and/or corresponding to the confidence in the detected sample. Samples corresponding to pilot symbols are typically associated with higher degree of confidence and are weighted more (e.g., with weights of 1.0). Samples corresponding to non-pilot symbols are typically associated with lower confidence and are weighted with values that may be variable and dependent on the degree of confidence in the samples (e.g., with weights ranging from 0.0 up to 1.0). The weights are updated based on a particular estimator such as a MAP (Maximum a Posteriori) estimator, a MLE (Maximum Likelihood Estimator), or some other estimator.

Abstract translation: 用于将非导频符号与导频符号一起并入以改进通信链路的特性（例如振幅和相位）的估计的技术。 导频滤波器通过不同的系数集来对与导频符号和非导频符号相对应的采样值，该系数具有由检测样本中的置信度确定的值和/或对应于其的值。 对应于导频符号的样本通常与更高的置信度相关联，并且被加权更多（例如，具有1.0的权重）。 对应于非导频符号的采样通常与较低的置信度相关联，并且可以是可变的并且取决于样本中的置信度（例如，权重范围从0.0到1.0）的值来加权。 基于诸如MAP（最大后验）估计器，MLE（最大似然估计器）或一些其它估计器的特定估计器来更新权重。