公开(公告)号：US20060209979A1

公开(公告)日：2006-09-21

申请号：US11261513

申请日：2005-10-31

申请人： Magnus Sandell ,  Darren McNamara ,  Steve Parker

发明人： Magnus Sandell ,  Darren McNamara ,  Steve Parker

IPC分类号： H04L1/02

CPC分类号： H04L27/2657 ,  H04L27/2675 ,  H04L2027/0032 ,  H04L2027/0065 ,  H04L2027/0075

摘要： The present invention relates to estimating and correcting for frequency offset errors in wireless receivers, and is particularly but not exclusively related to MIMO WLAN applications. The present invention provides an improved method of tracking receiver frequency offsets in a receiver for MIMO systems. These receiver based frequency offset components are caused by errors or inaccuracies in various receiver sub-systems such as phase lock loops or carrier frequency oscillator error, and sampling clock rate errors. The frequency offsets due to each of a number of receiver sub-systems are estimated by monitoring frequency offsets on a number of channels or subcarriers (such as OFDM pilot channels) on different frequencies. These channel frequency offsets are preferably estimated by detecting the phase rotation between adjacent pilot symbols on each respective channel. They are then weighted according to a quality parameter of the estimates, which corresponds to their accuracy. An example of a quality parameter is the effective SNR of the respective channels, or preferably the error variance of the phase rotation. In an embodiment the quality parameter is or is proportional to ∥Hx∥2. The weighted channel frequency offsets are then used to determine one or more receiver sub-system frequency offset components. For example a least squares line fit analysis can be performed.

摘要翻译： 本发明涉及估计和校正无线接收机中的频率偏移误差，并且特别地但并不排他地涉及MIMO WLAN应用。 本发明提供了一种在MIMO系统的接收机中跟踪接收机频率偏移的改进方法。 这些基于接收机的频率偏移分量由各种接收机子系统中的错误或不准确性引起，例如锁相环或载波频率振荡器错误以及采样时钟速率误差。 通过在不同频率上的多个信道或子载波（例如OFDM导频信道）上监视频率偏移来估计由多个接收机子系统中的每一个引起的频率偏移。 这些信道频率偏移优选地通过检测每个相应信道上的相邻导频符号之间的相位旋转来估计。 然后根据估计的质量参数对它们进行加权，这对应于它们的准确度。 质量参数的示例是相应通道的有效SNR，或优选地是相位旋转的误差方差。 在一个实施例中，质量参数为或等于∥Hx∥2。 加权的信道频率偏移然后用于确定一个或多个接收机子系统频率偏移分量。 例如，可以执行最小二乘线拟合分析。

公开(公告)号：US06539067B1

公开(公告)日：2003-03-25

申请号：US09300495

申请日：1999-04-28

申请人： Carlo Luschi ,  Syed Aon Mujtaba ,  Magnus Sandell ,  Paul Edward Strauch ,  Ran-Hong Yan ,  Stephan ten Brink

发明人： Carlo Luschi ,  Syed Aon Mujtaba ,  Magnus Sandell ,  Paul Edward Strauch ,  Ran-Hong Yan ,  Stephan ten Brink

IPC分类号： H04L2706

CPC分类号： H04L25/0202

摘要： A method of estimating channel impulse response in a signal transmitted over a channel in a communication system is described. The channel estimator obtains a priori knowledge about the transmitted signal, and then uses the transmitted signal and the a priori knowledge to choose an estimate of channel impulse response which minimizes the expected distance between the transmitted signal and a reconstructed signal. The expected distance that is minimized is a cost function, represented by E{∥r−Bh∥2r}. By using soft decision feedback, the invention minimizes erroneous decision feedback which can cause error propagation. The decisions are usually in the form of log likelihood ratios (LLR).

摘要翻译： 描述了在通信系统中通过信道发送的信号中估计信道脉冲响应的方法。 信道估计器获得关于发射信号的先验知识，然后使用发射信号和先验知识来选择信道脉冲响应的估计，其使发射信号和重构信号之间的预期距离最小化。 最小化的预期距离是由E {‖r-Bh‖2r}表示的成本函数。 通过使用软判决反馈，本发明使可能导致错误传播的错误判定反馈最小化。 决策通常是对数似然比（LLR）的形式。

公开(公告)号：US06271772B1

公开(公告)日：2001-08-07

申请号：US09235049

申请日：1999-01-21

申请人： Carlo Luschi ,  Syed Aon Mujtaba ,  Magnus Sandell ,  Paul Edward Strauch ,  Ran-Hong Yan ,  Stephan ten Brink

发明人： Carlo Luschi ,  Syed Aon Mujtaba ,  Magnus Sandell ,  Paul Edward Strauch ,  Ran-Hong Yan ,  Stephan ten Brink

IPC分类号： H03M734

CPC分类号： H03M13/2948 ,  H03M13/29

摘要： Apparatus and method for iteratively decoding a signal are provided. The apparatus includes a central pool of resources for iteratively decoding signals. The central pool may run a plurality of iterative decoding processes, each process being allocated to a signal processing unit upon request and depending upon resource availability.

摘要翻译： 提供了用于迭代地解码信号的装置和方法。 该装置包括用于迭代地解码信号的中央资源库。 中央池可以运行多个迭代解码过程，每个进程根据请求分配给信号处理单元，并且取决于资源可用性。

公开(公告)号：US20080019262A1

公开(公告)日：2008-01-24

申请号：US11757057

申请日：2007-06-01

申请人： Andrew Lillie ,  Darren McNamara ,  Magnus Sandell

发明人： Andrew Lillie ,  Darren McNamara ,  Magnus Sandell

IPC分类号： H04J11/00

CPC分类号： H04L25/0246 ,  H04L27/2647

摘要： This invention relates to methods, apparatus, and processor control code for signal detection in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexed (MIMO-OFDM) communications systems. A method for determining outputs from a received signal in a lattice-reduction-aided receiver based multi-carrier wireless communications system having a plurality of sub-carriers divided into a plurality of sets of sub-carriers, the method comprising performing a detection method for each of said sets, the detection method comprising the step of applying lattice reduction to said set of sub-carriers thereby generating a reduced basis channel response.

摘要翻译： 本发明涉及用于多输入多输出正交频分复用（MIMO-OFDM）通信系统中的信号检测的方法，装置和处理器控制码。 一种用于在具有被划分成多组副载波的多个子载波的基于格子约简的辅助接收机的多载波无线通信系统中确定来自接收信号的输出的方法，所述方法包括执行检测方法 每个所述集合，所述检测方法包括对所述子载波集合应用网格约简的步骤，从而生成减少的基本信道响应。

公开(公告)号：US20060171483A1

公开(公告)日：2006-08-03

申请号：US11257012

申请日：2005-10-25

申请人： Yugang Jia ,  Christophe Andrieu ,  Magnus Sandell ,  Robert Piechocki

发明人： Yugang Jia ,  Christophe Andrieu ,  Magnus Sandell ,  Robert Piechocki

IPC分类号： H04L1/02

CPC分类号： H04L1/005 ,  H04L1/0071 ,  H04L1/0618 ,  H04L27/2608

摘要： Information is decoded from a signal received from a transmission over a MIMO channel from a plurality of transmit antennas, by means of a decoder and a corresponding decoding method. The signal is received on a plurality of receive antennas, and the information is encoded as a string of symbols over space and time and/or frequency. Each transmitted symbol has one of a plurality of values The decoding method comprises the steps of identifying a predetermined number of sets of symbol values, the sets being the most likely combinations of symbol values to be presented at the transmit antennas at a given time instant, and, for each symbol permitted for transmission, determining and outputting the probability of received information corresponding to the transmission of the symbol at a given antenna, on the basis of the other transmit antennas transmitting the symbol values of one of the identified sets. The latter step comprises determining the probability of a given symbol being transmitted at a given transmit antenna, given that the other transmit antennas are transmitting in accordance with one of the selected combinations identified as the most likely combinations. This is performed for all selected combinations, and the resultant probabilities are added together.

摘要翻译： 通过解码器和相应的解码方法，从多个发射天线的MIMO信道的传输接收的信号中解码信息。 该信号在多个接收天线上被接收，并且该信息被编码成空格，时间和/或频率上的一串符号。 每个发送的符号具有多个值中的一个。解码方法包括以下步骤：识别预定数量的符号值集合，这些集合是在给定时刻在发送天线处呈现的符号值的最可能组合， 并且对于允许发送的每个符号，基于发送所识别的集合中的一个的符号值的其他发送天线，确定并输出与给定天线处的符号的发送相对应的接收信息的概率。 后一步骤包括确定给定符号在给定发射天线处被发射的概率，假定其他发射天线根据被识别为最可能的组合的选定组合中的一个发射。 对所有选定的组合执行此操作，并将合成的概率相加。

公开(公告)号：US20050163245A1

公开(公告)日：2005-07-28

申请号：US11016812

申请日：2004-12-21

申请人： Magnus Sandell

发明人： Magnus Sandell

IPC分类号： H04J99/00 ,  H04B7/06 ,  H04B7/08 ,  H04J13/00 ,  H04L1/06 ,  H04L1/02

CPC分类号： H04B7/0891 ,  H04B7/06 ,  H04L1/0618

摘要： A channel scrambler for use in a transmitter employing a plurality of transmit antennas comprises at least two signal inputs for inputting a signal and a processor for applying a time-varying scrambling matrix to each input signal to produce a scrambled signal. An output stage is provided for outputting each scrambled signal to an antenna. The scrambling matrix is preferably different for each symbol period of a channel block.

摘要翻译： 在采用多个发射天线的发射机中使用的信道加扰器包括用于输入信号的至少两个信号输入和用于向每个输入信号施加时变加扰矩阵以产生加扰信号的处理器。 输出级用于将每个加扰信号输出到天线。 扰频矩阵优选地对于信道块的每个符号周期是不同的。

公开(公告)号：US20050089112A1

公开(公告)日：2005-04-28

申请号：US10935189

申请日：2004-09-08

申请人： Robert Piechocki ,  Magnus Sandell ,  Steve Parker ,  Christophe Andrieu

发明人： Robert Piechocki ,  Magnus Sandell ,  Steve Parker ,  Christophe Andrieu

IPC分类号： H04J99/00 ,  H04B7/06 ,  H04L1/00 ,  H04L1/06 ,  H04L25/03 ,  H04L1/02

CPC分类号： H04L1/005 ,  H04L1/0618 ,  H04L25/03171 ,  H04L2025/03375

摘要： This invention is generally concerned with methods, apparatus and processor control code for decoding a signal received over a MIMO (multiple input-multiple output) channel. A method of decoding a signal encoded as a string of symbols over space and time and/or frequency, transmitted over a MIMO (multiple-input multiple-output) channel, and received at a plurality of receive antennas, each transmitted symbol having one of a plurality of values, said decoding comprising determining a probability distribution for each symbol of the transmitted string of symbols; the method comprising: determining an initial estimate of said transmitted string of symbols from said received signal using an estimate of a response of said MIMO channel; and determining from said initial estimate a probability distribution for each symbol of the transmitted string of symbols, the probability distribution representing the likelihood of a symbol of the string having each of its possible values when other symbols of the transmitted string are treated as noise.

摘要翻译： 本发明通常涉及用于对通过MIMO（多输入多输出）信道接收的信号进行解码的方法，装置和处理器控制码。 一种通过空间和时间和/或频率编码为符号串的信号的方法，其通过MIMO（多输入多输出）信道发送并在多个接收天线处接收，每个发射符号具有 多个值，所述解码包括确定所发送的符号串的每个符号的概率分布; 所述方法包括：使用所述MIMO信道的响应的估计来从所述接收信号确定所述发送的符号串的初始估计; 并且从所述初始估计中确定所发送的符号串的每个符号的概率分布，所述概率分布表示当发送的字符串的其他符号被视为噪声时具有其每个可能值的字符串的符号的似然性。