公开(公告)号：US07809046B2

公开(公告)日：2010-10-05

申请号：US11866812

申请日：2007-10-03

申请人： Syed Mujtaba ,  Xiaowen Wang

发明人： Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04L27/30

CPC分类号： H04L27/2678 ,  H04L5/0007 ,  H04L27/2662

摘要： In one embodiment, a timing-offset estimator calculates a correlation value for each sample of an OFDM signal having a cyclic prefix for each OFDM symbol. The correlation value is provided to a tapped delay line that applies a separate weight to each of 2V correlation values, where V is the length of the cyclic prefix and the weights are based on a triangular weighting scheme that increases linearly from the first value, peaks at the Vth value, and decreases linearly to the 2Vth value. A stream of combined, squared correlation values is generated by combining and squaring the 2V weighted correlation values for each sample of the OFDM signal. For each cyclic prefix of the OFDM signal, a timing-offset estimate is determined based on a detected peak value in the stream of combined, squared correlation values. A timing-offset estimator with triangular weighting scheme may be implemented using recursive processing.

摘要翻译： 在一个实施例中，定时偏移估计器针对每个OFDM符号具有循环前缀的OFDM信号的每个样本计算相关值。 将相关值提供给一个抽头延迟线，该延迟线对2V相关值中的每一个施加单独的加权，其中V是循环前缀的长度，权重基于从第一个值线性增加的三角加权方案，峰值 在Vth值处，并且线性地减小到第2Vth值。 通过组合和平方OFDM信号的每个样本的2V加权相关值来产生组合的平方相关值的流。 对于OFDM信号的每个循环前缀，基于组合的平方相关值的流中的检测到的峰值来确定定时偏移估计。 具有三角加权方案的定时偏移估计器可以使用递归处理来实现。

公开(公告)号：US20100208716A1

公开(公告)日：2010-08-19

申请号：US12296434

申请日：2008-04-30

申请人： Syed Mujtaba ,  Xiaowen Wang

发明人： Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04B7/216 ,  H04L5/12

CPC分类号： H04L1/0643 ,  H04L1/0606

摘要： In one embodiment, the present invention generates a single rotation angle that may be used to maximize diversity of a quasi-orthogonal space-time block code that encodes groups of four data symbols. Two rotation angles corresponding the first two data symbols in a group are set to zero, and two rotation angles corresponding to the second two data symbols in a group are set to a single initial value. A codeword distance matrix is determined for each possible combination of codewords and erroneously decoded codewords that may be generated using the initial rotation angle, and the minimum of the determinants of these matrices is selected. This process is repeated to generate a plurality of minimum determinants, and, for each iteration, a different single rotation angle corresponding to the second two data symbols is used. Then, a single rotation angle is selected that corresponds to the maximum of the minimum determinants.

摘要翻译： 在一个实施例中，本发明产生单个旋转角度，其可用于最大化对四个数据符号组进行编码的准正交空时块代码的分集。 对应于组中的前两个数据符号的两个旋转角度被设置为零，并且与组中的第二两个数据符号相对应的两个旋转角度被设置为单个初始值。 针对可能使用初始旋转角度生成的码字和错误解码的码字的每个可能组合来确定码字距离矩阵，并且选择这些矩阵的最小值。 重复该过程以产生多个最小决定因素，并且对于每个迭代，使用与第二两个数据符号相对应的不同的单个旋转角度。 然后，选择对应于最小决定因素的最大值的单个旋转角度。

公开(公告)号：US20050276347A1

公开(公告)日：2005-12-15

申请号：US11043025

申请日：2005-01-24

申请人： Syed Mujtaba ,  Xiaowen Wang

发明人： Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04J99/00 ,  H04B7/06 ,  H04L27/26 ,  H04B7/02

CPC分类号： H04B7/0667 ,  H04B7/0684

摘要： Methods and apparatus are provided for communicating data in a multiple antenna communication system having N transmit antennas. According to one aspect of the invention, a header format includes a legacy preamble having at least one legacy long training field and an extended portion having at least N additional long training fields on each of the N transmit antennas. The N additional long training fields may be tone interleaved across the N transmit antennas and are used for MIMO channel estimation. The extended portion may include a short training field for power estimation. The short training field may be tone interleaved across the N transmit antennas and have an extended duration to support beam steering.

摘要翻译： 提供了用于在具有N个发射天线的多天线通信系统中传送数据的方法和装置。 根据本发明的一个方面，报头格式包括具有至少一个传统长训练场的传统前导码和在N个发射天线中的每一个上具有至少N个附加的长训练场的扩展部分。 N个附加的长训练场可以在N个发射天线之间进行音调交织，并用于MIMO信道估计。 扩展部分可以包括用于功率估计的短训练场。 短训练场可以在N个发射天线之间进行音调交织，并具有延长的持续时间以支持波束转向。

公开(公告)号：US20090092038A1

公开(公告)日：2009-04-09

申请号：US11866812

申请日：2007-10-03

申请人： Syed Mujtaba ,  Xiaowen Wang

发明人： Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04J11/00

CPC分类号： H04L27/2678 ,  H04L5/0007 ,  H04L27/2662

摘要： In one embodiment, a timing-offset estimator calculates a correlation value for each sample of an OFDM signal having a cyclic prefix for each OFDM symbol. The correlation value is provided to a tapped delay line that applies a separate weight to each of 2V correlation values, where V is the length of the cyclic prefix and the weights are based on a triangular weighting scheme that increases linearly from the first value, peaks at the Vth value, and decreases linearly to the 2Vth value. A stream of combined, squared correlation values is generated by combining and squaring the 2V weighted correlation values for each sample of the OFDM signal. For each cyclic prefix of the OFDM signal, a timing-offset estimate is determined based on a detected peak value in the stream of combined, squared correlation values. A timing-offset estimator with triangular weighting scheme may be implemented using recursive processing.

摘要翻译： 在一个实施例中，定时偏移估计器针对每个OFDM符号具有循环前缀的OFDM信号的每个样本计算相关值。 将相关值提供给一个抽头延迟线，该延迟线对2V相关值中的每一个施加单独的加权，其中V是循环前缀的长度，权重基于从第一个值线性增加的三角加权方案，峰值 在Vth值处，并且线性地减小到第2Vth值。 通过组合和平方OFDM信号的每个样本的2V加权相关值来产生组合的平方相关值的流。 对于OFDM信号的每个循环前缀，基于组合的平方相关值的流中的检测到的峰值来确定定时偏移估计。 具有三角加权方案的定时偏移估计器可以使用递归处理来实现。

公开(公告)号：US20060002487A1

公开(公告)日：2006-01-05

申请号：US10990344

申请日：2004-11-16

申请人： Kai Kriedte ,  Syed Mujtaba ,  Xiaowen Wang

发明人： Kai Kriedte ,  Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04L1/02

CPC分类号： H04L27/2613 ,  H04B7/0684 ,  H04L1/0046 ,  H04L1/0061

摘要： Methods and apparatus are disclosed for processing received data in a multiple input multiple output (MIMO) communication system. A multiple antenna receiver can distinguish a MIMO transmission from other transmissions based on the detection of a predefined symbol following a legacy portion of a preamble. A preamble comprises a legacy portion and an extended portion. The legacy portion is comprised of a first long preamble followed by a first signal field and may be processed by both multiple antenna receivers and legacy receivers. The extended portion comprises the predefined symbol following the first signal field from the legacy portion. If the predefined symbol is a second long preamble, a MIMO transmission is detected by performing a correlation on the preamble to detect the second long preamble. If the predefined symbol is a second long signal field, a MIMO transmission is detected by performing a cyclic redundancy check to detect the second long signal field.

摘要翻译： 公开了用于在多输入多输出（MIMO）通信系统中处理接收数据的方法和装置。 多天线接收机可以基于在前导码的遗留部分之后的预定符号的检测来区分MIMO传输与其他传输。 前导码包括遗留部分和扩展部分。 遗留部分由第一长前导跟随第一信号场组成，并且可以由多个天线接收机和传统接收机两者来处理。 扩展部分包括来自遗留部分的第一信号字段之后的预定符号。 如果预定义符号是第二长前导码，则通过对前导码执行相关性来检测MIMO传输以检测第二长前导码。 如果预定符号是第二长信号字段，则通过执行循环冗余校验来检测第二长信号字段来检测MIMO传输。

公开(公告)号：US08139677B2

公开(公告)日：2012-03-20

申请号：US12296434

申请日：2008-04-30

申请人： Syed Mujtaba ,  Xiaowen Wang

发明人： Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04L27/04 ,  H04L27/12 ,  H04L27/20

CPC分类号： H04L1/0643 ,  H04L1/0606

摘要： In one embodiment, the present invention generates a single rotation angle that may be used to maximize diversity of a quasi-orthogonal space-time block code that encodes groups of four data symbols. Two rotation angles corresponding the first two data symbols in a group are set to zero, and two rotation angles corresponding to the second two data symbols in a group are set to a single initial value. A codeword distance matrix is determined for each possible combination of codewords and erroneously decoded codewords that may be generated using the initial rotation angle, and the minimum of the determinants of these matrices is selected. This process is repeated to generate a plurality of minimum determinants, and, for each iteration, a different single rotation angle corresponding to the second two data symbols is used. Then, a single rotation angle is selected that corresponds to the maximum of the minimum determinants.

摘要翻译： 在一个实施例中，本发明产生单个旋转角度，其可用于最大化对四个数据符号组进行编码的准正交空时块代码的分集。 对应于组中的前两个数据符号的两个旋转角度被设置为零，并且与组中的第二两个数据符号相对应的两个旋转角度被设置为单个初始值。 针对可能使用初始旋转角度生成的码字和错误解码的码字的每个可能组合来确定码字距离矩阵，并且选择这些矩阵的最小值。 重复该过程以产生多个最小决定因素，并且对于每个迭代，使用与第二两个数据符号相对应的不同的单个旋转角度。 然后，选择对应于最小决定因素的最大值的单个旋转角度。

公开(公告)号：US20060250943A1

公开(公告)日：2006-11-09

申请号：US11122147

申请日：2005-05-04

申请人： Syed Mujtaba ,  Xiaowen Wang

发明人： Syed Mujtaba ,  Xiaowen Wang

IPC分类号： H04J11/00

CPC分类号： H04L25/0206 ,  H04B7/0613 ,  H04B7/12 ,  H04L5/0007 ,  H04L5/0048 ,  H04L27/2613 ,  H04L27/2628

摘要： Methods and apparatus are provided for improved efficiency in an extended multiple antenna communication system. A multiplier is employed on the number of points in the FFT that is greater than the multiplier on the frequency (bandwidth) of the legacy 802.11 a/g system. In one exemplary implementation, a 256 point FFT is employed in 40 MHz (with a 4N multiplier on the number of possible tones and a 2N multiplier on the frequency). While the efficiency for the OFDM symbol is improved, additional overhead is required in the preamble training (the length of the preamble is proportional to the number of tones in the FFT). Thus, a number of preamble constructs are provided that couple the improved efficiency with shorter preambles. In addition, an improved tone design provides additional efficiency gains.

摘要翻译： 提供了用于在扩展的多天线通信系统中提高效率的方法和装置。 FFT中的点数大于传统802.11 a / g系统的频率（带宽）乘数的乘数。 在一个示例性实现中，在40MHz中采用256点FFT（对于可能音调的数量具有4N乘法器，并且在频率上具有2N乘法器）。 虽然改进了OFDM符号的效率，但在前同步码训练中需要额外的开销（前导码的长度与FFT中的音调数成正比）。 因此，提供了许多前导码结构，其将改进的效率与较短的前导码相结合。 此外，改进的音调设计提供了额外的效率增益。

公开(公告)号：US10037206B2

公开(公告)日：2018-07-31

申请号：US13823355

申请日：2011-09-22

申请人： Xiaowen Wang

发明人： Xiaowen Wang

IPC分类号： H04L29/06 ,  G06F9/30 ,  G06F21/74

CPC分类号： G06F9/30043 ,  G06F21/74 ,  G06F2221/2105 ,  G06F2221/2145 ,  H04L63/1441

摘要： Disclosed are methods and systems for state switching. The method is applied to a first hardware system. The first hardware system is connected with a second hardware system. The first hardware system has a first operation state and a second operation state. The second hardware system includes a memory unit. The memory unit has a first access state and a second access state. The memory unit is in the first access state currently. The method includes: the first hardware system sends an access state switching instruction to the second hardware system when the first hardware system enters the second operation state from the first operation state, wherein, the access state switching instruction is adapted to switch the memory unit of the second hardware system from the first access state to the second access state. The application of the present invention can ensure the security of key data, avoid the access of key data by malicious software, reduce the implementation costs and has a higher extensibility.

公开(公告)号：US08619907B2

公开(公告)日：2013-12-31

申请号：US11043025

申请日：2005-01-24

申请人： Syed Aon Mujtaba ,  Xiaowen Wang

发明人： Syed Aon Mujtaba ,  Xiaowen Wang

IPC分类号： H04L27/00

CPC分类号： H04B7/0667 ,  H04B7/0684

摘要： Methods and apparatus are provided for communicating data in a multiple antenna communication system having N transmit antennas. According to one aspect of the invention, a header format includes a legacy preamble having at least one legacy long training field and an extended portion having at least N additional long training fields on each of the N transmit antennas. The N additional long training fields may be tone interleaved across the N transmit antennas and are used for MIMO channel estimation. The extended portion may include a short training field for power estimation. The short training field may be tone interleaved across the N transmit antennas and have an extended duration to support beam steering.

摘要翻译： 提供了用于在具有N个发射天线的多天线通信系统中传送数据的方法和装置。 根据本发明的一个方面，报头格式包括具有至少一个传统长训练场的传统前导码和在N个发射天线中的每一个上具有至少N个附加的长训练场的扩展部分。 N个附加的长训练场可以在N个发射天线之间进行音调交织，并用于MIMO信道估计。 扩展部分可以包括用于功率估计的短训练场。 短训练场可以在N个发射天线之间进行音调交织，并具有延长的持续时间以支持波束转向。

公开(公告)号：US20120282975A1

公开(公告)日：2012-11-08

申请号：US13099204

申请日：2011-05-02

申请人： Syed A. Mujtaba ,  Wen Zhao ,  Xiaowen Wang ,  Vinay Majjigi

发明人： Syed A. Mujtaba ,  Wen Zhao ,  Xiaowen Wang ,  Vinay Majjigi

IPC分类号： H04W88/06

CPC分类号： H04W76/27 ,  H04W24/00 ,  H04W48/18 ,  H04W68/00 ,  H04W88/06

摘要： Electronic devices may be provided that contain wireless communication circuitry. The wireless communication circuitry may include radio-frequency transceiver circuitry coupled to antennas. An electronic device may include a baseband processor and other storage and processing circuitry that implements protocol stacks for handling multiple radio access technologies. The storage and processing circuitry may use the transceiver circuitry to convey data using a first radio access technology while periodically interrupting the conveying of the data to monitor a paging channel using a second radio access technology. In performing the paging channel monitoring operations, the storage and processing circuitry may enforce a time limit that ensures that operations using the first radio access technology are not disrupted more than desired.

摘要翻译： 可以提供包含无线通信电路的电子设备。 无线通信电路可以包括耦合到天线的射频收发器电路。 电子设备可以包括基带处理器和实现用于处理多个无线电接入技术的协议栈的其他存储和处理电路。 存储和处理电路可以使用收发器电路使用第一无线电接入技术传送数据，同时周期性地中断数据的传送以使用第二无线电接入技术监视寻呼信道。 在执行寻呼信道监视操作时，存储和处理电路可以强制执行时间限制，确保使用第一无线电接入技术的操作不会超出所期望的中断。