公开(公告)号：US20060002487A1

公开(公告)日：2006-01-05

申请号：US10990344

申请日：2004-11-16

Applicant: Kai Kriedte ,  Syed Mujtaba ,  Xiaowen Wang

Inventor： Kai Kriedte ,  Syed Mujtaba ,  Xiaowen Wang

IPC: H04L1/02

CPC classification number: H04L27/2613 ,  H04B7/0684 ,  H04L1/0046 ,  H04L1/0061

Abstract: 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.

Abstract translation: 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：US20090092038A1

公开(公告)日：2009-04-09

申请号：US11866812

申请日：2007-10-03

Applicant: Syed Mujtaba ,  Xiaowen Wang

Inventor： Syed Mujtaba ,  Xiaowen Wang

IPC: H04J11/00

CPC classification number: H04L27/2678 ,  H04L5/0007 ,  H04L27/2662

Abstract: 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.

Abstract translation: 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：US07809046B2

公开(公告)日：2010-10-05

申请号：US11866812

申请日：2007-10-03

Applicant: Syed Mujtaba ,  Xiaowen Wang

Inventor： Syed Mujtaba ,  Xiaowen Wang

IPC: H04L27/30

CPC classification number: H04L27/2678 ,  H04L5/0007 ,  H04L27/2662

Abstract: 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.

Abstract translation: 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

Applicant: Syed Mujtaba ,  Xiaowen Wang

Inventor： Syed Mujtaba ,  Xiaowen Wang

IPC: H04B7/216 ,  H04L5/12

CPC classification number: H04L1/0643 ,  H04L1/0606

Abstract: 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.

Abstract translation: 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

Applicant: Syed Mujtaba ,  Xiaowen Wang

Inventor： Syed Mujtaba ,  Xiaowen Wang

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

CPC classification number: H04B7/0667 ,  H04B7/0684

Abstract: 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.

Abstract translation: 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：US08139677B2

公开(公告)日：2012-03-20

申请号：US12296434

申请日：2008-04-30

Applicant: Syed Mujtaba ,  Xiaowen Wang

Inventor： Syed Mujtaba ,  Xiaowen Wang

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

CPC classification number: H04L1/0643 ,  H04L1/0606

Abstract: 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.

Abstract translation: 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

Applicant: Syed Mujtaba ,  Xiaowen Wang

Inventor： Syed Mujtaba ,  Xiaowen Wang

IPC: H04J11/00

CPC classification number: H04L25/0206 ,  H04B7/0613 ,  H04B7/12 ,  H04L5/0007 ,  H04L5/0048 ,  H04L27/2613 ,  H04L27/2628

Abstract: 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.

Abstract translation: 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：US20110044160A1

公开(公告)日：2011-02-24

申请号：US12915107

申请日：2010-10-29

Applicant: Syed Mujtaba

Inventor： Syed Mujtaba

IPC: H04J11/00

CPC classification number: H04L27/2628

Abstract: An exemplary fast Fourier transform (FFT) numerology for an orthogonal frequency division multiple access (OFDMA) downlink transmission system is described. The exemplary FFT numerology reduces the FFT sampling rate for a given transmission bandwidth, thereby increasing the battery life of a UE. The FFT numerology increases robustness against Doppler spread, phase noise, and frequency offset, enabling operation in channels with high delay spread, such as occurs in mountainous regions. The described numerology might provide the following without altering standard sub-frame duration: increased intercarrier spacing; reduced FFT sampling frequency across the transmission bandwidths; reduced FFT size across all transmission bandwidths; increased number of OFDM symbols per sub-frame; and/or increased cyclic prefix length choices.

Abstract translation: 描述了用于正交频分多址（OFDMA）下行链路传输系统的示例性快速傅里叶变换（FFT）命理学。 示例性FFT命令学降低了给定传输带宽的FFT采样率，从而增加了UE的电池寿命。 FFT数学增加了针对多普勒扩展，相位噪声和频率偏移的鲁棒性，使得能够在具有高延迟扩展的信道中进行操作，例如在山区发生。 所描述的命理学可以提供以下，而不改变标准子帧持续时间：增加的载波间隔; 降低FFT采样频率跨传输带宽; 减少所有传输带宽的FFT大小; 每个子帧增加OFDM符号数; 和/或增加的循环前缀长度选择。

公开(公告)号：US20060067415A1

公开(公告)日：2006-03-30

申请号：US11223757

申请日：2005-09-09

Applicant: Syed Mujtaba

Inventor： Syed Mujtaba

IPC: H04K1/10

CPC classification number: H04B7/0669 ,  H04B7/0684 ,  H04B7/10 ,  H04L5/023 ,  H04L27/2602 ,  H04W48/08 ,  H04W48/16 ,  H04W84/12

Abstract: Methods and apparatus are provided for increasing data throughput in a multiple antenna communication system using additional subcarriers. The multiple antenna communication system includes at least one legacy system employing an N1 point fast Fourier transform (FFT) within a bandwidth, BW1. Data is transmitted using an N2 point inverse FFT within the bandwidth, BW1, wherein N2 is greater than N1; and subcarriers associated with the N2 point inverse FFT are employed to transmit the data. Data can also be transmitted using an N2 point inverse FFT within a bandwidth, BW2, wherein N2 is greater than N1 and the bandwidth, BW2, is greater than the bandwidth, BW1; and subcarriers associated with the N2 point inverse FFT are employed to transmit the data, wherein the employed subcarriers includes one or more additional subcarriers at outer edges of the bandwidth, BW1, relative to the legacy system and one or more additional subcarriers near DC relative to the legacy system.

Abstract translation: 提供了用于增加使用附加子载波的多天线通信系统中的数据吞吐量的方法和装置。 多天线通信系统包括在带宽BW 1范围内采用N 1点快速傅里叶变换（FFT）的至少一个传统系统。 数据使用宽带BW 1中的N 2点反FFT进行发送，其中N 2大于N 1 < / SUB>; 并且采用与N＆lt; 2＆gt;点逆FFT相关联的子载波来传送数据。 数据也可以使用宽带2中的N 2点反FFT进行传输，其中N 2> N 2大于N < 1＆lt;＆gt;和带宽BW＆lt; 2＆gt;之间的带宽大于带宽BW＆lt; 1＆gt;; 并且采用与N＆lt; 2＆gt;点逆FFT相关联的子载波来发送数据，其中所采用的子载波在带宽的外边缘包括一个或多个附加的子载波，BW＆lt; 1＆ ，相对于遗留系统和相对于遗留系统的DC附近的一个或多个附加子载波。

公开(公告)号：US20070224947A1

公开(公告)日：2007-09-27

申请号：US11388330

申请日：2006-03-24

Applicant: Edward Campbell ,  Syed Mujtaba

Inventor： Edward Campbell ,  Syed Mujtaba

IPC: H04B1/02 ,  H04M1/00

CPC classification number: H04B7/0684 ,  H04B7/04 ,  H04B7/0615 ,  H04B7/08 ,  H04L25/0204 ,  H04L25/0224 ,  H04L27/261

Abstract: Methods and apparatus are provided for per-antenna training in a multiple antenna communication system having a plurality of transmit antenna branches. A long training sequence is transmitted on each of the transmit antenna branches such that only one of the transmit antenna branches is active at a given time. The active transmit antenna branch is configured in a transmit mode during the given time and one or more of the inactive transmit antenna branches are configured in a receive mode during the given time. The transmit and receive modes are configured, for example, by applying a control signal to one or more switches.

Abstract translation: 在具有多个发射天线分支的多天线通信系统中提供用于每天线训练的方法和装置。 在每个发射天线分支上发送长训练序列，使得在给定时间只有一个发射天线分支是活动的。 在给定时间期间，有源发射天线分支被配置为发射模式，并且在给定时间内将一个或多个非活动发射天线分支配置为接收模式。 发送和接收模式例如通过将控制信号施加到一个或多个开关来配置。