公开(公告)号：US09148325B2

公开(公告)日：2015-09-29

申请号：US13900535

申请日：2013-05-23

申请人： Ridha Hamila ,  Ozgur Ozdemir ,  Naofal Al-Dhahir

发明人： Ridha Hamila ,  Ozgur Ozdemir ,  Naofal Al-Dhahir

IPC分类号： H04L27/00 ,  H04L27/26

CPC分类号： H04L27/2646 ,  H04B7/0617 ,  H04B7/0626 ,  H04B7/0854 ,  H04L25/03993 ,  H04L27/2647 ,  H04L27/3863

摘要： Disclosed are an system and method for compensation of I/Q imbalance in a beamforming OFDM system. The system comprises: a TX beamformer configured at a transmitter end of the beamforming OFDM system; a noise whitener configured at a receiver end of the beamforming OFDM system; and a RX MMSE configured at the receiver end of the beamforming OFDM system. At least one of the TX beamformer, the noise whitener and the RX MMSE receiver, or any combination thereof are capable of jointly processing a carrier and its image subcarrier to compensate the I/Q imbalance in the beamforming system.

摘要翻译： 公开了一种用于补偿波束形成OFDM系统中的I / Q不平衡的系统和方法。 该系统包括：配置在波束成形OFDM系统的发射机端的TX波束形成器; 配置在波束成形OFDM系统的接收端的噪声增白器; 以及配置在波束成形OFDM系统的接收机端的RX MMSE。 TX波束形成器，噪声增白器和RX MMSE接收器中的至少一个或其任何组合能够联合处理载波及其图像副载波以补偿波束成形系统中的I / Q不平衡。

公开(公告)号：US08942335B2

公开(公告)日：2015-01-27

申请号：US12777421

申请日：2010-05-11

申请人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

发明人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

IPC分类号： H04B7/02 ,  H04L1/02 ,  H04B7/08 ,  H04B7/06 ,  H04L1/06 ,  H04L25/02 ,  H04L25/03

CPC分类号： H04B7/0684 ,  H04B7/0669 ,  H04B7/0848 ,  H04B7/0851 ,  H04B7/0854 ,  H04B7/0882 ,  H04L1/0618 ,  H04L25/0204 ,  H04L25/03006

摘要： The burden of designing multiple training sequences for systems having multiple transmit antennas, is drastically reduced by employing a single sequence from which the necessary multiple sequences are developed. The single sequence is selected to create sequences that have an impulse-like autocorrelation function and zero cross correlations. A sequence of any desired length Nt can be realized for an arbitrary number of channel taps, L. The created sequences can be restricted to a standard constellation (that is used in transmitting information symbols) so that a common constellation mapper is used for both the information signals and the training sequence. In some applications a training sequence may be selected so that it is encoded with the same encoder that is used for encoding information symbols. Both block and trellis coding is possible in embodiments that employ this approach.

摘要翻译： 为具有多个发射天线的系统设计多个训练序列的负担通过采用从其开发必需的多个序列的单个序列而大大降低。 选择单个序列以创建具有脉冲状自相关函数和零交叉相关的序列。 可以对任意数量的信道抽头L实现任何期望长度Nt的序列。所创建的序列可以被限制为标准星座（用于发送信息符号），使得公共星座映射器被用于 信息信号和训练序列。 在一些应用中，可以选择训练序列，使得它用与编码信息符号相同的编码器进行编码。 在采用这种方法的实施例中，块和网格编码都是可能的。

公开(公告)号：US20100220803A1

公开(公告)日：2010-09-02

申请号：US12777421

申请日：2010-05-11

申请人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

发明人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

IPC分类号： H04B7/02

CPC分类号： H04B7/0684 ,  H04B7/0669 ,  H04B7/0848 ,  H04B7/0851 ,  H04B7/0854 ,  H04B7/0882 ,  H04L1/0618 ,  H04L25/0204 ,  H04L25/03006

摘要： The burden of designing multiple training sequences for systems having multiple transmit antennas, is drastically reduced by employing a single sequence from which the necessary multiple sequences are developed. The single sequence is selected to create sequences that have an impulse-like autocorrelation function and zero cross correlations. A sequence of any desired length Nt can be realized for an arbitrary number of channel taps, L. The created sequences can be restricted to a standard constellation (that is used in transmitting information symbols) so that a common constellation mapper is used for both the information signals and the training sequence. In some applications a training sequence may be selected so that it is encoded with the same encoder that is used for encoding information symbols. Both block and trellis coding is possible in embodiments that employ this approach.

摘要翻译： 为具有多个发射天线的系统设计多个训练序列的负担通过采用从其开发必需的多个序列的单个序列而大大降低。 选择单个序列以创建具有脉冲状自相关函数和零交叉相关的序列。 可以对任意数量的信道抽头L实现任何期望长度Nt的序列。所创建的序列可以被限制为标准星座（用于发送信息符号），使得公共星座映射器被用于 信息信号和训练序列。 在一些应用中，可以选择训练序列，使得它用与编码信息符号相同的编码器进行编码。 在采用这种方法的实施例中，块和网格编码都是可能的。

公开(公告)号：US07746945B2

公开(公告)日：2010-06-29

申请号：US11190403

申请日：2005-07-27

申请人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

发明人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

IPC分类号： H04B7/02 ,  H04L1/02

CPC分类号： H04B7/0684 ,  H04B7/0669 ,  H04B7/0848 ,  H04B7/0851 ,  H04B7/0854 ,  H04B7/0882 ,  H04L1/0618 ,  H04L25/0204 ,  H04L25/03006

摘要： The burden of designing multiple training sequences for systems having multiple transmit antennas, is drastically reduced by employing a single sequence from which the necessary multiple sequences are developed. The single sequence is selected to create sequences that have an impulse-like autocorrelation function and zero cross correlations. A sequence of any desired length Nt can be realized for an arbitrary number of channel taps, L. The created sequences can be restricted to a standard constellation (that is used in transmitting information symbols) so that a common constellation mapper is used for both the information signals and the training sequence. In some applications a a training sequence may be selected so that it is encoded with the same encoder that is used for encoding information symbols. Both block and trellis coding is possible in embodiments that employ this approach.

摘要翻译： 为具有多个发射天线的系统设计多个训练序列的负担通过采用从其开发必需的多个序列的单个序列而大大降低。 选择单个序列以创建具有脉冲状自相关函数和零交叉相关的序列。 可以对任意数量的信道抽头L实现任何期望长度Nt的序列。所创建的序列可以被限制为标准星座（用于发送信息符号），使得公共星座映射器被用于 信息信号和训练序列。 在一些应用中，可以选择训练序列，使得它用与用于对信息符号进行编码的相同编码器进行编码。 在采用这种方法的实施例中，块和网格编码都是可能的。

公开(公告)号：US07450656B1

公开(公告)日：2008-11-11

申请号：US11490973

申请日：2006-07-21

申请人： Naofal Al-Dhahir ,  Suhas N. Diggavi ,  Anastasios Stamoulis

发明人： Naofal Al-Dhahir ,  Suhas N. Diggavi ,  Anastasios Stamoulis

IPC分类号： H04B7/02 ,  H04L1/02

CPC分类号： H04L27/2647 ,  H04B7/0851 ,  H04L1/0618 ,  H04L5/0023 ,  H04L5/0048 ,  H04L25/0226 ,  H04L25/0232 ,  H04L25/0242 ,  H04L2025/03414 ,  H04L2025/03426

摘要： In an environment where a block transmission takes place via a frequency selective channel that is characterized by channel parameters that change with time in the course of the transmission of a block, an arrangement employs pilot signals to ascertain some of the parameters, and estimates the remaining parameters through an interpolation process. In some embodiments, channel coefficients estimates are improved by employing estimates from previous blocks. In an OFDM system, the pilot signals are advantageously selected to be in clusters that are equally spaced from each other in the time or the frequency domains. This approach applies to multiple antennae arrangements, as well as to single antenna arrangements, and to arrangements that do, or do not, use space-time coding.

摘要翻译： 在通过频率选择信道进行块传输的环境中，频率选择信道的特征在于在块的传输过程中随时间变化的信道参数，布置采用导频信号来确定一些参数，并且估计其余的 参数通过插值过程。 在一些实施例中，通过使用来自先前块的估计来改善信道系数估计。 在OFDM系统中，导频信号有利地选择为在时域或频域中彼此相等间隔的簇。 这种方法适用于多个天线布置以及单个天线布置，以及用于或不使用空时编码的布置。

公开(公告)号：US07173976B1

公开(公告)日：2007-02-06

申请号：US11231451

申请日：2005-09-21

申请人： Naofal Al-Dhahir

发明人： Naofal Al-Dhahir

IPC分类号： H04B7/02

CPC分类号： H04B7/0845

摘要： Space-time block coding is combined with single-carrier, minimum-mean-square-error, frequency-domain equalization for wireless communication through a medium characterized by multi-paths. The transmitter encodes incoming symbols into two or more streams that are transmitted over a corresponding number of transmitting antennas. The encoding employs modulo arithmetic. Decoding in the receiver proceeds by converting received signals to frequency domain, linearly combining the signals to separate contribution of the signals from the two or more transmitting antennas equalizing the separated signals, converting the equalized signals to time domain, and applying the converted signals to a decision circuit.

摘要翻译： 空时块编码与通过多路径特征的介质的无线通信的单载波，最小均方误差，频域均衡相结合。 发射机将输入符号编码为在相应数量的发射天线上传输的两个或更多个流。 编码采用模运算。 接收机的解码通过将接收到的信号转换为频域，线性地组合信号以分离来自两个或更多个发送天线的信号的贡献，均衡分离的信号，将均衡的信号转换为时域，并将转换的信号应用于 决策电路。

公开(公告)号：US07092450B1

公开(公告)日：2006-08-15

申请号：US10026148

申请日：2001-12-19

申请人： Naofal Al-Dhahir

发明人： Naofal Al-Dhahir

IPC分类号： H04B7/07

CPC分类号： H04B7/0845

摘要： Space-time block coding is combined with single-carrier, minimum-mean-square-error, frequency-domain equalization for wireless communication through a medium characterized by multi-paths. The transmitter encodes incoming symbols into two or more streams that are transmitted over a corresponding number of transmitting antennas. The encoding employs modulo arithmetic. Decoding in the receiver proceeds by converting received signals to frequency domain, linearly combining the signals to separate contribution of the signals from the two or more transmitting antennas equalizing the separated signals, converting the equalized signals to time domain, and applying the converted signals to a decision circuit.

公开(公告)号：US09008205B1

公开(公告)日：2015-04-14

申请号：US11227626

申请日：2005-09-15

申请人： Naofal Al-Dhahir

发明人： Naofal Al-Dhahir

IPC分类号： H04B7/08 ,  H04B1/58

CPC分类号： H04B1/58 ,  H04B7/0413

摘要： A multi-input, multi-output pre-filter improves operation of a multi-input receiver by shortening the effective memory of the channel with a set of FIR filters. The coefficients of these FIR filters can be fashioned to provide a variety of controls by the designer, for example, the value of the effective memory.

摘要翻译： 多输入多输出预滤波器通过一组FIR滤波器缩短信道的有效存储器来改善多输入接收机的操作。 这些FIR滤波器的系数可以被设计成为设计者提供各种控制，例如有效存储器的值。

公开(公告)号：US08223862B2

公开(公告)日：2012-07-17

申请号：US12588585

申请日：2009-10-20

申请人： Tareq Yousuf Al-Naffouri ,  Naofal Al-Dhahir ,  Muhammad Saqib Sohail

发明人： Tareq Yousuf Al-Naffouri ,  Naofal Al-Dhahir ,  Muhammad Saqib Sohail

IPC分类号： H04K1/10 ,  H04L27/28

CPC分类号： H04L27/2647 ,  H04L25/022 ,  H04L25/0248 ,  H04L25/03159 ,  H04L25/03821

摘要： The OFDM channel estimation and Inter-Carrier Interference (ICI) cancellation method uses a few pilots within Orthogonal Frequency Division Multiplexing (OFDM) systems in general, and mobile OFDM systems in particular. The frequency domain channel is estimated using an eigenvalue based model reduction technique with high accuracy. A Minimum Mean Square Error (MMSE) based Finite Impulse Response (FIR) equalizer is then used to obtain an ICI free estimate of the transmitted signal.

摘要翻译： OFDM信道估计和载波间干扰（ICI）消除方法通常在正交频分复用（OFDM）系统中使用几个导频，特别是移动OFDM系统。 使用基于特征值的模型降低技术来估计频域信道，其具有高精度。 然后使用基于最小均方误差（MMSE）的有限脉冲响应（FIR）均衡器来获得发射信号的无ICI估计。

公开(公告)号：US07668255B1

公开(公告)日：2010-02-23

申请号：US11488342

申请日：2006-07-18

申请人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

发明人： Naofal Al-Dhahir ,  Christine Fragouli ,  William Turin

IPC分类号： H04L27/00 ,  H04L27/28 ,  H04L27/06 ,  H04L7/10

CPC分类号： H04L1/0618 ,  H04L25/0204 ,  H04L25/0212 ,  H04L25/0224

摘要： A training sequence is created for space-time diversity arrangement, having any training sequence length, while limiting the training sequence to a standard constellation. Given a number of channel unknowns that need to be estimated, L, a training sequence can be creates that yields minimum means squared estimation error for lengths Nt=kNPRUS+L−1, for any positive integer k≦1, where NPRUS a selected perfect roots-of-unity sequence (PRUS) of length N. The training sequence is created by concatenating k of the length N perfect roots-of-unity sequences, followed by L−1 initial symbols of that same PRUS. Good training sequences can be created for lengths Nt that cannot be obtained through the above method by concatenating a requisite number of symbols found through an exhaustive search.

摘要翻译： 为具有任何训练序列长度的时空分集排列创建训练序列，同时将训练序列限制为标准星座。 给定需要估计的多个信道未知数L，可以创建训练序列，对于任何正整数k＆nlE，其长度Nt = kNPRUS + L-1产生最小均方估计误差;其中NPRUS选择完美 长度为N的根序列（PRUS）。通过连接长度为N的完美根序列序列的k，随后是相同PRUS的L-1个初始符号来创建训练序列。 可以通过连接通过穷举搜索找到的必需数量的符号，通过上述方法无法获得长度Nt的良好训练序列。