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11. 发明授权

US06603427B2 System and method for forming a beam and creating nulls with an adaptive array antenna using antenna excision and orthogonal Eigen-weighting 失效
标题翻译：使用天线切除和正交特征加权，用自适应阵列天线形成波束并产生零点的系统和方法
公开(公告)号：US06603427B2
公开(公告)日：2003-08-05
申请号：US09892248
申请日：2001-06-27
申请人： Khiem V. Cai , Robert L. Hartman
发明人： Khiem V. Cai , Robert L. Hartman
IPC分类号： G01S316
CPC分类号： G01S3/42 , G01S3/043 , G01S3/38 , H01Q3/2611 , H04B7/0845
摘要： A system and method for forming a beam and creating nulls. The inventive method combines frequency domain suppression technology for narrow-band jammer rejection with orthogonal weighting using Eigen analysis for jammer nulling and signal beam-forming for an array antenna system. The inventive system is adapted for use with an adaptive array antenna having a plurality of radiating elements. The system includes a frequency domain suppressor connected to the array antenna and an orthogonal weighting subsystem connected to the frequency domain suppressor. In the illustrative implementation, signals received by each radiating elements are processed by an analog front-end and digitized. The frequency domain suppressor includes a Fast Fourier transformer (FFT) and a frequency domain suppressor for each element in the array. The frequency domain suppressor further includes a threshold evaluator which reads the signals output by the FFT's and provides threshold controls to the spectral suppressors. The orthogonal subsystem includes an adaptive weighting unit connected to the output of each of the spectral suppressors. The orthogonal weighting subsystem further includes an orthogonal weighting estimator for determining and optimal orthogonal Eigen-weighting to be applied to each of the adaptive weighting units. The outputs of each of the adaptive weighting processors are combined and inverse Fast Fourier transformed to provide one or more output beams and or one or more nulls in an efficient manner designed to leave the system with at least one degree of freedom for other functions.
摘要翻译：一种用于形成光束并创建零点的系统和方法。本发明的方法将用于窄带干扰抑制的频域抑制技术与使用用于阵列天线系统的干扰消零和信号波束成形的特征分析的正交加权相结合。本发明的系统适用于具有多个辐射元件的自适应阵列天线。该系统包括连接到阵列天线的频域抑制器和连接到频域抑制器的正交加权子系统。在说明性实现中，由每个辐射元件接收的信号由模拟前端处理并数字化。频域抑制器包括阵列中每个元件的快速傅里叶变换器（FFT）和频域抑制器。频域抑制器还包括阈值评估器，其读取由FFT输出的信号，并向频谱抑制器提供阈值控制。正交子系统包括连接到每个频谱抑制器的输出的自适应加权单元。正交加权子系统还包括正交加权估计器，用于确定和最佳正交特征加权以适用于每个自适应加权单元。每个自适应加权处理器的输出被组合并且被快速傅里叶逆变换，以提供一个或多个输出波束和/或一个或多个空值，以有效的方式被设计为使系统具有至少一个自由度用于其他功能。

12. 发明授权

US5995535A Rapid time and frequency acquistion of spread spectrum waveforms via ambiguity transform 失效
标题翻译：通过模糊度变换快速地对频谱波形进行采样
公开(公告)号：US5995535A
公开(公告)日：1999-11-30
申请号：US965251
申请日：1997-11-06
申请人： Khiem V. Cai , Steven R. Severance
发明人： Khiem V. Cai , Steven R. Severance
IPC分类号： H04L7/027 , H04L7/04 , H04L27/00 , H04B1/69
CPC分类号： H04L27/0014 , H04L7/027 , H04L7/043
摘要： The present invention is a method of synchronizing a digital receiver to a digital transmitter in both frequency and time using a novel ambiguity transformation. The ambiguity transform combines time correlation and spectrum synchronization into an integrated two-dimensional transform process. The ambiguity transform includes the steps of multiplying a reference sequence with a received signal to create a product signal, calculating the magnitude of the spectrum of the product signal, and determining the peak product signal. Through multiple iterations of the ambiguity transform, and time and frequency shifts, a digital receiver may be synchronized to a digital transmitter. The method of the present invention may be implemented using a digital signal processor (DSP).
摘要翻译：本发明是一种使用新颖的模糊度变换在频率和时间上将数字接收机同步到数字发射机的方法。模糊变换将时间相关和频谱同步结合到一个集成的二维变换过程中。模糊度变换包括以下步骤：将参考序列与接收信号相乘以产生乘积信号，计算乘积信号的频谱的幅度，以及确定峰值乘积信号。通过模糊度变换的多次迭代以及时间和频率偏移，数字接收机可以与数字发射机同步。本发明的方法可以使用数字信号处理器（DSP）来实现。

13. 发明授权

US07848451B2 Digital pre-distortion technique using nonlinear filters 有权
标题翻译：使用非线性滤波器的数字预失真技术
公开(公告)号：US07848451B2
公开(公告)日：2010-12-07
申请号：US12580618
申请日：2009-10-16
申请人： Khiem V. Cai , David B. Rutan , Matthew S. Gorder , Don C. Devendorf
发明人： Khiem V. Cai , David B. Rutan , Matthew S. Gorder , Don C. Devendorf
IPC分类号： H04K1/02
CPC分类号： H04L25/03885 , H03F1/3247 , H03F1/3276 , H04L25/49 , H04L27/2626 , H04L27/368
摘要： A system and method for stabilizing a coefficient set used by a digital predistortion (DPD) engine to apply pre-distortion to a transmit signal and cancel distortion generated by a distorting element or distorting system when transmitting the transmit signal, including obtaining an initial coefficient set; rotating the initial coefficient set to maintain a phase of fundamental components (w10(t), . . . , w1Q(t)) of the initial coefficient set as a constant value; averaging in the time domain the rotated coefficient set to obtain an averaged coefficient set; applying the averaged coefficient set to the DPD engine, the initial coefficient set expressed in a first equation [27]; computing the phase of the fundamental components of the initial coefficient set with a second equation [28]; and computing the rotated coefficient set with a third equation [29].
摘要翻译：一种用于稳定由数字预失真（DPD）引擎使用的系数集的系统和方法，用于在传输所述发射信号时将预失真应用于发射信号并消除由失真元件或失真系统产生的失真，包括获得初始系数组 ; 旋转初始系数集合以保持初始系数的基本分量（w10（t），...，w1Q（t））的相位为一个常数值; 在时域中平均旋转系数，以获得平均系数集; 将平均系数集合应用于DPD引擎，以第一等式[27]表示的初始系数集; 用第二个等式计算初始系数集的基本分量的相位[28]; 并用第三个方程计算旋转的系数集[29]。

14. 发明申请

US20100054364A1 DIGITAL PRE-DISTORTION TECHNIQUE USING NONLINEAR FILTERS 有权
标题翻译：使用非线性滤波器的数字预失真技术
公开(公告)号：US20100054364A1
公开(公告)日：2010-03-04
申请号：US12580618
申请日：2009-10-16
申请人： Khiem V. Cai , David B. Rutan , Matthew S. Gorder , Don C. Devendorf
发明人： Khiem V. Cai , David B. Rutan , Matthew S. Gorder , Don C. Devendorf
IPC分类号： H04L25/49
CPC分类号： H04L25/03885 , H03F1/3247 , H03F1/3276 , H04L25/49 , H04L27/2626 , H04L27/368
摘要： A system and method for stabilizing a coefficient set used by a digital predistortion (DPD) engine to apply pre-distortion to a transmit signal and cancel distortion generated by a distorting element or distorting system when transmitting the transmit signal, including obtaining an initial coefficient set; rotating the initial coefficient set to maintain a phase of fundamental components (w10(t), . . . , w1Q(t)) of the initial coefficient set as a constant value; averaging in the time domain the rotated coefficient set to obtain an averaged coefficient set; applying the averaged coefficient set to the DPD engine, the initial coefficient set expressed in a first equation [27]; computing the phase of the fundamental components of the initial coefficient set with a second equation [28]; and computing the rotated coefficient set with a third equation [29].
摘要翻译：一种用于稳定由数字预失真（DPD）引擎使用的系数集的系统和方法，用于在传输所述发射信号时将预失真应用于发射信号并消除由失真元件或失真系统产生的失真，包括获得初始系数组 ; 旋转初始系数集合以保持初始系数的基本分量（w10（t），...，w1Q（t））的相位为一个常数值; 在时域中平均旋转系数，以获得平均系数集; 将平均系数集合应用于DPD引擎，以第一等式[27]表示的初始系数集; 用第二个等式计算初始系数集的基本分量的相位[28]; 并用第三个方程计算旋转的系数集[29]。

15. 发明授权

US07606322B2 Digital pre-distortion technique using nonlinear filters 有权
标题翻译：使用非线性滤波器的数字预失真技术
公开(公告)号：US07606322B2
公开(公告)日：2009-10-20
申请号：US11150445
申请日：2005-06-09
申请人： Khiem V. Cai , David B. Rutan , Matthew S. Gorder , Don C. Devendorf
发明人： Khiem V. Cai , David B. Rutan , Matthew S. Gorder , Don C. Devendorf
IPC分类号： H04K1/02
CPC分类号： H04L25/03885 , H03F1/3247 , H03F1/3276 , H04L25/49 , H04L27/2626 , H04L27/368
摘要： A linearizer and method. In a most general embodiment, the inventive linearizer includes a characterizer coupled to an input to and an output from said circuit for generating a set of coefficients and a predistortion engine responsive to said coefficients for predistorting a signal input to said circuit such that said circuit generates a linearized output in response thereto. In a specific application, the circuit is a power amplifier into which a series of pulses are sent during an linearizer initialization mode of operation. In a specific implementation, the characterizer analyzes finite impulse responses of the amplifier in response to the initialization pulses and calculates the coefficients for the feedback compensation filter in response thereto. In the preferred embodiment, the impulse responses are averaged with respect to a threshold to provide combined responses. In the illustrative embodiment, the combined responses are Fast Fourier Transformed, reciprocated and then inverse transformed. The data during normal operation is fed back to the data capture, corrected for distortion in the feedback path from the output of the amplifier, converted to basedband, synchronized and used to provide the coefficients for the predistortion linearization engine. As a result, in the best mode, each of the coefficients used in the predistortion linearization engine can be computed by solving the matrix equation HW=S for W, where W is a vector of the weights, S is a vector of predistortion linearization engine outputs, and H is a matrix of PA return path inputs as taught herein.
摘要翻译：线性化和方法。在最一般的实施例中，本发明的线性化器包括耦合到来自所述电路的输入端和从所述电路的输出产生一组系数的表征器和响应于所述系数的预失真引擎，用于预失真输入到所述电路的信号，使得所述电路产生响应于此的线性化输出。在具体应用中，电路是在线性化器初始化操作模式期间发送一系列脉冲的功率放大器。在具体实现中，表征器响应于初始化脉冲分析放大器的有限脉冲响应，并响应于此反馈补偿滤波器计算系数。在优选实施例中，相对于阈值对脉冲响应进行平均以提供组合响应。在说明性实施例中，组合的响应是快速傅里叶变换，往复运算，然后逆变换。在正常操作期间的数据被反馈到数据采集，校正来自放大器的输出的反馈路径中的失真，被转换为基带，同步并用于为预失真线性化引擎提供系数。结果，在最佳模式下，可以通过求解W的矩阵方程式HW = S来计算预失真线性化引擎中使用的每个系数，其中W是权重的向量，S是预失真线性化引擎的向量输出，H是如本文所教导的PA返回路径输入的矩阵。

16. 发明授权

US5960040A Communication signal processors and methods 失效
标题翻译：通信信号处理器和方法
公开(公告)号：US5960040A
公开(公告)日：1999-09-28
申请号：US761103
申请日：1996-12-05
申请人： Khiem V. Cai , Allan L. Levine, Jr.
发明人： Khiem V. Cai , Allan L. Levine, Jr.
IPC分类号： H04L27/10 , H03M13/23 , H04L1/00 , H04L27/00 , H04L27/12 , H04L27/152 , H04L27/18 , H04L27/20 , H04L27/233 , H04L27/32
CPC分类号： H04L27/1525 , H04L1/0054 , H04L27/0008 , H04L27/2332 , H04L2027/0067
摘要： A digital signal processor is provided which is compatible with a large variety of modulation processes (e.g., BPSK, QPSK,.pi./4 QPSK, M-ary FSK and M-ary PSK). The processor has a transmit section which can convert input data streams into baseband I and Q signals and a receive section which can recover data streams from input baseband I and Q signals. The transmit section includes a direct I/Q modulator and a common phase modulator and the receive section includes an M-FSK to M-PSK converter and a common phase demodulator. The processor is particularly suited for realization as an application-specific integrated circuit (ASIC) which can be integrated in multiband, multimode transceivers.
摘要翻译：提供一种数字信号处理器，其与各种调制过程（例如，BPSK，QPSK，pi / 4QPSK，M-ary FSK和M-ary PSK）兼容。处理器具有可将输入数据流转换为基带I和Q信号的发送部分以及可从输入基带I和Q信号恢复数据流的接收部分。发送部分包括直接I / Q调制器和公共相位调制器，接收部分包括M-FSK至M-PSK转换器和公共相位解调器。该处理器特别适合作为专用集成电路（ASIC）的实现，该集成电路可集成在多频带多模收发器中。

17. 发明授权

US5592181A Vehicle position tracking technique 失效
标题翻译：车辆位置跟踪技术
公开(公告)号：US5592181A
公开(公告)日：1997-01-07
申请号：US443519
申请日：1995-05-18
申请人： Khiem V. Cai , Roger J. O'Connor
发明人： Khiem V. Cai , Roger J. O'Connor
IPC分类号： G01S3/48 , G01S5/04 , G01S3/02
CPC分类号： G01S5/04 , G01S3/48
摘要： A method and system for tracking the position of a moving transmitter using angle of arrival measurements from direction finding antenna arrays. Each array includes several elements, with the elements grouped to provide subarrays of different element spacings which are multiple of one half the transmitter wavelength. Ambiguity is rejected by processing angle data received from the subarrays. The signals from the arrays are processed to convert electrical phase delay into spatial angles, the spatial angle data is processed to provide the x,y position, velocity and acceleration of the transmitter. For transmitters mounted in moving vehicles, the system further processes the x,y data and applies a quality weighting factor that filters out multipath factors and permits estimation of vehicle profile information.
摘要翻译：一种用于使用来自测向天线阵列的到达角测量跟踪移动发射机的位置的方法和系统。每个阵列包括几个元件，其中元件被分组以提供不同元件间隔的子阵列，其是发射器波长的一半的倍数。通过处理从子阵列接收的角度数据来拒绝歧义。来自阵列的信号被处理以将电相位延迟转换成空间角度，处理空间角度数据以提供发射机的x，y位置，速度和加速度。对于安装在移动车辆中的发射机，系统进一步处理x，y数据，并应用滤除多路径因素的质量加权因子，并允许估计车辆档案信息。

18. 发明授权

US5271038A Distortion suppression using thresholding techniques 失效
标题翻译：使用阈值技术进行失真抑制
公开(公告)号：US5271038A
公开(公告)日：1993-12-14
申请号：US580710
申请日：1990-09-10
申请人： Khiem V. Cai
发明人： Khiem V. Cai
IPC分类号： H04B1/10
CPC分类号： H04B1/1027 , H04B2001/1063
摘要： A distortion suppressor and method for suppressing distortion that performs processing in the time domain to suppress partial time distortion of received signals, and/or the frequency domain to suppress partial band distortion of the received signals. For time domain suppression, the received signals are sampled and sample amplitudes are sorted. Based on the sorted samples, the receiver searches for two levels, S.sub.L and S.sub.M, representing clipping and removal thresholds. Any samples having amplitudes above S.sub.L are removed (zeroed), samples having amplitudes below S.sub.L are left alone, and samples having amplitudes between S.sub.L and S.sub.M are clipped to S.sub.L. The processor searches for optimum S.sub.L and S.sub.M values to maximize the signal to noise ratio of the received signals. For frequency domain suppression, the received signals are processed by a Fourier transform (FFT) processor. The spectrum of output signals from the FFT processor is sampled in a manner similar to the time domain suppression. The sample amplitudes are sorted, and the clipping and removal thresholds, S.sub.L and S.sub.M, are determined such that the output signal to noise ratio is maximized. Samples having amplitudes above S.sub.M are zeroed, and samples having amplitudes between S.sub.L and S.sub.M are clipped to S.sub.L. The resulting signal has a maximum signal to noise ratio, that maximizes receiver performance. Clipping and removal thresholds S.sub.L, S.sub.M are set with reference to the sorted amplitude profile, which determines two optimum clipping and removal threshold levels for the frequency distribution. Finally, the signals levels are clipped as stated above to maximize the suppression of interference and noise while achieving minimum distortion of the signals.
摘要翻译：用于抑制在时域中进行处理以抑制接收信号的部分时间失真的失真抑制器和/或频域以抑制接收信号的部分频带失真的失真抑制器和方法。对于时域抑制，对接收的信号进行采样并对采样幅度进行分类。基于排序的样本，接收器搜索两个级别SL和SM，表示剪切和删除阈值。任何具有高于SL值的样品都被去除（归零），幅度低于SL的样品被单独留下，并且具有SL和SM之间的幅度的样品被剪切到SL。处理器搜索最佳的SL和SM值以最大化接收信号的信噪比。对于频域抑制，接收信号由傅里叶变换（FFT）处理器处理。以与时域抑制相似的方式对来自FFT处理器的输出信号的频谱进行采样。对样本幅度进行分类，并且确定限幅和去除阈值SL和SM，使得输出信噪比最大化。振幅高于SM的样品被清零，并且具有SL和SM之间的振幅的样品被削波到SL。所得到的信号具有最大的信噪比，使接收机性能最大化。剪切和去除阈值SL，SM参考排序的幅度分布来设置，其确定了用于频率分布的两个最佳剪切和去除阈值水平。最后，如上所述限制信号电平，以最大限度地抑制干扰和噪声，同时实现信号的最小失真。

19. 发明授权

US5121408A Synchronization for entry to a network in a frequency hopping communication system 失效
标题翻译：进入频率通话系统中的网络的同步
公开(公告)号：US5121408A
公开(公告)日：1992-06-09
申请号：US422257
申请日：1989-10-16
申请人： Khiem V. Cai , Roger J. O'Connor
发明人： Khiem V. Cai , Roger J. O'Connor
IPC分类号： H04B1/709 , H04B1/713 , H04B1/7156
CPC分类号： H04B1/7156 , H04B1/709 , H04B1/713 , H04B2001/71563
摘要： Synchronization of a frequency hopping transceiver to a network by embedding synchronization codes in the pseudo-random frequency hopping transmission sequence. A receiver is implemented with a frequency detector and a correlator to generate a correlator signal in response to the synchronization codes in the pseudo-random frequency hopping transmission sequence. Detection of a peak in the correlator signal is indicative of synchronization of the receiver with the network. The network entry synchronization scheme is such that, when two transceivers A and B are communicating, a third unnetworked transceiver C extracts the hidden network entry code pattern from the A-B transmission in order to enter the network. As a part of the communication between the two transceivers A and B, transceiver A transmits a known pattern as a hidden part of the communication which allows transceiver C to enter the A-B network. This hidden code pattern permits rapid synchronization and correction of large initial time errors, and permits correction of time drift from then on.

20. 发明申请

US20120300878A1 DYNAMIC DIGITAL PRE-DISTORTION SYSTEM 有权
标题翻译：动态数字预失真系统
公开(公告)号：US20120300878A1
公开(公告)日：2012-11-29
申请号：US13567724
申请日：2012-08-06
申请人： Khiem V. Cai , David B. Rutan , Ahmad Khanifar , Armando C. Cova
发明人： Khiem V. Cai , David B. Rutan , Ahmad Khanifar , Armando C. Cova
IPC分类号： H04L25/49
CPC分类号： H04B1/62 , H03F1/3241 , H03F1/3247 , H03F1/3294 , H03F3/24 , H03F2200/336 , H03F2200/451 , H03F2201/3224 , H04B1/0475 , H04B17/13 , H04B2001/0425 , H04W52/52
摘要： A Dynamic Digital Pre-Distortion (DDPD) system is disclosed to rapidly correct power amplifier (PA) non-linearity and memory effects. To perform pre-distortion, a DDPD engine predistorts an input signal in order to cancel PA nonlinearities as the signal is amplified by the PA. The DDPD engine is implemented as a composite of one linear filter and N−1 high order term linear filters. The bank of linear filters have programmable complex coefficients. To compute the coefficients, samples from the transmit path and a feedback path are captured, and covariance matrices A and B are computed using optimized hardware. After the covariance matrices are computed, Gaussian elimination processing may be employed to compute the coefficients. Mathematical and hardware optimizations may be employed to simplify and reduce the number of multiplication operands and other operations, which can enable the DDPD system to fit within a single chip.
摘要翻译：公开了动态数字预失真（DDPD）系统来快速校正功率放大器（PA）的非线性和记忆效应。为了执行预失真，DDPD引擎预失真输入信号，以便随着信号被PA放大而取消PA非线性。 DDPD引擎实现为一个线性滤波器和N-1个高阶项线性滤波器的组合。线性滤波器组具有可编程的复系数。为了计算系数，捕获来自发射路径和反馈路径的样本，并使用优化的硬件来计算协方差矩阵A和B. 在协方差矩阵被计算之后，可以采用高斯消去处理来计算系数。可以采用数学和硬件优化来简化和减少乘法操作数和其他操作的数量，这可以使DDPD系统适合于单个芯片内。

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