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21. 发明授权

US07085330B1 Method and apparatus for amplifier linearization using adaptive predistortion 有权
标题翻译：使用自适应预失真的放大器线性化的方法和装置
公开(公告)号：US07085330B1
公开(公告)日：2006-08-01
申请号：US10153554
申请日：2002-05-22
申请人： Kedar Shirali
发明人： Kedar Shirali
IPC分类号： H04L25/03
CPC分类号： H04L27/368 , H03F1/3247 , H03F1/3282 , H03F3/24 , H03F2200/207 , H03F2201/3203
摘要： A signal processing method and apparatus capable of correcting signal distortion introduced by an RF power amplifier is disclosed, which includes the use of a buffer to store a plurality of samples representing at least a portion of an input signal intended for amplification by the RF power amplifier, the use of a self-receiver to receive an output signal generated by the RF power amplifier, the use of a synchronization unit to determine, as a matching input sample, which of the stored plurality of samples corresponds most closely to the output signal, and the use of a predistortion unit to selectively apply a distortion correction function to the input signal prior to amplification by the RF power amplifier in which the distortion correction function being derived from a relationship between the matching input sample and the output signal. This permits more precise and updateable determination of the delays involved in the RF modulation and amplification stages of the amplifier and the self-receiver, thus allowing for more precise and aggressive adaptive predistortion to be used. A phase offset correction is optionally provided to correct a phase offset in the realized sample of the output signal relative to the matching input symbol. Additionally, a sampling phase error correction unit may be provided to generate sampling alteration information to an analog-to-digital converter to cause such analog-to-digital converter to selectively alter sampling of the output signal.
摘要翻译：公开了一种能够校正由RF功率放大器引入的信号失真的信号处理方法和装置，其包括使用缓冲器来存储表示用于由RF功率放大器放大的输入信号的至少一部分的多个采样使用自接收器接收由RF功率放大器产生的输出信号，使用同步单元确定所存储的多个样本中的哪一个最接近于输出信号的匹配输入样本，以及使用预失真单元，在RF功率放大器进行放大之前，对输入信号选择性地应用失真校正功能，其中所述失真校正功能根据所述匹配输入采样与所述输出信号之间的关系导出。这允许对放大器和自身接收机的RF调制和放大级中涉及的延迟的更精确和可更新的确定，从而允许使用更精确和积极的自适应预失真。可选地提供相位偏移校正以校正输出信号相对于匹配输入符号的已实现采样中的相位偏移。另外，可以提供采样相位误差校正单元以向模数转换器产生采样改变信息，以使得这种模数转换器有选择地改变输出信号的采样。

22. 发明授权

US08571140B1 Methods and apparatus for providing a maximum likelihood (ML) decoding pipeline for quadrature phase-shift keying (QPSK) multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) receivers 有权
标题翻译：用于为正交相移键控（QPSK）多输入多输出（MIMO）正交频分复用（OFDM）接收机提供最大似然（ML）解码流水线的方法和装置
公开(公告)号：US08571140B1
公开(公告)日：2013-10-29
申请号：US13605499
申请日：2012-09-06
申请人： Konstantinos Sarrigeorgidis , Yanni Chen , Leilei Song , Kedar Shirali
发明人： Konstantinos Sarrigeorgidis , Yanni Chen , Leilei Song , Kedar Shirali
IPC分类号： H04L27/00
CPC分类号： H04L25/067 , H03M13/612 , H04L1/0045 , H04L25/03286 , H04L27/2647
摘要： Methods and apparatus are provided for performing log-likelihood ratio (LLR) computations in a pipeline. Portions of a metric used to compute LLR values are computed in one pipeline part. The portions correspond to all permutations of some received signal streams. The portions are combined with one permutation x2 of the received signal stream that was not included in the previous pipeline computation in a subsequent pipeline part to produce M values associated with a particular bit position. At each subsequent clock cycle, a different permutation of x2 is combined with the previously computed portions producing different M values. State values corresponding to different values of bit positions of the received stream are computed by finding the minimum among the M values, in each clock cycle, that affect a particular bit position. The state values are combined to compute the LLR values for the bit position in a final pipeline part.
摘要翻译：提供了在流水线中执行对数似然比（LLR）计算的方法和装置。用于计算LLR值的度量的部分在一个管道部分中计算。这些部分对应于一些接收的信号流的所有排列。这些部分与接收信号流的一个置换x2组合在一起，该置换x2未被包括在随后的流水线部分中的先前流水线计算中，以产生与特定位位置相关联的M个值。在每个随后的时钟周期，x2的不同置换与先前计算的产生不同M值的部分组合。通过在每个时钟周期内找到影响特定位位置的M个值中的最小值来计算对应于接收流的比特位置的不同值的状态值。组合状态值以计算最终流水线部分中位位置的LLR值。

23. 发明授权

US08275323B1 Clear-channel assessment in 40 MHz wireless receivers 有权
标题翻译： 40 MHz无线接收机的清晰通道评估
公开(公告)号：US08275323B1
公开(公告)日：2012-09-25
申请号：US11827958
申请日：2007-07-13
申请人： Kedar Shirali , Atul Salhotra , Zhiyu Yang
发明人： Kedar Shirali , Atul Salhotra , Zhiyu Yang
IPC分类号： H04B17/00
CPC分类号： H04W72/04 , H04B17/318 , H04W28/04 , H04W74/085
摘要： A system including an activity sensing module to sense RF activity in first and second sub-channels of a communication channel of a first wireless network. N adjacent channel interference (ACI) filter modules arranged in parallel receive signals from N antennas, respectively, filter out signals in channels adjacent to the communication channel, and generate N filtered signals, respectively, where N>2. The activity sensing module generates control signals based on the N filtered signals. A channel identification module processes the control signals, and determines that both of the first and second sub-channels are available when the RF activity originating from a second wireless network is not present in both of the first and second sub-channels, and that the first sub-channel is available when the RF activity originating from the second wireless network is present only in the second sub-channel and is less than or equal to a predetermined threshold.
摘要翻译：一种系统，包括用于感测第一无线网络的通信信道的第一和第二子信道中的RF活动的活动感测模块。 N个天线并行布置的N个相邻信道干扰（ACI）滤波器模块分别接收与通信信道相邻的信道中的信号，并分别产生N个滤波信号，其中N≥2。活动感测模块根据N个滤波信号产生控制信号。信道识别模块处理控制信号，并且当源自第二无线网络的RF活动不存在于第一和第二子信道中时，确定第一和第二子信道都可用，并且当来自第二无线网络的RF活动仅在第二子信道中存在且小于或等于预定阈值时，第一子信道可用。

24. 发明授权

US08265207B1 Methods and apparatus for providing a ML decoding pipeline for QPSK MIMO OFDM receivers 有权
标题翻译：为QPSK MIMO OFDM接收机提供ML解码流水线的方法和装置
公开(公告)号：US08265207B1
公开(公告)日：2012-09-11
申请号：US13333106
申请日：2011-12-21
申请人： Konstantinos Sarrigeorgidis , Yanni Chen , Leilei Song , Kedar Shirali
发明人： Konstantinos Sarrigeorgidis , Yanni Chen , Leilei Song , Kedar Shirali
IPC分类号： H04L27/06 , H03M13/03
CPC分类号： H04L25/067 , H03M13/612 , H04L1/0045 , H04L25/03286 , H04L27/2647
摘要： Methods and apparatus are provided for computing reliability values in a pipeline. A reliability value portion is computed, with control circuitry in a first pipeline stage, based on a difference between a received input signal value and an expected value. The reliability value portion is combined, in a second pipeline stage that follows the first pipeline stage, with a first value derived from the received input signal to generate a first reliability value. A determination is made as to whether to update the first reliability value in a third pipeline stage based on a combination of the first reliability value with a second reliability value that corresponds to a second value derived from the received input signal.
摘要翻译：提供了用于计算流水线中的可靠性值的方法和装置。基于接收到的输入信号值和预期值之间的差，计算第一流水线级中的控制电路的可靠性值部分。在靠近第一流水线级的第二流水线级中，将可靠性值部分与从所接收的输入信号导出的第一值相结合，以产生第一可靠性值。基于第一可靠性值与对应于从接收的输入信号导出的第二值相对应的第二可靠性值的组合，确定是否更新第三流水线级中的第一可靠性值。

25. 发明授权

US08040982B1 Phase-adjusted channel estimation for frequency division multiplexed channels 有权
标题翻译：用于频分复用信道的相位调整信道估计
公开(公告)号：US08040982B1
公开(公告)日：2011-10-18
申请号：US11483057
申请日：2006-07-06
申请人： Rohit Nabar , Kedar Shirali
发明人： Rohit Nabar , Kedar Shirali
IPC分类号： H04L27/06 , H04L27/28 , H04J11/00
CPC分类号： H04L25/0206 , H04L25/022 , H04L25/0224
摘要： The disclosed technology relates to estimating the frequency response of a frequency division multiplexed (FDM) channel. In accordance with one aspect of the invention, a channel estimation circuit of a receiver can compute initial estimates of the frequency response of sub-channels in the FDM channel. A phase adjustment circuit can adjust the phase components of the initial estimates to provide phase-adjusted estimates. A smoothing circuit can apply a smoothing operation to the phase-adjusted estimates to provide smoothed phase-adjusted estimates. When necessary, a reverse phase adjustment circuit can reverse the phase adjustment by adjusting the phase components of the smoothed phase-adjusted estimates to provide final channel estimates.
摘要翻译：所公开的技术涉及估计频分复用（FDM）信道的频率响应。根据本发明的一个方面，接收机的信道估计电路可以计算FDM信道中子信道的频率响应的初始估计。相位调整电路可以调整初始估计的相位分量，以提供相位调整的估计。平滑电路可以对经阶段调整的估计值进行平滑处理，以提供平滑的相位调整估计。必要时，反向相位调整电路可以通过调整平滑的相位调整估计的相位分量来反转相位调整，以提供最终的信道估计。

26. 发明申请

US20080084835A1 OPPORTUNISTIC 40 MHz MODE OF TRANSMISSION IN WIRELESS TRANSMITTERS 有权
标题翻译：机载40 MHz无线发射机传输模式
公开(公告)号：US20080084835A1
公开(公告)日：2008-04-10
申请号：US11866754
申请日：2007-10-03
申请人： Sandesh Goel , Timothy Donovan , Ken Ho , Yungping Hsu , Kedar Shirali , Atul Salhotra , Tam Tran , Chia-Chun Chung
发明人： Sandesh Goel , Timothy Donovan , Ken Ho , Yungping Hsu , Kedar Shirali , Atul Salhotra , Tam Tran , Chia-Chun Chung
IPC分类号： H04B7/00 , H04Q7/20
CPC分类号： H04W72/04 , H04W74/0808
摘要： A system includes a signal processing module and a control module. The signal processing module receives a first clear channel assessment (CCA) signal for a first sub-channel of a communication channel, increases a pulse width of the first CCA signal by a predetermined period of time, and generates a second CCA signal. The control module receives the second CCA signal and a third CCA signal for a second sub-channel of the communication channel. The control module transmits data via one of the second sub-channel and the communication channel based on the second and third CCA signals.
摘要翻译：系统包括信号处理模块和控制模块。信号处理模块接收通信信道的第一子信道的第一清除信道评估（CCA）信号，将第一CCA信号的脉冲宽度增加预定时间段，并产生第二CCA信号。控制模块接收第二CCA信号和用于通信信道的第二子信道的第三CCA信号。控制模块基于第二和第三CCA信号，经由第二子信道和通信信道中的一个发送数据。

27. 发明授权

US06985033B1 Circuits and methods for adjusting power amplifier predistortion, and power amplifiers and other devices including the same 有权
标题翻译：用于调节功率放大器预失真的电路和方法，以及功率放大器和其他器件包括相同
公开(公告)号：US06985033B1
公开(公告)日：2006-01-10
申请号：US10753007
申请日：2004-01-06
申请人： Kedar Shirali , King Chun Tsai , Wayne Loeb
发明人： Kedar Shirali , King Chun Tsai , Wayne Loeb
IPC分类号： H03F1/26
CPC分类号： H03F1/3247 , H03F2201/3233
摘要： An amplifier with adjustable (pre)distortion, a predistortion adjustment circuit, systems and networks including such amplifiers and circuits, and methods for adjusting (pre)distortion in an analog amplifier. The amplifier architecture generally includes (a) a predistortion circuit configured to (i) select a value for a predistortion function from a plurality of different predistortion values, and (ii) apply the selected predistortion value to an input signal to generate a predistorted input signal; (b) an amplifier configured to amplify the predistorted input signal and provide an output signal therefrom; and (c) an adjustment circuit configured to adjust selection of the predistortion function value in response to a predetermined parameter value of the amplifier. By adjusting the predistortion function, the amplifier provides an output signal in a linear power range over a range of amplifier parameter values and avoids overcompensation that can occur when the predistortion signal is not adjustable. Furthermore, the adjustments are made in response to changes in amplifier input and/or control parameters, enabling the amplifier to stay in the linear range, rather than respond to changes that first cause the amplifier to fall out of linearity. The systems generally include the architecture, circuit or an integrated circuit that embodies one or more of the inventive concepts disclosed herein. The methods generally include the steps of (1) predistorting an input signal in accordance with a digital predistortion function to provide a predistorted signal, (2) adjusting the digital predistortion function in response to a predetermined parameter value of an amplifier, and (3) amplifying the predistorted signal with the amplifier to produce the amplified signal.
摘要翻译：具有可调（预）失真的放大器，预失真调节电路，包括这种放大器和电路的系统和网络，以及用于在模拟放大器中调整（预）失真的方法。放大器架构通常包括（a）预失真电路，其被配置为（i）从多个不同预失真值中选择预失真函数的值，以及（ii）将所选择的预失真值应用于输入信号以产生预失真输入信号 ; （b）放大器，被配置为放大所述预失真输入信号并从其提供输出信号; 以及（c）调整电路，被配置为响应于所述放大器的预定参数值来调整所述预失真函数值的选择。通过调整预失真功能，放大器在放大器参数值的范围内提供线性功率范围内的输出信号，并避免在预失真信号不可调时可能发生的过补偿。此外，响应于放大器输入和/或控制参数的变化进行调整，使得放大器能够保持在线性范围内，而不是响应于首先使放大器脱离线性的变化。这些系统通常包括体现本文公开的一个或多个发明构思的架构，电路或集成电路。所述方法通常包括以下步骤：（1）根据数字预失真函数预失真输入信号以提供预失真信号，（2）响应于放大器的预定参数值调整数字预失真函数，以及（3）用放大器放大预失真信号以产生放大信号。

28. 发明授权

US07872962B1 System and method for producing weighted signals in a diversity communication system 有权
标题翻译：用于在分集通信系统中产生加权信号的系统和方法
公开(公告)号：US07872962B1
公开(公告)日：2011-01-18
申请号：US11447762
申请日：2006-06-05
申请人： Rohit Nabar , Kedar Shirali , Hui-Ling Lou , Jungwon Lee
发明人： Rohit Nabar , Kedar Shirali , Hui-Ling Lou , Jungwon Lee
IPC分类号： H04J11/00
CPC分类号： H04B7/084 , H04B7/0615 , H04B7/0845 , H04B2201/70706 , H04L25/0232 , H04L27/0014
摘要： The disclosed technology relates to a communication system and method in which multiple versions of a signal are processed to detect the signal. The communication system can include transmitters that communicate different versions of a signal to a receiver. The different versions are weighted versions of the signal and are communicated on different channels. The weight for a weighted signal is based on an inverse of an estimate of the phase shift of the particular channel to which the weighted signal will be communicated. The weights are also based on a unity gain such that each weighted signal has the same magnitude as the original signal. A receiver that receives the weighted signals processes the received signals to detect the original signal.
摘要翻译：所公开的技术涉及其中处理多个版本的信号以检测信号的通信系统和方法。通信系统可以包括将信号的不同版本传送到接收机的发射机。不同的版本是信号的加权版本，并且在不同的信道上进行通信。加权信号的权重基于加权信号将被传送到的特定信道的相移的估计的倒数。权重也基于单位增益，使得每个加权信号具有与原始信号相同的幅度。接收加权信号的接收机处理接收的信号以检测原始信号。

29. 发明授权

US07697449B1 Adaptively determining a data rate of packetized information transmission over a wireless channel 有权
标题翻译：通过无线信道自适应地确定分组信息传输的数据速率
公开(公告)号：US07697449B1
公开(公告)日：2010-04-13
申请号：US10988318
申请日：2004-11-12
申请人： Kedar Shirali , Ravi Narasimhan , Yungping Hsu
发明人： Kedar Shirali , Ravi Narasimhan , Yungping Hsu
IPC分类号： G01R31/08
CPC分类号： H04W28/0236 , H04L25/0206 , H04L25/0242 , H04W24/10 , H04W28/22
摘要： Systems and techniques relating to processing a signal received over a wireless channel. A technique includes adaptively determining a data rate of packetized information transmission based on both a signal quality measure of a received signal and a channel quality measure derived from the received signal, the channel quality measure being indicative of frequency selectivity in the wireless channel. An apparatus includes a channel estimator configured to be responsive to a received OFDM signal corresponding to multiple frequency tones of the channel, and configured to evaluate channel response characteristics of the frequency tones; and a channel state indicator configured to generate a channel quality measure usable along with a signal quality measure in adaptively determining a data rate of packetized information transmission, wherein the channel quality measure is generated from the channel response characteristics of the frequency tones and is indicative of frequency selectivity in the wireless channel.
摘要翻译：与处理通过无线信道接收的信号有关的系统和技术。一种技术包括基于接收信号的信号质量测量和从接收信号导出的信道质量度量自适应地确定分组化信息传输的数据速率，信道质量度量指示无线信道中的频率选择性。一种装置包括：信道估计器，被配置为响应于与所述信道的多个频率音调相对应的接收的OFDM信号，并且被配置为评估所述频率音调的信道响应特性; 以及信道状态指示符，其被配置为生成可自适应地确定分组化信息传输的数据速率的信号质量度量可用的信道质量度量，其中，信道质量度量是根据频率音调的信道响应特性产生的，并且指示频率选择性在无线信道。

30. 发明授权

US08838038B1 Clear-channel assessment in 40 MHz wireless receivers 有权
标题翻译： 40 MHz无线接收机的清晰通道评估
公开(公告)号：US08838038B1
公开(公告)日：2014-09-16
申请号：US13613996
申请日：2012-09-13
申请人： Kedar Shirali , Atul Salhotra , Zhiyu Yang
发明人： Kedar Shirali , Atul Salhotra , Zhiyu Yang
IPC分类号： H04B17/00 , H04W72/04
CPC分类号： H04W72/04 , H04B17/318 , H04W28/04 , H04W74/085
摘要： A system including a plurality of filter modules to respectively communicate with a plurality of antennas, filter signals from channels other than a communication channel of a first wireless network, where the communication channel includes a first channel and a second channel, and generate a plurality of signals. A sensing module senses, based on the plurality of signals, whether radio frequency signals from a second network are present in at least one of the first channel and the second channel, and generates a plurality of control signals indicating presence or absence of the radio frequency signals in at least one of the first channel and the second channel. A channel identification module determines, based on the plurality of control signals, availability of the first channel and the second channel in response to whether the radio frequency signals are present in the first channel and the second channel.
摘要翻译：一种系统，包括分别与多个天线通信的多个滤波器模块，从除第一无线网络的通信信道之外的信道中滤除信号，其中所述通信信道包括第一信道和第二信道，并且生成多个信号。感测模块基于多个信号来感测来自第二网络的射频信号是否存在于第一信道和第二信道中的至少一个中，并且生成指示有无射频的多个控制信号在第一通道和第二通道中的至少一个通道中的信号。信道识别模块响应于射频信号是否存在于第一信道和第二信道中，基于多个控制信号确定第一信道和第二信道的可用性。

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