公开(公告)号：US07362821B1

公开(公告)日：2008-04-22

申请号：US11412637

申请日：2006-04-27

Applicant: Kedar Shirali

Inventor： Kedar Shirali

IPC: H04L25/03

CPC classification number: H04L27/368 ,  H03F1/3247 ,  H04L2027/0067

Abstract: A distortion correction circuit comprises memory that stores N samples of an input signal that occur at N different times, where N is an integer greater than two. A self-receiver samples an output signal that is generated by an RF power amplifier and that is based on said input signal. A synchronization unit selects one of said N samples by comparing said sampled output signal to said N samples. A predistortion unit generates a distortion correction function based on said selected one of said N samples and said output signal.

Abstract translation: 失真校正电路包括存储在N个不同时间发生的输入信号的N个采样的存储器，其中N是大于2的整数。 自我接收器对由RF功率放大器产生并且基于所述输入信号的输出信号进行采样。 同步单元通过将所述采样的输出信号与所述N个采样进行比较来选择所述N个采样之一。 预失真单元基于所述N个采样中的所选择的一个和所述输出信号产生失真校正功能。

公开(公告)号：US08958437B1

公开(公告)日：2015-02-17

申请号：US13437396

申请日：2012-04-02

Applicant: Atul Salhotra ,  Kedar Shirali

Inventor： Atul Salhotra ,  Kedar Shirali

IPC: H04L12/413 ,  H04W74/08 ,  H04L1/00 ,  H04L12/801

CPC classification number: H04W74/0816 ,  H04L1/0034 ,  H04L12/413 ,  H04L47/135 ,  H04W74/0825

Abstract: A network station includes a sampling device configured to generate samples of radio frequency activity on a medium. A first correlator is configured to autocorrelate the samples based on a first delay to generate a first autocorrelation value. The first delay matches periodicity of a jam signal. The jam signal indicates a second station is to transmit data. The second station is separate from the network station. A second correlator is configured to autocorrelate the samples to generate a second autocorrelation value. The second autocorrelation value indicates whether the radio frequency activity includes periodic noise. A controller is configured to prevent the network station from transmitting a radio frequency signal on the medium based each of the first autocorrelation value and the second autocorrelation value.

Abstract translation: 网络站包括被配置为在介质上生成射频活动样本的采样设备。 第一相关器被配置为基于第一延迟来自相关样本，以产生第一自相关值。 第一个延迟匹配卡纸信号的周期。 阻塞信号指示第二站要发送数据。 第二站与网络站分开。 第二相关器被配置为自相关样本以产生第二自相关值。 第二自相关值指示射频活动是否包括周期性噪声。 控制器被配置为基于第一自相关值和第二自相关值的每一个来防止网络站在介质上发送射频信号。

公开(公告)号：US08539304B1

公开(公告)日：2013-09-17

申请号：US13090642

申请日：2011-04-20

Applicant: Kedar Shirali ,  Rohit U. Nabar ,  Vikas Gulati ,  Sudhir Srinivasa

Inventor： Kedar Shirali ,  Rohit U. Nabar ,  Vikas Gulati ,  Sudhir Srinivasa

IPC: H03M13/00

CPC classification number: H03M13/6561 ,  H03M13/116 ,  H03M13/1185 ,  H03M13/2906 ,  H03M13/611 ,  H03M13/6527

Abstract: A low-density parity check (LDPC) encoder that calculate parity check values for a message using an LDPC parity check matrix is provided. A matrix-vector multiplication unit is operative to multiply a portion of the LDPC parity check matrix and the message to obtain an intermediate vector. A parallel recursion unit is operative to recursively calculate a first plurality of parity check values for the message based on the intermediate vector and to recursively calculate a second plurality of parity check values for the message based on the intermediate vector. The first plurality of parity check values are calculated in parallel with the second plurality of parity check values.

Abstract translation: 提供了使用LDPC奇偶校验矩阵计算消息的奇偶校验值的低密度奇偶校验（LDPC）编码器。 矩阵向量乘法单元用于将LDPC奇偶校验矩阵和消息的一部分相乘以获得中间向量。 并行递归单元用于基于中间向量递归地计算消息的第一多个奇偶校验值，并且基于中间向量递归地计算消息的第二多个奇偶校验值。 与第二多个奇偶校验值并行计算第一多个奇偶校验值。

公开(公告)号：US08526541B1

公开(公告)日：2013-09-03

申请号：US13530285

申请日：2012-06-22

Applicant: Sergey Timofeev ,  Atul Salhotra ,  Kedar Shirali ,  Srinivasa H. Garlapati

Inventor： Sergey Timofeev ,  Atul Salhotra ,  Kedar Shirali ,  Srinivasa H. Garlapati

IPC: H04L25/06 ,  H04L25/10

CPC classification number: H04L25/062 ,  H03D2200/0047

Abstract: An apparatus has demodulation circuitry to demodulate a radio frequency signal and produce a baseband signal, wherein the radio frequency signal comprises a periodic signal having a predetermined period. An analog-to-digital converter converts the baseband signal into a digital signal that comprises a periodic signal having the predetermined period. A first DC offset adjustment circuit estimates a DC offset contained in the digital signal based on digital samples in a sample period having a length equal to the predetermined period. A second DC offset adjustment circuit estimates the DC offset contained in the digital signal. A selection circuit selects one of the first DC offset adjustment circuit or the second DC offset adjustment circuit to be used to estimate the DC offset contained in the digital signal.

Abstract translation: 一种装置具有用于解调射频信号并产生基带信号的解调电路，其中射频信号包括具有预定周期的周期信号。 模数转换器将基带信号转换成包括具有预定周期的周期信号的数字信号。 第一DC偏移调整电路基于长度等于预定周期的采样周期中的数字采样来估计包含在数字信号中的DC偏移。 第二DC偏移调整电路估计包含在数字信号中的DC偏移。 选择电路选择要用于估计包含在数字信号中的DC偏移的第一DC偏移调整电路或第二DC偏移调整电路中的一个。

公开(公告)号：US08498361B1

公开(公告)日：2013-07-30

申请号：US13493160

申请日：2012-06-11

Applicant: Konstantinos Sarrigeorgidis ,  Kedar Shirali

Inventor： Konstantinos Sarrigeorgidis ,  Kedar Shirali

IPC: H04B7/02

CPC classification number: H04L25/03891 ,  H04B7/0413 ,  H04L1/004 ,  H04L1/005 ,  H04L1/0054 ,  H04L1/0625 ,  H04L5/0023 ,  H04L25/0204 ,  H04L25/0242 ,  H04L25/0244 ,  H04L27/2601 ,  H04L2025/03414 ,  H04L2025/03636 ,  H04L2025/03649

Abstract: An estimate of a multiple input, multiple output (MIMO) channel is computed, and an equalizer to be applied to signals received via the MIMO channel is computed. The equalizer is initialized based on the estimate of the MIMO channel. The equalizer is applied to a received signal, and the received signal is demodulated to generate a demodulated signal. The demodulated signal is decoded according to an error correction code to generate decoded data, and the decoded data is re-encoded according to the error correction code to generate re-encoded data. The re-encoded data is re-modulated to generate a re-modulated signal. The received signal is compared to the re-modulated signal, and the equalizer is updated based on the comparison. After updating the equalizer, the equalizer is applied to the received signal.

Abstract translation: 计算多输入多输出（MIMO）信道的估计，并且计算要应用于经由MIMO信道接收的信号的均衡器。 基于MIMO信道的估计来初始化均衡器。 均衡器被应用于接收信号，并且接收的信号被解调以产生解调信号。 根据纠错码对解调后的信号进行解码，生成解码数据，根据纠错码重新编码解码后的数据，生成再编码数据。 重新编码的数据被重新调制以产生重新调制的信号。 将接收的信号与再调制信号进行比较，并且基于该比较来更新均衡器。 在更新均衡器之后，均衡器被应用于接收到的信号。

公开(公告)号：US08494084B1

公开(公告)日：2013-07-23

申请号：US11598563

申请日：2006-11-13

Applicant: Rohit Nabar ,  Kedar Shirali ,  Hui-Ling Lou

Inventor： Rohit Nabar ,  Kedar Shirali ,  Hui-Ling Lou

IPC: H04L25/49

CPC classification number: H04B7/043 ,  H04B7/0413 ,  H04B7/0617 ,  H04B7/0669 ,  H04L1/0003 ,  H04L1/0009 ,  H04L1/0026 ,  H04L1/0054 ,  H04L1/0071 ,  H04L1/06 ,  H04L25/03961

Abstract: A beamforming technique used in a MIMO wireless transmission system determines a transmitter beamforming steering matrix using a matrix equalizer of a transmitter or a receiver within the MIMO communication system, to thereby increase the speed and/or to decrease the processing needed to implement effective beamforming within the transmitter of the communication system. While this beamforming technique may not provide the best possible set of steering coefficients that obtain the best possible transmission and reception in the communication system, this technique can provide increased performance over no beamforming without significantly increasing the processing overhead of the transmission system. This beamforming technique can used when a transmitter, with multiple transmitter antennas, is used to communicate with one or with multiple receivers within the communication system.

Abstract translation: 在MIMO无线传输系统中使用的波束成形技术使用MIMO通信系统内的发射机或接收机的矩阵均衡器确定发射机波束成形导引矩阵，从而提高速度和/或减少实现有效波束成形所需的处理 通信系统的发射机。 虽然该波束形成技术可能不提供在通信系统中获得最佳可能传输和接收的最佳可能的转向系数集合，但是该技术可以在无波束成形的情况下提供更高的性能，而不会显着增加传输系统的处理开销。 当具有多个发射机天线的发射机用于与通信系统内的一个或多个接收机通信时，可以使用该波束成形技术。

公开(公告)号：US08483634B1

公开(公告)日：2013-07-09

申请号：US13549887

申请日：2012-07-16

Applicant: Hongyuan Zhang ,  Zhiyu Yang ,  Kedar Shirali ,  Atul Salhotra

Inventor： Hongyuan Zhang ,  Zhiyu Yang ,  Kedar Shirali ,  Atul Salhotra

IPC: H04B17/02 ,  H04B1/16

CPC classification number: H04L27/0012 ,  H04B7/082 ,  H04L23/02 ,  H04L25/0262 ,  H04L27/2071

Abstract: A wireless networking receiver with digital antenna switching selects an antenna with an 802.11b signal based on a signal metric, such as the highest signal quality or highest peak amplitude. In one embodiment, the receiver comprises a plurality of antennas that may each receive one of a plurality of RF signals conforming to the IEEE 802.11b standard. The receiver may have multiple antennas for use with the IEEE 802.11n standard, but may receive signals conforming to the 802.11b standard. The receiver also comprises a carrier sense circuit configured to calculate a signal metric for each of the signals and further configured to generate a selection signal signifying one of the signals, based on the signal metric. The receiver further comprises a multiplexer configured to output one of the signals, based on the selection signal.

Abstract translation: 具有数字天线切换的无线网络接收机基于诸如最高信号质量或最高峰值幅度的信号度量来选择具有802.11b信号的天线。 在一个实施例中，接收机包括可以各自接收符合IEEE 802.11b标准的多个RF信号中的一个的多个天线。 接收机可以具有用于IEEE 802.11n标准的多个天线，但是可以接收符合802.11b标准的信号。 接收机还包括被配置为计算每个信号的信号度量的载波侦听电路，并进一步被配置为基于信号度量产生表示信号之一的选择信号。 接收机还包括多路复用器，配置为基于选择信号输出信号之一。

公开(公告)号：US08477869B1

公开(公告)日：2013-07-02

申请号：US13567763

申请日：2012-08-06

Applicant: Arul Durai Murugan Palanivelu ,  Hui-Ling Lou ,  Kedar Shirali ,  Rohit U. Nabar ,  Atul Salhotra

Inventor： Arul Durai Murugan Palanivelu ,  Hui-Ling Lou ,  Kedar Shirali ,  Rohit U. Nabar ,  Atul Salhotra

IPC: H04B7/02 ,  H04B1/40 ,  H04L23/02

CPC classification number: H04B7/0678 ,  H04L1/06

Abstract: A symbol encoder unit is configured to produce two or more encoded spatial data streams, wherein a number, NSS, of the encoded spatial data streams is less than a number, NTX, of transmission antennas to be used to transmit the encoded spatial data streams. A spatial spreading unit is configured to utilize a spatial spreading matrix Q to distribute two or more encoded spatial data streams to the transmission antennas. Q has NTX rows and NSS columns, and Q satisfies one or more of the following two constraints:  ∑ l = 1 N SS ⁢ Q ⁡ ( t , l )  2 = A t ⁢ B ( a ) for all t=1 . . . NTX., or  ∑ l = 1 N SS ⁢ S l ⁢ Q ⁡ ( t , l )  2 = A t ⁢ B ( b ) for all t=1 . . . NTX when Sl is equal to (i)−1 or (ii) 1. Q(t,l) is a component of Q at row t, column l, Sl is a symbol in an 1-th spatial stream. B is a constant, and A1, A2, . . . , ANTX is a sequence of constants.

Abstract translation: 符号编码器单元被配置为产生两个或更多个编码的空间数据流，其中编码的空间数据流的数量NSS小于要用于发送编码的空间数据流的发送天线的数目NTX。 空间扩展单元被配置为利用空间扩展矩阵Q将两个或更多个经编码的空间数据流分配到发射天线。 Q具有NTX行和NSS列，并且Q满足以下两个约束中的一个或多个：Σl = 1 N SS Q⁡（t，l）ert 2 = A t B（a）对于所有t = 1 。 。 。 NTX。或Σl = 1 N SS S l Q⁡（t，l）ert 2 = A t B（b）对于所有t = 1。 。 。 当S1等于（i）-1或（ii）1时，NTX为（i，i），Q（t，l）为第t列第1列中的Q的分量，S1为第1个空间流中的符号。 B是常数，A1，A2。 。 。 ANTX是常数序列。

公开(公告)号：US08441967B2

公开(公告)日：2013-05-14

申请号：US13279520

申请日：2011-10-24

Applicant: Sandesh Goel ,  Timothy J. Donovan ,  Ken Kinwah Ho ,  Yungping Hsu ,  Kedar Shirali ,  Atul Salhotra ,  Tam Tran ,  Chia-Chun Chung

Inventor： Sandesh Goel ,  Timothy J. Donovan ,  Ken Kinwah Ho ,  Yungping Hsu ,  Kedar Shirali ,  Atul Salhotra ,  Tam Tran ,  Chia-Chun Chung

IPC: H04B1/44 ,  G06F11/00 ,  H04L12/43

CPC classification number: H04W72/04 ,  H04W74/0808

Abstract: 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.

Abstract translation: 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。

公开(公告)号：US08411786B1

公开(公告)日：2013-04-02

申请号：US13346476

申请日：2012-01-09

Applicant: Leilei Song ,  Nabar U. Rohit ,  Hui-Ling Lou ,  Kedar Shirali

Inventor： Leilei Song ,  Nabar U. Rohit ,  Hui-Ling Lou ,  Kedar Shirali

IPC: H04B7/02

CPC classification number: H04L27/0008 ,  H04L1/0003 ,  H04L1/0009 ,  H04L1/0036 ,  H04L27/22 ,  H04L27/38

Abstract: One or more communications parameters associated with a multiple input, multiple output (MIMO) signal transmitted by a transmitter are identified. The one or more communications parameters include one or more of (i) a number of receive antennas via which the MIMO signal is received, (ii) a number of spatial streams in the MIMO signal, and (iii) a signal to noise ratio (SNR) corresponding to the MIMO signal. A particular data detection technique of a plurality of data detection techniques employed by a receiver is selected in accordance with at least one of the one or more communications parameters.

Abstract translation: 识别与由发射机发射的多输入多输出（MIMO）信号相关联的一个或多个通信参数。 所述一个或多个通信参数包括以下中的一个或多个：（i）接收MIMO信号的多个接收天线，（ii）MIMO信号中的多个空间流，以及（iii）信噪比（ SNR）。 根据一个或多个通信参数中的至少一个来选择由接收机采用的多个数据检测技术的特定数据检测技术。