公开(公告)号：US07751495B1

公开(公告)日：2010-07-06

申请号：US11851237

申请日：2007-09-06

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 ,  H04L23/02 ,  H04B1/40

CPC classification number: H04B7/0678 ,  H04L1/06

Abstract: A wireless communication system uses a spatial spreading matrix to simultaneously transmit various different streams of encoded symbol data simultaneously via multiple transmission antennas, wherein the spatial spreading matrix is designed to assure that the different transmission antennas provide equal power output in the presence of both correlated and uncorrelated data within the different encoded symbol streams. The use of this spatial spreading matrix reduces or eliminates the condition in which a particular one of the transmission antennas needs to operate at an output power that is significantly higher than the others of the transmission antennas, which might lead to saturation of, or to the non-linear or abnormal operation of a power amplifier associated with the particular transmission antenna, resulting in improper amplification for that particular transmission antenna.

Abstract translation: 无线通信系统使用空间扩展矩阵同时通过多个发射天线发射各种不同的编码符号数据流，其中空间扩展矩阵被设计为确保不同的发射天线在存在相关和相关的情况下提供相等的功率输出 不同编码符号流内的不相关数据。 这种空间扩展矩阵的使用减少或消除了特定一个发射天线需要以明显高于发射天线其他发射天线的输出功率来工作的条件，这可能导致饱和， 与特定发射天线相关联的功率放大器的非线性或异常操作，导致该特定发射天线的不正确的放大。

公开(公告)号：US07697449B1

公开(公告)日：2010-04-13

申请号：US10988318

申请日：2004-11-12

Applicant: Kedar Shirali ,  Ravi Narasimhan ,  Yungping Hsu

Inventor： Kedar Shirali ,  Ravi Narasimhan ,  Yungping Hsu

IPC: G01R31/08

CPC classification number: H04W28/0236 ,  H04L25/0206 ,  H04L25/0242 ,  H04W24/10 ,  H04W28/22

Abstract: 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.

Abstract translation: 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。

公开(公告)号：US08838038B1

公开(公告)日：2014-09-16

申请号：US13613996

申请日：2012-09-13

Applicant: Kedar Shirali ,  Atul Salhotra ,  Zhiyu Yang

Inventor： Kedar Shirali ,  Atul Salhotra ,  Zhiyu Yang

IPC: H04B17/00 ,  H04W72/04

CPC classification number: H04W72/04 ,  H04B17/318 ,  H04W28/04 ,  H04W74/085

Abstract: 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.

Abstract translation: 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。

公开(公告)号：US08369469B1

公开(公告)日：2013-02-05

申请号：US13085350

申请日：2011-04-12

Applicant: Atul Salhotra ,  Kedar Shirali ,  Zhiyu Yang ,  Hui-Ling Lou

Inventor： Atul Salhotra ,  Kedar Shirali ,  Zhiyu Yang ,  Hui-Ling Lou

IPC: H04L25/08

CPC classification number: H04B7/0857 ,  H04B7/084 ,  H04L2025/03414 ,  H04L2025/03426

Abstract: A method including: receiving, through a wireless channel, a plurality of modulated signals at a plurality of antennas, wherein each antenna receives a corresponding modulated signal; generating a plurality of autocorrelated signals by autocorrelating the plurality of modulated signals; determining whether a signal strength associated with each modulated signal is (i) below a threshold or (ii) above the threshold; for each modulated signal having a signal strength below the threshold, disabling the antenna that received the modulated signal having the signal strength below the threshold; combining the modulated signals having a signal strength above the threshold; generating weighted autocorrelated signals based on (i) the plurality of autocorrelated signals and (ii) the combined modulated signals; generating a combined weighted signal by summing the weighted autocorrelation signals; demodulating the combined weighted signal; and determining a state of the wireless channel based on the demodulation of the combined weighted signal.

Abstract translation: 一种方法，包括：通过无线信道在多个天线处接收多个调制信号，其中每个天线接收对应的调制信号; 通过对所述多个调制信号进行自相关来生成多个自相关信号; 确定与每个调制信号相关联的信号强度是否是（i）低于阈值或（ii）高于阈值; 对于具有低于阈值的信号强度的每个调制信号，禁用接收到信号强度低于阈值的调制信号的天线; 组合具有高于阈值的信号强度的调制信号; 基于（i）所述多个自相关信号和（ii）所述组合调制信号产生加权自相关信号; 通过对加权的自相关信号求和来产生组合的加权信号; 解调组合加权信号; 以及基于所述组合加权信号的解调来确定所述无线信道的状态。

公开(公告)号：US20120057492A1

公开(公告)日：2012-03-08

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: H04L12/26 ,  H04W4/00

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：US08098774B1

公开(公告)日：2012-01-17

申请号：US12140022

申请日：2008-06-16

Applicant: Konstantinos Sarrigeorgidis ,  Yanni Chen ,  Leilei Song ,  Kedar Shirali

Inventor： Konstantinos Sarrigeorgidis ,  Yanni Chen ,  Leilei Song ,  Kedar Shirali

IPC: H04L27/06 ,  H03M13/03

CPC classification number: H04L25/067 ,  H03M13/612 ,  H04L1/0045 ,  H04L25/03286 ,  H04L27/2647

Abstract: Methods and apparatus are provided for performing LLR value 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.

Abstract translation: 提供了在流水线中执行LLR值计算的方法和装置。 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。

公开(公告)号：US08081692B1

公开(公告)日：2011-12-20

申请号：US12171067

申请日：2008-07-10

Applicant: Hongyuan Zhang ,  Kedar Shirali ,  Arul Durai Murugan Palanivelu

Inventor： Hongyuan Zhang ,  Kedar Shirali ,  Arul Durai Murugan Palanivelu

IPC: H04K1/10 ,  H04L27/28

CPC classification number: H04L27/34 ,  H04L25/03343 ,  H04L27/2601

Abstract: A sub-matrix is selected from an estimated multiple input, multiple output (MIMO) channel matrix, wherein the estimated MIMO channel matrix is constructed based on a codebook. A singular value decomposition (SVD) is calculated based on the sub-matrix. A steering matrix is calculated based on the SVD and the codebook.

Abstract translation: 从估计的多输入多输出（MIMO）信道矩阵中选择一个子矩阵，其中基于码本构建估计的MIMO信道矩阵。 基于子矩阵计算奇异值分解（SVD）。 基于SVD和码本计算导向矩阵。

公开(公告)号：US08050200B2

公开(公告)日：2011-11-01

申请号：US11866754

申请日：2007-10-03

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：US20110261895A1

公开(公告)日：2011-10-27

申请号：US13178387

申请日：2011-07-07

Applicant: Hongyuan Zhang ,  Rohit U. Nabar ,  Kedar Shirali ,  Peter Loc

Inventor： Hongyuan Zhang ,  Rohit U. Nabar ,  Kedar Shirali ,  Peter Loc

IPC: H04W4/00

CPC classification number: H04B7/0413 ,  H04B7/0617 ,  H04B17/21 ,  H04L25/0204 ,  H04L25/0228 ,  H04L25/03343 ,  H04L2025/03414 ,  H04L2025/03426 ,  H04L2025/03802

Abstract: A transmitter beamforming technique for use in a MIMO wireless communication system determines a partial description of a reverse channel without determining a full dimensional description of the reverse channel. A correction matrix is developed from the partial description of the reverse channel and a description of the forward channel. The correction matrix is used to process signals to be transmitted via the forward channel, and a steering matrix is used to perform beamforming in the forward channel.

Abstract translation: 用于MIMO无线通信系统的发射机波束成形技术确定反向信道的部分描述，而不确定反向信道的全维度描述。 从反向信道的部分描述和正向信道的描述开发校正矩阵。 校正矩阵用于处理要经由正向信道发送的信号，并且使用导引矩阵来在前向信道中执行波束成形。

公开(公告)号：US07532563B1

公开(公告)日：2009-05-12

申请号：US10799548

申请日：2004-03-11

Applicant: Kedar Shirali ,  Hemanth Sampath

Inventor： Kedar Shirali ,  Hemanth Sampath

IPC: H04J9/00 ,  H04L5/04

CPC classification number: H04L5/0048 ,  H04L25/0226 ,  H04L27/2613 ,  H04L27/2657

Abstract: An OFDM (Orthogonal Frequency Division Multiplexing) system may utilize pilot symbol structures including two or more pilot symbols with pilot information on alternate tones. The pilot information in one symbol is transmitted on mirror tones in another of the symbols. The pilot symbol structure may include a copy of one of the pilot symbols to aid in frequency offset estimation.

Abstract translation: OFDM（正交频分复用）系统可以使用包括两个或更多个导频符号的导频符号结构与导频信息在交替音调上。 一个符号中的导频信息以另一个符号的镜像音发送。 导频符号结构可以包括导频符号之一的副本以辅助频率偏移估计。