公开(公告)号：US06813311B1

公开(公告)日：2004-11-02

申请号：US09525452

申请日：2000-03-14

申请人： Debajyoti Pal ,  Chung-Li Lu ,  Sujai Chari

发明人： Debajyoti Pal ,  Chung-Li Lu ,  Sujai Chari

IPC分类号： H04B138

CPC分类号： H04B3/23

摘要： The present invention, generally speaking, provides for cancellation of non-linear distortions within the echo path of a communications system by characterizing the nonlinearity, performing digital processing of a data signal to cause substantially the same nonlinearity to be applied to the data signal, and inputting a resulting data signal to a non-linear echo-cancellation path. In an exemplary embodiment, the non-linear echo-cancellation path includes as a nonlinear echo canceller a transversal filter or the like. A separate linear echo cancellation path is also provided. Training of the nonlinear echo canceller follows training of the linear echo canceller. This technique is particularly applicable to cancelling the effects of DAC nonlinearity, which can be readily characterized. Using this technique, cancellation improvement of about 3dB can readily be obtained. Alternatively, instead of achieving a lower residual echo floor, the linearity requirements for the transmit DAC can be relaxed. A lower number of bits of precision allows for lower DAC power consumption. The technique is particularly applicable to DSL applications.

摘要翻译： 本发明一般来说通过表征非线性来提供消除通信系统的回波路径内的非线性失真，执行数据信号的数字处理以使得基本上相同的非线性被应用于数据信号，以及 将得到的数据信号输入到非线性回波消除路径。 在示例性实施例中，非线性回波消除路径包括作为非线性回波消除器的横向滤波器等。 还提供了单独的线性回波消除路径。 非线性回波消除器的训练遵循线性回波消除器的训练。 该技术特别适用于消除DAC非线性的影响，可以很容易地表征。 使用这种技术，可以容易地获得约3dB的消除改善。 或者，代替实现较低的残余回波层，可以放宽发射DAC的线性要求。 较低数位的精度允许较低的DAC功耗。 该技术特别适用于DSL应用。

公开(公告)号：US06542477B1

公开(公告)日：2003-04-01

申请号：US09281903

申请日：1999-03-31

申请人： Debajyoti Pal ,  Sujai Chari ,  Christopher Hansen ,  Chung-Li Lu

发明人： Debajyoti Pal ,  Sujai Chari ,  Christopher Hansen ,  Chung-Li Lu

IPC分类号： H04B320

CPC分类号： H04B3/235 ,  H04B3/23

摘要： The present invention, generally speaking, provides a digitally-tunable, echo-cancelling analog front end (AFE) for wireline digital communications. The analog front end is especially useful in a High-bit-rate Digital Subscriber Line (HDSL) or HDSL2 environment. An analog echo simulation path is provided capable of simulating echo from a wide variety of echo paths. Digitally controlled attenuators are provided in the transmission path and in the analog echo simulation path. Also provided is a digital-tunable equalizer stage. The equalizer stage is tuned to match the characteristics of the receive path. The same arrangement may be adapted for various DSL technologies, i.e., xDSL. There results an analog front end that is well-adapted to high-speed wireline communications.

摘要翻译： 本发明一般地提供用于有线数字通信的数字可调谐回声消除模拟前端（AFE）。 模拟前端在高比特率数字用户线（HDSL）或HDSL2环境中特别有用。 提供了能够模拟来自各种回波路径的回波的模拟回波模拟路径。 数字控制衰减器设置在传输路径和模拟回波模拟路径中。 还提供了数字可调均衡器级。 调整均衡器级以匹配接收路径的特性。 相同的布置可以适用于各种DSL技术，即xDSL。 结果是模拟前端非常适合高速有线通信。

公开(公告)号：US08942317B2

公开(公告)日：2015-01-27

申请号：US13543481

申请日：2012-07-06

申请人： Sujai Chari

发明人： Sujai Chari

IPC分类号： H04L27/00 ,  H04L27/26 ,  H04L7/04

CPC分类号： H04L27/2657 ,  H04L7/042 ,  H04L27/0014 ,  H04L2027/003 ,  H04L2027/0048 ,  H04L2027/0095

摘要： Apparatuses, methods and systems for mitigating carrier offset of a received signal are disclosed. One embodiment of a receiver includes a receiver chain operative to receive a communication signal from a desired transmitter, and a controller operative to determine a carrier offset correction based on prior reception of communication signals from the desired transmitter. The receiver chain is operative to generate a carrier offset corrected received signal by applying the carrier offset correction to the received communication signal, and a correlation processor operative to correlate the carrier offset corrected received communication signal with a known sequence.

摘要翻译： 公开了用于减轻接收信号的载波偏移的装置，方法和系统。 接收机的一个实施例包括可操作以从期望的发射机接收通信信号的接收机链路，以及控制器，用于根据来自所需发射机的通信信号的先前接收来确定载波偏移校正。 接收器链可操作以通过对所接收的通信信号应用载波偏移校正来产生载波偏移校正的接收信号，以及相关处理器，用于将载波偏移校正的接收通信信号与已知序列进行相关。

公开(公告)号：US07978748B2

公开(公告)日：2011-07-12

申请号：US12001339

申请日：2007-12-11

申请人： Daryl Arnold Kaiser ,  Sujai Chari

发明人： Daryl Arnold Kaiser ,  Sujai Chari

IPC分类号： H04B1/73

CPC分类号： H04B1/7156 ,  H04B2001/71563 ,  H04L5/0023 ,  H04L5/0037 ,  Y10T137/7838 ,  Y10T137/7904

摘要： Methods and systems of a receiver selecting a subset of plurality of frequency hopping bands for synchronization of the receiver are disclosed. One method includes the receiver determining a receive signal quality metric for each band of the plurality of frequency hopping bands, and selecting at least one synchronization band as a subset of the plurality of frequency hopping bands for synchronization based on the receive signal quality metric of each of the plurality of frequency hopping bands.

摘要翻译： 公开了接收机选择用于接收机同步的多个跳频频带的子集的接收机的方法和系统。 一种方法包括接收机确定多个跳频频带中的每个频带的接收信号质量度量，并且基于每个频带的接收信号质量度量，选择至少一个同步频带作为用于同步的多个跳频频带的子集 的多个跳频带。

公开(公告)号：US20100098047A1

公开(公告)日：2010-04-22

申请号：US12288504

申请日：2008-10-21

申请人： Xiaoming Zhou ,  Patrick Worfolk ,  Sujai Chari

发明人： Xiaoming Zhou ,  Patrick Worfolk ,  Sujai Chari

IPC分类号： H04J3/00

CPC分类号： H04L47/10 ,  H04L47/14 ,  H04L47/2416 ,  H04L47/25 ,  H04W28/14 ,  H04W28/22

摘要： Embodiments for setting a data rate of encoded data of a transmitter are disclosed. One method includes determining a physical layer transmission rate based on a transmission link quality of a link, estimating a transmission throughput that can be transmitted over the link ensuring a level of Quality of Service (QOS) requirement, and the transmitter adjusting the data rate of the encoded data based on the estimated transmission throughput.

摘要翻译： 公开了用于设置发射机的编码数据的数据速率的实施例。 一种方法包括基于链路的传输链路质量确定物理层传输速率，估计可以通过链路传输的传输吞吐量，确保服务质量（QOS）要求的水平，并且发射机调整数据速率 基于所估计的传输吞吐量的编码数据。

公开(公告)号：US08737545B2

公开(公告)日：2014-05-27

申请号：US13326248

申请日：2011-12-14

申请人： Sujai Chari ,  Ssu-Pin Ma

发明人： Sujai Chari ,  Ssu-Pin Ma

IPC分类号： H04L27/08

CPC分类号： H03G3/3068 ,  H04B2001/1054

摘要： Apparatuses, methods and systems of selecting a gain setting of a receiver chain are disclosed. One method includes bypassing a filter portion of the receiver chain and sampling a bypass receive signal while the filter portion of the receiver chain is bypassed. If the sampled bypass receive signal is determined to be saturated greater than a threshold, then selecting a gain setting of the receive chain as a function of the saturation. Further, the filter portion of the receive chain is included while sampling a receive signal with the selected gain setting.

摘要翻译： 公开了选择接收机链的增益设置的设备，方法和系统。 一种方法包括绕过接收器链的滤波器部分并对旁路接收信号进行采样，同时接收器链的滤波器部分被旁路。 如果采样旁路接收信号被确定为饱和大于阈值，则选择接收链的增益设置作为饱和度的函数。 此外，包括接收链的滤波器部分，同时采用所选择的增益设置对接收信号进行采样。

公开(公告)号：US08693561B2

公开(公告)日：2014-04-08

申请号：US13423113

申请日：2012-03-16

申请人： Meesaraganda Surendra Raju ,  Mohan Karnam ,  Sujai Chari

发明人： Meesaraganda Surendra Raju ,  Mohan Karnam ,  Sujai Chari

IPC分类号： H04K1/10 ,  H04L27/28

CPC分类号： H04L25/0204 ,  H04L25/03292 ,  H04L27/2647 ,  H04L2025/03414 ,  H04L2025/03426 ,  H04L2025/03726

摘要： Apparatuses, methods and systems of receive signal detection of a multi-carrier signal are disclosed. One method includes receiving a multi-carrier signal, determining a characteristic of each sub-carrier of the multi-carrier signal, and selecting a one of a plurality of receive signal detection techniques for each sub-carrier of the multi-carrier signal based on the determined characteristic of the sub-carrier.

摘要翻译： 公开了多载波信号的接收信号检测的装置，方法和系统。 一种方法包括接收多载波信号，确定多载波信号的每个子载波的特性，以及基于多载波信号的每个子载波选择多个接收信号检测技术中的一个，基于 所确定的子载波的特性。

公开(公告)号：US20140010326A1

公开(公告)日：2014-01-09

申请号：US13543481

申请日：2012-07-06

申请人： Sujai Chari

发明人： Sujai Chari

IPC分类号： H04L7/02 ,  H04B1/14 ,  H04L27/06

CPC分类号： H04L27/2657 ,  H04L7/042 ,  H04L27/0014 ,  H04L2027/003 ,  H04L2027/0048 ,  H04L2027/0095

摘要： Apparatuses, methods and systems for mitigating carrier offset of a received signal are disclosed. One embodiment of a receiver includes a receiver chain operative to receive a communication signal from a desired transmitter, and a controller operative to determine a carrier offset correction based on prior reception of communication signals from the desired transmitter. The receiver chain is operative to generate a carrier offset corrected received signal by applying the carrier offset correction to the received communication signal, and a correlation processor operative to correlate the carrier offset corrected received communication signal with a known sequence.

摘要翻译： 公开了用于减轻接收信号的载波偏移的装置，方法和系统。 接收机的一个实施例包括可操作以从期望的发射机接收通信信号的接收机链路，以及控制器，用于根据来自所需发射机的通信信号的先前接收来确定载波偏移校正。 接收器链可操作以通过对所接收的通信信号应用载波偏移校正来产生载波偏移校正的接收信号，以及相关处理器，用于将载波偏移校正的接收通信信号与已知序列进行相关。

公开(公告)号：US07965787B2

公开(公告)日：2011-06-21

申请号：US12217974

申请日：2008-07-10

申请人： Sujai Chari

发明人： Sujai Chari

IPC分类号： H04B7/02 ,  H04L1/02

CPC分类号： H04L1/0036 ,  H04B1/7156 ,  H04B1/7183 ,  H04B7/084 ,  H04B7/0871 ,  H04B2001/71563 ,  H04L1/06

摘要： Methods and systems of receiving wireless signals are disclosed. One method includes a receiver characterizing signal quality parameters of receive signals for a plurality of receive diversity settings. The receiver selects a first receive diversity setting for synchronizing the receiver with the receive signal based on the characterized signal quality parameters. The receiver selects a second receive diversity setting for receiving data with the receive signal based on the characterized signal quality parameters.

摘要翻译： 公开了接收无线信号的方法和系统。 一种方法包括表征多个接收分集设置的接收信号的信号质量参数的接收机。 接收机基于所表征的信号质量参数选择用于使接收机与接收信号同步的第一接收分集设置。 接收机基于所表征的信号质量参数选择用接收信号接收数据的第二接收分集设置。

公开(公告)号：US07672396B2

公开(公告)日：2010-03-02

申请号：US11472973

申请日：2006-06-22

申请人： Adam L. Schwartz ,  Sujai Chari

发明人： Adam L. Schwartz ,  Sujai Chari

IPC分类号： H04L25/49

CPC分类号： H03D3/009 ,  H03C2200/0058 ,  H04L27/2627 ,  H04L27/364

摘要： Methods of reducing spectral leakage due to I-Q imbalance within a transmitter are disclosed. The method includes the transmitter receiving a data stream of coefficients of a multi-carrier modulation signal. The data stream is pre-processed by processing a set of the coefficients that correspond with selected notch frequencies to reduce the effects of I-Q imbalance of the transmitter, wherein at least a portion of the set of coefficients corresponds to non-symmetrical notch frequencies. The pre-processed data stream is multi-carrier modulated. The multi-carrier modulated pre-processed data stream is I-Q modulated before transmission.

摘要翻译： 公开了减少由于发射机内的I-Q不平衡引起的频谱泄漏的方法。 该方法包括发射机接收多载波调制信号的系数的数据流。 通过处理与所选择的陷波频率相对应的一组系数来预处理数据流，以减少发射机的I-Q不平衡的影响，其中该组系数的至少一部分对应于非对称陷波频率。 预处理的数据流是多载波调制的。 多载波调制预处理数据流在传输之前进行I-Q调制。