公开(公告)号：US20090310658A1

公开(公告)日：2009-12-17

申请号：US12138657

申请日：2008-06-13

Applicant: Rahul Garg ,  Patrick Duvaut ,  Amitkumar Mahadevan ,  Harish Jethanandani

Inventor： Rahul Garg ,  Patrick Duvaut ,  Amitkumar Mahadevan ,  Harish Jethanandani

IPC: H04B1/38

CPC classification number: H04M11/062

Abstract: Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique.

Abstract translation: 用于降低发射机峰值平均比（PAR）的系统和方法可以减少各种模拟组件所需的动态范围。 可以通过应用时域补偿信号来减小PAR，该时域补偿信号在时域补偿信号使用为了减少PAR的目的而被保留的音调的同时减小时域信号中的峰值的幅度。 可以通过改变数字用户线（xDSL）系统中的典型启动过程来实现用于PAR的这些保留音调的预留。 可以使用低复杂度算法或使用自适应技术来实现使用保留的音调来减少PAR。

公开(公告)号：US20090245340A1

公开(公告)日：2009-10-01

申请号：US12412191

申请日：2009-03-26

Applicant: Massimo Sorbara ,  Patrick Duvaut ,  Amitkumar Mahadevan ,  Laurent Francis Alloin

Inventor： Massimo Sorbara ,  Patrick Duvaut ,  Amitkumar Mahadevan ,  Laurent Francis Alloin

IPC: H04B17/00

CPC classification number: H04L1/0045 ,  H04L1/1671 ,  H04L1/243

Abstract: The measurement of far-end crosstalk (FEXT) in a Digital Subscriber Line communications is instrumental in the ability of using a multiple input multiple output (MIMO) pre-coder to cancel FEXT. A reliable robust back channel for transmission of error is instrumental to provide error samples for the proper operation of a MIMO pre-coder. Bins can be dedicated to insure bandwidth from the customer premises equipment (CPE) to the central office (CO). By increasing the margin used in the bins, robustness can be added to this back channel between the CPE and CO.

Abstract translation: 数字用户线路通信中远端串扰（FEXT）的测量有助于使用多输入多输出（MIMO）预编码器取消FEXT。 用于错误传输的可靠的鲁棒后置信道对于为MIMO预编码器的正确操作提供错误样本是有用的。 可以专门用于保护客户端设备（CPE）到中心局（CO）的带宽。 通过增加机箱中使用的余量，可以在CPE和CO之间的后向通道中增加鲁棒性。

公开(公告)号：US20090122855A1

公开(公告)日：2009-05-14

申请号：US12123925

申请日：2008-05-20

Applicant: Patrick Duvaut ,  Amitkumar Mahadevan ,  Pravesh Biyani ,  Shailendra Singh ,  Satyavardhan Maheshwari

Inventor： Patrick Duvaut ,  Amitkumar Mahadevan ,  Pravesh Biyani ,  Shailendra Singh ,  Satyavardhan Maheshwari

IPC: H04L27/01 ,  H04L27/06

CPC classification number: H04L25/03159 ,  H04B3/32 ,  H04L27/2601 ,  H04L2025/03426 ,  H04L2025/03522

Abstract: Systems and methods for mitigating the effects of self-FEXT within an xDSL system are described. At least one embodiment is a method for reducing self-induced far end crosstalk (self-FEXT) in a multiple input multiple output (MIMO) digital subscriber line (xDSL) system. The method comprises deriving an initial value for an off-diagonal multiple input multiple output canceller (ODMC) while the ODMC is inactive and while in data mode. The method further comprises activating the initial ODMC and converging towards an steady-state value for the ODMC by performing an adaptive algorithm to maximize the Shannon's capacity of the system and to reduce upstream self-FEXT. The method also comprises performing bit loading and updating a frequency domain equalizer (FEQ).

Abstract translation: 描述了在xDSL系统中减轻自身FEXT影响的系统和方法。 至少一个实施例是用于减少多输入多输出（MIMO）数字用户线（xDSL）系统中的自感应远端串扰（self-FEXT）的方法。 该方法包括：当ODMC处于非活动状态并处于数据模式时，得到非对角多输入多输出消除器（ODMC）的初始值。 该方法还包括通过执行自适应算法激活初始ODMC并朝向ODMC的稳态值收敛，以使香农的系统容量最大化并减少上游自FEXT。 该方法还包括执行比特加载和更新频域均衡器（FEQ）。

公开(公告)号：US20080298555A1

公开(公告)日：2008-12-04

申请号：US12044443

申请日：2008-03-07

Applicant: Patrick Duvaut ,  Amitkumar Mahadevan ,  Vaibhav Dinesh

Inventor： Patrick Duvaut ,  Amitkumar Mahadevan ,  Vaibhav Dinesh

IPC: H04M3/30

CPC classification number: H04M3/302 ,  H04M3/085

Abstract: Systems and methods for performing loop length estimation are described. One embodiment includes a method which comprises receiving an echo signal for a loop under test where the echo signal is a per-port calibrated echo response obtained using frequency domain reflectometry single-ended line testing (FDR-SELT). The method further comprises analyzing characteristics of the echo signal to perform a loop length estimation based on data relating to ripple frequency as a function of loop length.

Abstract translation: 描述了用于执行环路长度估计的系统和方法。 一个实施例包括一种方法，其包括接收用于测试环路的回波信号，其中回波信号是使用频域反射测量单端线测试（FDR-SELT）获得的每端口校准的回波响应。 该方法还包括分析回波信号的特性，以便根据与纹波频率相关的数据作为循环长度的函数来执行环路长度估计。

公开(公告)号：US20080240368A1

公开(公告)日：2008-10-02

申请号：US12044489

申请日：2008-03-07

Applicant: Patrick Duvaut ,  Amitkumar Mahadevan ,  Vaibhav Dinesh

Inventor： Patrick Duvaut ,  Amitkumar Mahadevan ,  Vaibhav Dinesh

IPC: H04M3/08

CPC classification number: H04M3/302 ,  H04M3/085

Abstract: Systems and methods for performing bridge tap detection are described. One embodiment is a method which comprises receiving an echo signal for a loop under test where the echo signal is a per-port calibrated echo response obtained using frequency domain reflectometry single-ended line testing (FDR-SELT). The method further comprises analyzing the echo signal to determine whether differentiating features are present in the per-port calibrated echo signal in order to determine whether the loop under test is a bridge tapped loop.

Abstract translation: 描述了用于执行桥接抽头检测的系统和方法。 一个实施例是一种方法，其包括接收用于测试环路的回波信号，其中回波信号是使用频域反射测量单端线测试（FDR-SELT）获得的每端口校准的回波响应。 该方法还包括分析回波信号以确定在每端口校准的回波信号中是否存在微分特征，以便确定被测环路是否是桥接抽头循环。

公开(公告)号：US20060193400A1

公开(公告)日：2006-08-31

申请号：US10890134

申请日：2004-07-14

Applicant: Joel Morris ,  Ronald Holzloehner ,  Amitkumar Mahadevan ,  Curtis Menyuk ,  John Zweck

Inventor： Joel Morris ,  Ronald Holzloehner ,  Amitkumar Mahadevan ,  Curtis Menyuk ,  John Zweck

IPC: H04L27/06

CPC classification number: H04L1/203

Abstract: A dual adaptive importance-sampling system and method is provided that can estimate the probability of events by combining dual complementary importance-sampling simulations. The present invention exploits the ability to determine an optimal biased pdf using an iterative procedure that requires relatively little a priori knowledge of how to bias. Hence, the present invention is particularly suited for evaluating the BERs and/or WERs of coded communication and storage systems, and is generally applicable to arbitrarily chosen codes. When applied to coded communication and storage systems, the present invention provides a versatile technique for the fast and accurate estimation of BERs and WERs of FEC codes down to values of 10−20 or lower.

Abstract translation: 提供了一种双重自适应重要性抽样系统和方法，可以通过组合双重互补重要性抽样模拟来估计事件的概率。 本发明利用了使用迭代过程确定最佳偏差pdf的能力，该迭代过程需要相对较少的如何偏向的先验知识。 因此，本发明特别适用于评估编码的通信和存储系统的BER和/或WER，并且通常适用于任意选择的代码。 当应用于编码通信和存储系统时，本发明提供了一种通用技术，用于将FEC码的BER和WER的快速和准确估计降低到10至20或更低的值。

公开(公告)号：US09270831B2

公开(公告)日：2016-02-23

申请号：US13458865

申请日：2012-04-27

Applicant: Amitkumar Mahadevan ,  Kevin D. Fisher ,  Nicholas P. Sands

Inventor： Amitkumar Mahadevan ,  Kevin D. Fisher ,  Nicholas P. Sands

IPC: H04M11/06 ,  H04B3/32

CPC classification number: H04M11/062 ,  H04B3/32

Abstract: Methods, apparatuses (e.g., DSL system hardware, DSL systems, vectoring control entities), techniques, systems, etc. are used for initializing one or more DSL lines joining a vectored DSL line group operating in Showtime. A super-periodic orthogonal pilot sequence from a set of super-periodic orthogonal pilot sequences is assigned to each joining DSL line, wherein each such super-periodic orthogonal pilot sequence in the set has length L and is orthogonal to other sequences in the set over length T. These super-periodic orthogonal pilot sequences are used on the joining DSL lines to generate at least T sync-symbols worth of initialization data, which is processed to generate initialization data and FEXT mitigation coefficients for use when the joining DSL lines become part of the vectored DSL line group.

Abstract translation: 方法，装置（例如，DSL系统硬件，DSL系统，向量控制实体），技术，系统等用于初始化连接在Showtime中操作的向量DSL线路组的一个或多个DSL线路。 从一组超周期正交导频序列的超周期正交导频序列被分配给每个加入DSL线，其中集合中的每个这样的超周期正交导频序列具有长度L，并且与组中的其他序列正交 这些超周期正交导频序列用于加入DSL线路以产生至少T个同步符号的初始化数据，其被处理以产生初始化数据和当加入DSL线路成为部分时使用的FEXT缓解系数 的矢量DSL线组。

公开(公告)号：US08780686B2

公开(公告)日：2014-07-15

申请号：US13189095

申请日：2011-07-22

Applicant: Nicholas P. Sands ,  Stephanie F. Pereira ,  Darren B. Hutchinson ,  Kevin D. Fisher ,  Amitkumar Mahadevan

Inventor： Nicholas P. Sands ,  Stephanie F. Pereira ,  Darren B. Hutchinson ,  Kevin D. Fisher ,  Amitkumar Mahadevan

IPC: H04J1/12 ,  H04B3/20

CPC classification number: H04B3/32

Abstract: The memory storage, transmission and processing demands of a vectored DSL system are reduced by sampling a subset of DSL tones in the DSL tone range used in the vectored system. This data is smoothed (denoised) to further reduce the data's size, sacrificing some fidelity or precision as a result. Finally, lossless entropy coding or the like is performed to encode the FEXT cancellation data for storage and use. The resulting data is less likely to cause transmission bottlenecks in the vectored system, can be stored and used more efficiently for both on-chip and off-chip vectoring implementations, and can be readily updated in various ways.

Abstract translation: 矢量DSL系统的存储器存储，传输和处理需求通过在矢量系统中使用的DSL音调范围中采样DSL音调的子集来减少。 该数据被平滑（去噪），以进一步减少数据的大小，从而牺牲一些保真度或精度。 最后，执行无损熵编码等以对用于存储和使用的FEXT取消数据进行编码。 所得到的数据不太可能导致向量系统中的传输瓶颈，可以在片上和片外向量实现方面更有效地存储和使用，并且可以以各种方式容易地更新。

公开(公告)号：US08213536B2

公开(公告)日：2012-07-03

申请号：US12138813

申请日：2008-06-13

Applicant: Harish Jethanandani ,  Rahul Garg ,  Patrick Duvaut ,  Amitkumar Mahadevan

Inventor： Harish Jethanandani ,  Rahul Garg ,  Patrick Duvaut ,  Amitkumar Mahadevan

IPC: H04L25/49 ,  H04L23/00 ,  H04B1/38

CPC classification number: H04L27/2618

Abstract: Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique.

Abstract translation: 用于降低发射机峰值平均比（PAR）的系统和方法可以减少各种模拟组件所需的动态范围。 可以通过应用时域补偿信号来减小PAR，该时域补偿信号在时域补偿信号使用为了减少PAR的目的而被保留的音调的同时减小时域信号中的峰值的幅度。 可以通过改变数字用户线（xDSL）系统中的典型启动过程来实现用于PAR的这些保留音调的预留。 可以使用低复杂度算法或使用自适应技术来实现使用保留的音调来减少PAR。

公开(公告)号：US08204211B2

公开(公告)日：2012-06-19

申请号：US12431878

申请日：2009-04-29

Applicant: Amitkumar Mahadevan ,  Patrick Duvaut ,  Laurent Francis Alloin

Inventor： Amitkumar Mahadevan ,  Patrick Duvaut ,  Laurent Francis Alloin

IPC: H04M1/00 ,  H04M9/00 ,  H04M1/76

CPC classification number: H04B3/32

Abstract: Systems and methods are described for selecting tones for far-end crosstalk (FEXT) mitigation. In particular, systems and methods are described for performing far-end crosstalk (FEXT) mitigation within a digital subscriber line (xDSL) system. One embodiment is a method that comprises determining a first set of function values relating to a per-tone signal-to-noise ratio (SNR) for a user among a plurality of users for a number of tones, wherein the number of tones is less than or equal to a total number of tones available for transmission. The method further comprises estimating coefficients for performing FEXT mitigation for the number of tones, performing FEXT mitigation on the number of tones based on the estimated coefficients, and performing FEXT mitigation on a selected group of tones from among the number of tones, wherein the selected group of tones is less than or equal to the number tones.

Abstract translation: 描述了用于选择用于远端串扰（FEXT）减轻的音调的系统和方法。 特别地，描述了用于在数字用户线（xDSL）系统内执行远端串扰（FEXT）减轻的系统和方法。 一个实施例是一种方法，其包括确定与多个用户之间的用户对于多个音调的用户的每音调信噪比（SNR）有关的第一功能值集合，其中，音调数量较少 超过或等于可用于传输的总音数。 该方法还包括估计用于对音调数执行FEXT减轻的系数，基于估计的系数对音调数执行FEXT减轻，以及从所选择的音数中对所选择的音调组执行FEXT减轻，其中所选择的 一组音调小于或等于数字音。