公开(公告)号：US10057428B1

公开(公告)日：2018-08-21

申请号：US15708654

申请日：2017-09-19

Applicant: 8x8, Inc.

Inventor： Marc Petit-Huguenin ,  Garth Judge

IPC: H04L12/66 ,  H04L12/26 ,  H04L29/06 ,  H04L27/00 ,  H04M7/00 ,  H04M15/00

CPC classification number: H04M7/0084 ,  H04L12/66 ,  H04L43/00 ,  H04L43/0823 ,  H04L43/50 ,  H04L65/1006 ,  H04L2027/0075 ,  H04M7/0069 ,  H04M15/56

Abstract: A variety of methods, systems, devices and arrangements are implemented for assessing and/or controlling call routing for VoIP/VioIP calls. According to one such method, endpoint devices are used to monitor and/or assess the call-quality. The assessment is sent to a centralized server arrangement and call-routing is controlled therefrom. Endpoint devices employ a decentralized testing mechanism to further monitor and assess call quality including the use of test connections. Aspects of call quality are analyzed and attributed to endpoint devices and/or local connections or networks to distinguish intermediate routing issues from local/endpoint issues.

公开(公告)号：US09800451B2

公开(公告)日：2017-10-24

申请号：US15207085

申请日：2016-07-11

Applicant: Maxlinear, Inc.

Inventor： Curtis Ling ,  Timothy Gallagher

IPC: H04L27/26 ,  H04L1/20 ,  H04L25/02 ,  H04L27/00

CPC classification number: H04L27/2649 ,  H04L1/20 ,  H04L25/0204 ,  H04L27/2627 ,  H04L27/2659 ,  H04L27/266 ,  H04L27/2695 ,  H04L2027/003 ,  H04L2027/0038 ,  H04L2027/0067 ,  H04L2027/0075

Abstract: Methods and apparatus for processing multichannel signals in a multichannel receiver are described. In one implementation, a plurality of demodulator circuits may provide a plurality of outputs to a processing module, with the processing module then simultaneously estimating noise characteristics based on the plurality of outputs and generating a common noise estimate based on the plurality of outputs. This common noise estimate may then be provided back the demodulators and used to adjust the demodulation of signals in the plurality of demodulators to improve phase noise performance.

公开(公告)号：US20030128660A1

公开(公告)日：2003-07-10

申请号：US10331904

申请日：2002-12-31

Inventor： Atsushi Ito ,  Tomohiro Kimura ,  Masahiro Ishii

IPC: G01R031/08

CPC classification number: H04L27/2657 ,  H04L27/2675 ,  H04L2027/0028 ,  H04L2027/0055 ,  H04L2027/0075 ,  H04L2027/0091

Abstract: An object of the present invention is provide an OFDM communications apparatus for achieving a phase correcting a highly-accurate phase correcting process which does not gradually lose accuracyor requiring large hardware. An Arctan vector phase rotator 104 calculates a phase of a vector signal. A phase correction information estimator 105 finds an estimated multipath-fading deviation value from the phase of a vector in a phase error estimation symbol 207, and also finds an estimated non-multipath-fading deviation value from the phase of a vector in a pilot signal 209. An adder 106 adds these two estimated deviation values together for output as a total phase correction value. Based on the total phase correction value, the Arctan vector phase rotator 104 rotates the phase of a vector to be demodulated for phase correction.

Abstract translation: 本发明的目的是提供一种OFDM通信装置，用于实现相位校正高精度相位校正处理，该处理不会逐渐失去要求较大硬件的精度。 Arctan矢量相位旋转器104计算矢量信号的相位。 相位校正信息估计器105从相位误差估计符号207中的向量的相位中求出估计的多径衰落偏差值，并且还从导频信号中的向量的相位求出估计的非多径衰落偏差值 加法器106将这两个估计偏差值相加在一起作为总相位校正值输出。 基于总相位校正值，Arctan矢量相位旋转器104使要解调的矢量的相位旋转以进行相位校正。

公开(公告)号：US3638125A

公开(公告)日：1972-01-25

申请号：US3638125D

申请日：1969-11-26

Applicant: BELL TELEPHONE LABOR INC

Inventor： GOELL JAMES E

IPC: H04L27/00 ,  H04L27/18 ,  H04L27/227 ,  H04B1/30

CPC classification number: H04L27/2273 ,  H04L2027/0067 ,  H04L2027/0075

Abstract: In a synchronous detector the carrier of a binary differentially coherent phase shift-keyed signal is recovered by decomposing the carrier information signal into its conjugate in-phase and outof-phase components which contain in their arguments a term delta (t) representing the phase difference between the carrier and a local oscillator signal. The conjugate components are multiplied to generate a product signal which is sampled every other time slot to produce an error signal proportional to sin(2 delta (t)). This signal is applied to the local oscillator to phase lock the local oscillator signal to the carrier of the information signal.

Abstract translation: 在同步检测器中，通过将载波信息信号分解成其共轭同相和异相分量来恢复二进制差分相干相移键控信号的载波，其中包含在它们的参数中的术语delta（t） 载波和本地振荡器信号之间的相位差。 将共轭分量相乘以产生每隔一个时隙采样的乘积信号，以产生与sin [2δ（t）]成比例的误差信号。 该信号被施加到本地振荡器以将本地振荡器信号锁定到信息信号的载波。

公开(公告)号：US20180123840A1

公开(公告)日：2018-05-03

申请号：US15796596

申请日：2017-10-27

Applicant: Mentor Graphics Corporation

Inventor： Vladimir B. Dmitriev-Zdorov

IPC: H04L25/49 ,  H04L27/00

CPC classification number: H04L25/4917 ,  H04L27/0014 ,  H04L2027/0075

Abstract: This application discloses a computing system to perform a fast evaluation of a worst case eye diagram for a channel capable of communicating signals encoding data in more than two value levels. The computing system can identify multiple step responses of the channel, each corresponding to a transition between a plurality of the value levels. The computing system can determine distribution boundaries of the signals at each of the value levels based, at least in part, on the step responses of the channel. The computing system can utilize the distribution boundaries at the value levels to determine boundaries of eye openings between adjacent value levels or to build worst case input patterns used to generate the worst case eye diagram for the channel. The computing system can predict a signal integrity of the channel based on the distribution boundaries at each of the value levels.

公开(公告)号：US20120087449A1

公开(公告)日：2012-04-12

申请号：US12979270

申请日：2010-12-27

Applicant: CURTIS LING ,  TIMOTHY GALLAGHER

Inventor： CURTIS LING ,  TIMOTHY GALLAGHER

IPC: H04L25/08

CPC classification number: H04L27/2649 ,  H04L1/20 ,  H04L25/0204 ,  H04L27/2627 ,  H04L27/2659 ,  H04L27/266 ,  H04L27/2695 ,  H04L2027/003 ,  H04L2027/0038 ,  H04L2027/0067 ,  H04L2027/0075

Abstract: Methods and apparatus for processing multichannel signals in a multichannel receiver are described. In one implementation, a plurality of demodulator circuits may provide a plurality of outputs to a processing module, with the processing module then simultaneously estimating noise characteristics based on the plurality of outputs and generating a common noise estimate based on the plurality of outputs. This common noise estimate may then be provided back the demodulators and used to adjust the demodulation of signals in the plurality of demodulators to improve phase noise performance.

Abstract translation: 描述了在多通道接收机中处理多信道信号的方法和装置。 在一个实现中，多个解调器电路可以向处理模块提供多个输出，处理模块然后基于多个输出同时估计噪声特性，并且基于多个输出生成公共噪声估计。 然后，可以将这种公共噪声估计提供给解调器，并用于调整多个解调器中的信号的解调以改善相位噪声性能。

公开(公告)号：US20070230637A1

公开(公告)日：2007-10-04

申请号：US11632136

申请日：2004-07-15

Applicant: Joshua Koslov

Inventor： Joshua Koslov

IPC: H04L27/06

CPC classification number: H04L27/0014 ,  H04L2027/003 ,  H04L2027/0053 ,  H04L2027/0067 ,  H04L2027/0075

Abstract: A system and method for carrier recovery includes a plurality of carrier recovery modules, each processing the same input symbols, and each having a gain input and an error output. A loop gain control receives errors from the carrier recovery modules and provides gains to the carrier recovery modules. Based upon the errors during a current period, the loop gain control determines which module produced lowest errors, and selects the gain associated with that module as a best gain which is applied to a module which outputs symbols for decoding during a next period.

Abstract translation: 用于载波恢复的系统和方法包括多个载波恢复模块，每个载波恢复模块处理相同的输入符号，并且每个具有增益输入和误差输出。 环路增益控制从载波恢复模块接收错误，并向载波恢复模块提供增益。 基于当前周期中的错误，环路增益控制确定哪个模块产生最低误差，并且选择与该模块相关联的增益作为最佳增益，该最佳增益被应用于在下一个周期内输出用于解码的符号的模块。

公开(公告)号：US07139340B2

公开(公告)日：2006-11-21

申请号：US10185971

申请日：2002-06-28

Applicant: Carl G. Scarpa

Inventor： Carl G. Scarpa

IPC: H04L27/06

CPC classification number: H04L27/266 ,  H04L27/2659 ,  H04L27/2675 ,  H04L27/2679 ,  H04L2027/0028 ,  H04L2027/0075 ,  H04L2027/0095

Abstract: Methods and apparatus for estimating and correcting carrier frequency offsets in a bust multi-tone receiver are described. Course and fine carrier frequency estimates are generated from the signal's preamble. Decision directed carrier frequency offset estimates are then generated from the signal field and data fields of the multi-tone signal. Frequency error estimates are generated for each tone of the signal and combined using a weighted average to generate the frequency error estimate used to perform the correction operation. Error estimates corresponding to noisy data tones are weighted less then estimates corresponding to less noisy data tones. In cases of low SNR frequency error estimates corresponding to pilots are weighted by an extra amount as compared to error estimates corresponding to tones used to transmit data symbols. During times of high SNR error estimates corresponding to pilot tones are weighted in the same manner as error estimates corresponding to data tones.

Abstract translation: 描述了用于估计和校正胸围多音调接收机中的载波频率偏移的方法和装置。 从信号的前导码生成课程和精细载波频率估计。 然后根据多音调信号的信号场和数据场产生决策导向载波频率偏移估计。 针对信号的每个音调产生频率误差估计，并使用加权平均值组合以产生用于执行校正操作的频率误差估计。 与噪声数据音调相对应的误差估计被加权小于对应于较少嘈杂数据音调的估计。 在低SNR的情况下，与对应于用于发送数据符号的音调的误差估计值相比，对应于导频的估计值加权额外的量。 在高SNR的时间期间，对应于导频音调的误差估计以与对应于数据音调的误差估计相同的方式进行加权。

公开(公告)号：US06728301B1

公开(公告)日：2004-04-27

申请号：US09612536

申请日：2000-07-07

Applicant: George Chrisikos

Inventor： George Chrisikos

IPC: H04B169

CPC classification number: H04B1/7087 ,  H04B1/7115 ,  H04B2201/70701 ,  H04L2027/0055 ,  H04L2027/0075

Abstract: A method is providing for calculating local oscillator phase errors in a code division multiple access (CDMA) receiver using an arctangent calculation of the difference vectors between sample stream (multipath) delays. Instead of the conventional cross-product calculation of pilot symbols, a phase correction, using both real and imaginary parts of the complex conjugate, is preformed in each sample stream delay path before the step of maximal-ratio combining (MRC). The weighted combination is then selectively filtered and accumulated, depending on whether the automatic frequency control (AFC) loop is tracking or acquiring. Then, an arctangent polynomial approximation is used to find the actual phase error. An AFC system using the above-mentioned MRC combination and arctangent calculation of phase error is also provided.

Abstract translation: 一种方法是使用采样流（多径）延迟之间的差矢量的反正切计算来计算码分多址（CDMA）接收机中的本地振荡器相位误差。 代替导频符号的常规交叉乘积计算，在最大比组合（MRC）的步长之前，在每个采样流延迟路径中执行使用复共轭的实部和虚部的相位校正。 然后根据自动频率控制（AFC）循环是跟踪还是获取，选择性地过滤和累加加权组合。 然后，使用反正切多项式近似来找到实际的相位误差。 还提供了使用上述MRC组合的AFC系统和相位误差的反正切计算。

公开(公告)号：US3189826A

公开(公告)日：1965-06-15

申请号：US2766560

申请日：1960-05-09

Applicant: GEN ELECTRIC

Inventor： MITCHELL EDWARD E ,  PERRY JR ALBERT D

IPC: H04L27/00 ,  H04L27/227

CPC classification number: H04L27/2273 ,  H04L2027/0028 ,  H04L2027/0059 ,  H04L2027/0067 ,  H04L2027/0075