公开(公告)号：US06996230B1

公开(公告)日：2006-02-07

申请号：US10460968

申请日：2003-06-13

申请人： Fred T. Chu ,  Michael D. Turner ,  Ayman K. Ghobrial

发明人： Fred T. Chu ,  Michael D. Turner ,  Ayman K. Ghobrial

IPC分类号： H04B3/23

CPC分类号： H04B3/23

摘要： An echo canceler for a fractionally spaced telecommunication receiver employs a signal estimator, which generates a fractionally spaced representation of a received information signal that has been subjected to Tomlinson preceding. The output of the signal estimator is differentially combined with fractionally spaced outputs of the echo canceller, so as to effectively remove the contribution of the received information signal from the echo cancellation update operation. As a result, the echo update signal will consist primarily of the residual echo and the noise from the wireline/loop. The error signal can be used at the fractional spacing rate to update all of the echo canceler coefficients, largely without interference from the much larger received information signal. This allows a higher echo canceler gain than that currently incorporated into HDSL2 echo canceler updates.

摘要翻译： 用于分数间隔的电信接收机的回波消除器采用信号估计器，其产生已经经受Tomlinson预编码的接收信息信号的分数间隔表示。 信号估计器的输出与回波消除器的分数间隔的输出差分地组合，以便有效地消除所接收的信息信号对回波消除更新操作的贡献。 结果，回波更新信号将主要由剩余回声和来自有线/回路的噪声组成。 可以以分数间隔速率使用误差信号来更新所有回波消除器系数，而不受来自较大接收信息信号的干扰。 这允许比当前并入HDSL2回波消除器更新中更高的回波消除器增益。

公开(公告)号：US06990109B2

公开(公告)日：2006-01-24

申请号：US09999463

申请日：2001-10-31

申请人： Bruce Edward Mitchell ,  Ayman K. Ghobrial

发明人： Bruce Edward Mitchell ,  Ayman K. Ghobrial

IPC分类号： H04L12/28 ,  H04L7/00 ,  H04J3/06

CPC分类号： H04L12/5601 ,  H04L2012/5616 ,  H04L2012/5656 ,  H04L2012/5671

摘要： Adaptive clock recovery for the receiving entity of a communication system transporting constant bit-rate (CBR) services over an asynchronous transfer mode (ATM) or ATM-like network is performed by a digital phase locked loop (DPLL). The recovered clock is based on the DPLL's phase detector's count of high frequency service clock cycles between transitions in an input signal representative of instances of receipt of ATM cells subject to cell delay variations through the network, and a reference clock signal whose frequency is a prescribed fraction of that of the output clock. The DPLL's VCO function is an increment/decrement of the service clock frequency, which avoids constraining the operation of a high performance modem (such as a V.90 modem).

公开(公告)号：US06438156B1

公开(公告)日：2002-08-20

申请号：US09248664

申请日：1999-02-11

申请人： Ayman K. Ghobrial ,  Steven R. Blackwell

发明人： Ayman K. Ghobrial ,  Steven R. Blackwell

IPC分类号： H04L2701

CPC分类号： H04L25/03038 ,  H04L2025/03375 ,  H04L2025/03477 ,  H04L2025/03617

摘要： A distortion compensation filtering mechanism for a direct spread-spectrum radio receiver comprises an iteratively adaptive FIR filter installed in the received signal processing path of the radio just upstream of the despreading function. The filter may be implemented as a relatively small numbered tap filter, having its precursor tap fixed at a maximum value. The remaining filter tap values are individually adaptively adjusted by the radio's control processor, which executes a tap adjustment routine to iteratively increment or decrement each variable tap value of the FIR filter to an ‘optimized’ value, that effectively minimizes the total (I and Q) power in the error in the data decisions performed by data signal analyzer.

摘要翻译： 用于直接扩频无线电接收机的失真补偿滤波机构包括安装在解扩功能上游的无线电接收信号处理路径中的迭代自适应FIR滤波器。 滤波器可以被实现为相对小的编号的抽头滤波器，其前体抽头固定在最大值。 剩余的滤波器抽头值通过无线电的控制处理器单独地自适应地调整，无线电的控制处理器执行抽头调整例程，以将FIR滤波器的每个可变抽头值迭加地递减或递减到“优化”值，其有效地最小化总计（I和Q ）功率由数据信号分析仪执行的数据决策中的误差。