Monitoring phase non-linearities in an optical communications system
    1.
    发明授权
    Monitoring phase non-linearities in an optical communications system 失效
    监测光通信系统中的相位非线性

    公开(公告)号:US08594499B1

    公开(公告)日:2013-11-26

    申请号:US10389804

    申请日:2003-03-18

    IPC分类号: H04B10/071

    CPC分类号: H04B10/073

    摘要: Phase nonlinearities of an optical communications system are monitored by generating a test signal which includes a predetermined property that is uniquely associated with at least one phase nonlinearity of the optical communications system. The predetermined property of the test signal is then detected at a monitoring point of the optical communications system, and used to estimate the associated phase nonlinearity.

    摘要翻译: 通过生成包括与光通信系统的至少一个相位非线性唯一相关联的预定属性的测试信号来监视光通信系统的相位非线性。 然后在光通信系统的监视点检测测试信号的预定属性,并用于估计相关的相位非线性。

    High speed digital to analog converter
    2.
    发明授权
    High speed digital to analog converter 有权
    高速数模转换器

    公开(公告)号:US06781537B1

    公开(公告)日:2004-08-24

    申请号:US10457528

    申请日:2003-06-10

    IPC分类号: H03M166

    CPC分类号: H03M1/0836 H03M1/74

    摘要: A high speed D/A converter includes a phase aligner, and a vector summation block. The phase aligner operates to ensure precise phase alignment between corresponding bits of a parallel N-bit digital signal having a data rate of at least 2 GHz. The vector addition block performs a vector addition of the phase-aligned bits of the parallel N-bit digital signal. Each bit of the parallel N-bit digital signal can be weighted to ensure a correct additive contribution to the analog signal level appearing at the output of the D/A converter. Vector addition of the weighted bits can be accomplished using a microwave signal combiner network in the form of either a multistage parallel cascade of impedance matched junctions, or a linear cascade of junctions.

    摘要翻译: 高速D / A转换器包括相位对准器和矢量求和块。 相位对准器操作以确保具有至少2GHz的数据速率的并行N位数字信号的相应位之间的精确相位对准。 矢量相加块执行并行N位数字信号的相位比特位的向量相加。 并行N位数字信号的每一位可被加权,以确保对D / A转换器输出端出现的模拟信号电平的正确附加贡献。 加权比特的向量加法可以使用以阻抗匹配连接的多级并联级联或连接的线性级联的形式的微波信号组合器网络来实现。

    Decorrelation of WDM signals
    3.
    发明授权
    Decorrelation of WDM signals 有权
    WDM信号的相关性

    公开(公告)号:US07155128B2

    公开(公告)日:2006-12-26

    申请号:US10014353

    申请日:2001-12-14

    IPC分类号: H04J14/02

    CPC分类号: H04B10/2563 H04J14/02

    摘要: A method and system for reducing non-linear signal degradation effects of WDM optical signals exacerbated by highly correlated bit patterns of optical waveforms in neighboring optical channels. Embodiments include offsetting the transmission times of signals in neighboring channels, and applying different scrambling patterns to the respective data streams prior to transmission on neighboring optical channels.

    摘要翻译: 一种用于减少WDM光信号的非线性信号劣化效应的方法和系统,其由相邻光信道中的光波形的高度相关位模式加剧。 实施例包括抵消相邻信道中的信号的传输时间,以及在相邻光信道上传输之前将各种数据流应用不同的加扰模式。

    Methods of and apparatus for optical signal transmission
    4.
    发明授权
    Methods of and apparatus for optical signal transmission 失效
    光信号传输的方法和装置

    公开(公告)号:US06473214B1

    公开(公告)日:2002-10-29

    申请号:US09283213

    申请日:1999-04-01

    IPC分类号: H04B1004

    CPC分类号: H04L5/06 H04L25/497 H04L27/02

    摘要: A binary signal is encoded to produce a three-level encoded signal having reduced bandwidth and small low frequency and d.c. components, e.g. using modified duobinary encoding, the encoded signal directly modulating a semiconductor laser to produce a frequency modulated optical signal, which is passed through an interference filter to provide two-state amplitude modulation from the three-state frequency modulation for direct recovery of the binary signal by an optical receiver, the interference filter providing constructive and destructive interference for frequencies corresponding to binary one and zero bits respectively. An array transmission system can be provided by combining multiple such frequency modulated optical signals, from multiple lasers with respective central frequencies and respective encoders for multiple binary signals, using an array waveguide which also serves as a channel frequency filter, with a single interference filter. Polarization modulation instead of frequency modulation, and external modulation of an optical signal from an optical source, are also described.

    摘要翻译: 二进制信号被编码以产生具有减小的带宽和小的低频和直流的三电平编码信号。 组分,例如 使用修改的二进制编码,编码信号直接调制半导体激光器以产生调频光信号,该信号通过干涉滤波器从三态调制提供双态幅度调制,以通过以下方式直接恢复二进制信号: 光接收机,干扰滤波器分别为对应于二进制1和零位的频率提供建设性和相消干扰。 可以通过使用具有单个干涉滤波器的阵列波导来组合来自具有各自中心频率的多个激光器和多个二进制信号的相应编码器的多个这种频率调制光信号来提供阵列传输系统。 还描述了偏振调制而不是频率调制,以及来自光源的光信号的外部调制。

    Electrical domain compensation of non-linear effects in an optical communications system
    5.
    发明授权
    Electrical domain compensation of non-linear effects in an optical communications system 有权
    光通信系统中非线性效应的电域补偿

    公开(公告)号:US07756421B2

    公开(公告)日:2010-07-13

    申请号:US10405236

    申请日:2003-04-03

    IPC分类号: H04B10/00

    CPC分类号: H04B10/2543

    摘要: Nonlinearity-induced signal distortions are compensated by processing an input communications signal, in the electrical domain prior to Electrical-to-optical conversion and transmission through an optical link of a communications system. According to the invention, a compensation operator is determined that substantially mitigates the nonlinearity-induced signal distortions imparted to an optical signal traversing the communications system. The input communications signal is then input to the compensation operator to generate a predistorted electrical signal. This predistorted electrical signal is then used to modulate an optical source to generate a corresponding predistorted optical signal for transmission through the optical communications system. With this arrangement, arbitrary nonlinearity-induced signal distortions imparted by the optical link can be compensated in such a manner that a comparatively undistorted optical signal is obtained at the receiving end of the optical link.

    摘要翻译: 在通过通信系统的光链路的电 - 光转换和传输之前,通过处理电域中的输入通信信号来补偿非线性引起的信号失真。 根据本发明,确定补偿算子,其基本上减轻施加到穿过通信系统的光信号的非线性引起的信号失真。 然后将输入通信信号输入到补偿操作器以产生预失真的电信号。 然后,该预失真的电信号用于调制光源以产生用于通过光通信系统传输的相应的预失真光信号。 通过这种布置,可以以在光链路的接收端获得相对不失真的光信号的方式来补偿由光链路赋予的任意非线性引起的信号失真。

    Broadband control of polarization mode dispersion
    7.
    发明授权
    Broadband control of polarization mode dispersion 失效
    宽带控制偏振模色散

    公开(公告)号:US07352971B2

    公开(公告)日:2008-04-01

    申请号:US10209904

    申请日:2002-08-02

    IPC分类号: H04B10/12

    CPC分类号: H04B10/2569

    摘要: A method and system is provided for compensating polarization mode dispersion (PMD) in an optical communications system includes a controller designed to control a broadband PMD compensator to differentially delay light at each one of a plurality of selected wavelengths. At least one of the selected wavelengths lies between an adjacent pair of channel wavelengths of the optical communications system. A performance parameter value indicative of PMD is measured at each channel wavelength of the optical communications system. An estimated performance parameter value is then calculated at each selected wavelength, and an error function calculated as a function of wavelength based on the estimated performance parameter values. The broadband PMD compensator is then controlled to minimize the value of the error function.

    摘要翻译: 提供了一种用于补偿光通信系统中的偏振模色散(PMD)的方法和系统,包括设计成控制宽带PMD补偿器差分延迟多个选定波长中的每一个处的光的控制器。 所选择的波长中的至少一个位于光通信系统的相邻的一对通道波长之间。 在光通信系统的每个信道波长处测量指示PMD的性能参数值。 然后在每个选择的波长处计算估计的性能参数值,并且基于估计的性能参数值计算作为波长的函数的误差函数。 然后控制宽带PMD补偿器以最小化误差函数的值。

    Optimization of a communications system based on identification of an optical medium
    8.
    发明授权
    Optimization of a communications system based on identification of an optical medium 有权
    基于光学介质识别的通信系统的优化

    公开(公告)号:US06687464B1

    公开(公告)日:2004-02-03

    申请号:US09481691

    申请日:2000-01-12

    IPC分类号: H04B1008

    CPC分类号: H04B10/2503 H04B10/079

    摘要: An optical communications system is adapted for connection to an optical fiber link of an optical communications network. The system obtains a fiber identifier respecting the optical fiber link; a respective optimum setting of one or more parameters of the optical communications system; and adjusts a respective value of each parameter in accordance with the respective optimum setting. The fiber identifier can be obtained from a value of at least one fiber transmission property of the optical fiber link. The fiber transmission property value is used to search a look-up table of class definitions, each class definition including a respective class identifier and at least one corresponding characteristic transmission property value. A class identifier is selected as the fiber identifier from the class definition for which each characteristic transmission property value most closely matches a corresponding fiber transmission property value. Each class definition may also include an optimum setting for each parameter.

    摘要翻译: 光通信系统适于连接到光通信网络的光纤链路。 该系统获得关于光纤链路的光纤标识符; 光通信系统的一个或多个参数的相应最佳设置; 并根据各自的最佳设定调整各参数的相应值。 可以从光纤链路的至少一个光纤传输特性的值获得光纤标识符。 光纤传输属性值用于搜索类定义的查找表,每个类定义包括相应的类标识符和至少一个对应的特征传输属性值。 从类别定义中选择类别标识符作为每个特征传输特性值与其对应的光纤传输属性值最匹配的类定义。 每个类定义也可以包括每个参数的最佳设置。

    Approximation of recursive least squares equalization

    公开(公告)号:US11239929B1

    公开(公告)日:2022-02-01

    申请号:US17203332

    申请日:2021-03-16

    IPC分类号: H04B3/46 H04B17/318

    摘要: A receiver is configured to detect, at a communication interface, a received signal that suffers from degradations incurred over a communication channel. The receiver applies an adaptive filter to a series of received blocks of a digital representation of the received signal, thereby generating respective filtered blocks, where each received block represents 2N frequency bins, and where N is a positive integer. The receiver calculates coefficients for use by the adaptive filter on a jth received block as a function of (i) error estimates associated with an (j−D−1)th filtered block, where D is a positive integer representing a number of blocks, and where j is a positive integer greater than (D−1); and (ii) an inverse of an approximate covariance matrix associated with the (j−D−1)th received block, where the approximate covariance matrix is a diagonal matrix of size L×L, and where L is a positive integer lower than 2N.