Error filtering in a hybrid equalizer system
    1.
    发明授权
    Error filtering in a hybrid equalizer system 失效
    混合均衡器系统中的错误过滤

    公开(公告)号:US06285709B1

    公开(公告)日:2001-09-04

    申请号:US08962204

    申请日:1997-10-31

    IPC分类号: H03H740

    CPC分类号: H04L25/4927 H04L25/03057

    摘要: Apparatus and methods of compensating for distortions introduced in communication signals received over a telephone network. An adaptive linear equalizer (LE) pre-filter is used for filtering incoming sampled communication signals received via the telephone network transmission medium. An adaptive decision feedback equalizer (DFE) is used in conjunction with the LE to provide error filtering as a hybrid equalizer system to determine which of a plurality of communication states of the sampled communication signals as an accurate estimate of the originally transmitted signals over the transmission medium, responsive to the filtered communication signals from the LE. An error signal is generated relative to the difference between the determined states of the decision mechanism of the DFE and the filtered communication signals from the LE. Further, an error filter provides a filtered output of the generated error signal, wherein the error filter has an error filter characteristic defined in accordance with the known telephone network transmission medium. The LE for the received sampled communication signals has a LE pre-filter characteristic defined in accordance with the filtered output of the error filter, using a recursive least-mean-square (LMS) technique.

    摘要翻译: 补偿在通过电话网络接收的通信信号中引入的失真的装置和方法。 自适应线性均衡器(LE)预滤波器用于滤波经由电话网络传输介质接收的输入采样通信信号。 自适应判决反馈均衡器(DFE)与LE结合使用,以提供作为混合均衡器系统的错误滤波,以确定采样的通信信号的多个通信状态中的哪一个作为传输上原始传输的信号的精确估计 介质,响应来自LE的滤波后的通信信号。 相对于DFE的判定机构的确定状态与来自LE的滤波后的通信信号之间的差异产生误差信号。 此外,误差滤波器提供产生的误差信号的滤波输出,其中误差滤波器具有根据已知的电话网络传输介质定义的误差滤波特性。 所接收的采样通信信号的LE具有使用递归最小均方(LMS)技术根据误差滤波器的滤波输出定义的LE预滤波特性。

    Compensation method for I/Q channel imbalance errors
    2.
    发明授权
    Compensation method for I/Q channel imbalance errors 失效
    I / Q通道不平衡误差补偿方法

    公开(公告)号:US5705949A

    公开(公告)日:1998-01-06

    申请号:US712927

    申请日:1996-09-13

    IPC分类号: H03D3/00 H04L27/00

    摘要: A method in which correctable I/Q imbalance errors in a complex receiver can be detected and compensated for digitally without the use of special calibration signals. Differential D.C. offset errors are compensated by averaging the incoming I.sub.d and Q.sub.d digital signals and subtracting from them an expected value of differential D.C. offset, for example, computed from the long term average of the I and Q signals to create I' and Q' signals. Differential gain imbalance errors are corrected by calculating a root means square average of the I' and Q' digital signals and applies to them compensation coefficients K.sub.x and K.sub.y determined from either the RMS average or from a Stochastic Gradient Algorithm. The DSP compensates for the quadrature phase errors by calculating a compensation matrix which is independent of the frequency of the carrier and applies the compensation matrix to the I' and Q' digital signals. The compensation matrix for quadrature phase errors is completely independent of the frequency of the input carrier signal supplied to the complex receiver, and is not dependent on the use of a calibration signal. The compensation may be performed as a step in calibration of the complex receiver, or continuously.

    摘要翻译: 可以在不使用特殊校准信号的情况下数字地检测和补偿复数接收机中的可校正I / Q不平衡误差的方法。 通过平均输入的Id和Qd数字信号并从其中减去差分DC偏移的期望值,例如从I和Q信号的长期平均值计算以产生I'和Q'信号来补偿差分DC偏移误差 。 通过计算I'和Q'数字信号的均方根平均值来校正差分增益不平衡误差,并应用于从RMS平均值或随机梯度算法确定的补偿系数Kx和Ky。 DSP通过计算与载波频率无关的补偿矩阵来补偿正交相位误差,并将补偿矩阵应用于I'和Q'数字信号。 正交相位误差的补偿矩阵完全独立于提供给复合接收机的输入载波信号的频率,而不依赖于校准信号的使用。 补偿可以作为复合接收机的校准步骤,或连续地进行。

    Method and apparatus for generating a probing signal for a system having non-linear network and codec distortion
    3.
    发明授权
    Method and apparatus for generating a probing signal for a system having non-linear network and codec distortion 有权
    用于产生具有非线性网络和编解码器失真的系统的探测信号的方法和装置

    公开(公告)号:US06256353B1

    公开(公告)日:2001-07-03

    申请号:US09421955

    申请日:1999-10-19

    IPC分类号: H04B1404

    摘要: The present invention provides a method of generating a signal that may be used to determine the characteristic response of a communication channel that utilizes the public Digital Telephone Network (DTN). The channel includes the DTN, which may have Network Digital Attenuators (NDA) and/or Robbed Bit Signalling (RBS), and a Digital-to-Analog Converter (DAC), (also known as a codec), as well as the analog characteristics of the local loop, typically a twisted pair of copper wires. The present invention provides a method and apparatus to determine the optimal sampling instant of the received data stream. The present invention provides a probing signal that is well-suited for use in determining the channel's response to a known sequence of PCM codes used as data symbols. This is especially useful in so-called PCM modulation schemes that utilize the DTN, where knowledge of network and DAC distortion predicates the selection of available PCM codes used to represent data. This information is also useful when the data receiver, or PCM modem, makes determinations of which codes were actually sent.

    摘要翻译: 本发明提供一种生成可用于确定利用公共数字电话网(DTN)的通信信道的特征响应的信号的方法。 该信道包括可以具有网络数字衰减器(NDA)和/或Robbed位信令(RBS)以及数模转换器(DAC)(也称为编解码器)的DTN,以及模拟 本地环路的特性,通常是双绞铜线。 本发明提供一种确定接收数据流的最佳采样时刻的方法和装置。 本发明提供了一种非常适合用于确定信道对用作数据符号的已知PCM码的序列的响应的探测信号。 这在使用DTN的所谓PCM调制方案中特别有用,其中网络和DAC失真的知识预示着用于表示数据的可用PCM码的选择。 当数据接收器或PCM调制解调器确定实际发送哪些代码时,该信息也是有用的。

    Method and apparatus for regenerating symbol timing from a probing
signal in a system having non-linear network and codec distortion
    4.
    发明授权
    Method and apparatus for regenerating symbol timing from a probing signal in a system having non-linear network and codec distortion 失效
    用于在具有非线性网络和编解码器失真的系统中从探​​测信号再生符号定时的方法和装置

    公开(公告)号:US5991348A

    公开(公告)日:1999-11-23

    申请号:US909860

    申请日:1997-08-12

    摘要: The present invention provides a method of generating a signal that may be used to determine the characteristic response of a communication channel that utilizes the public Digital Telephone Network (DTN). The channel includes the DTN, which may have Network Digital Attenuators (NDA) and/or Robbed Bit Signalling (RBS), and a Digital-to-Analog Converter (DAC), (also known as a codec), as well as the analog characteristics of the local loop, typically a twisted pair of copper wires. The present invention provides a method and apparatus to determine the optimal sampling instant of the received data stream. The present invention provides a probing signal that is well-suited for use in determining the channel's response to a known sequence of PCM codes used as data symbols. This is especially useful in so-called PCM modulation schemes that utilize the DTN, where knowledge of network and DAC distortion predicates the selection of available PCM codes used to represent data. This information is also useful when the data receiver, or PCM modem, makes determinations of which codes were actually sent.

    摘要翻译: 本发明提供一种生成可用于确定利用公共数字电话网(DTN)的通信信道的特征响应的信号的方法。 该信道包括可以具有网络数字衰减器(NDA)和/或Robbed位信令(RBS)以及数模转换器(DAC)(也称为编解码器)的DTN,以及模拟 本地环路的特性,通常是双绞铜线。 本发明提供一种确定接收数据流的最佳采样时刻的方法和装置。 本发明提供了一种非常适合用于确定信道对用作数据符号的已知PCM码的序列的响应的探测信号。 这在使用DTN的所谓PCM调制方案中特别有用,其中网络和DAC失真的知识预示着用于表示数据的可用PCM码的选择。 当数据接收器或PCM调制解调器确定实际发送哪些代码时,该信息也是有用的。

    Method and apparatus for generating a probing signal for a system having
non-linear network and codec distortion
    5.
    发明授权
    Method and apparatus for generating a probing signal for a system having non-linear network and codec distortion 失效
    用于产生具有非线性网络和编解码器失真的系统的探测信号的方法和装置

    公开(公告)号:US5970089A

    公开(公告)日:1999-10-19

    申请号:US909997

    申请日:1997-08-12

    摘要: The present invention provides a method of generating a signal that may be used to determine the characteristic response of a communication channel that utilizes the public Digital Telephone Network (DTN). The channel includes the DTN, which may have Network Digital Attenuators (NDA) and/or Robbed Bit Signalling (RBS), and a Digital-to-Analog Converter (DAC), (also known as a codec), as well as the analog characteristics of the local loop, typically a twisted pair of copper wires. The present invention provides a method and apparatus to determine the optimal sampling instant of the received data stream. The present invention provides a probing signal that is well-suited for use in determining the channel's response to a known sequence of PCM codes used as data symbols. This is especially useful in so-called PCM modulation schemes that utilize the DTN, where knowledge of network and DAC distortion predicates the selection of available PCM codes used to represent data. This information is also useful when the data receiver, or PCM modem, makes determinations of which codes were actually sent.

    摘要翻译: 本发明提供一种生成可用于确定利用公共数字电话网(DTN)的通信信道的特征响应的信号的方法。 该信道包括可以具有网络数字衰减器(NDA)和/或Robbed位信令(RBS)以及数模转换器(DAC)(也称为编解码器)的DTN,以及模拟 本地环路的特性,通常是双绞铜线。 本发明提供一种确定接收数据流的最佳采样时刻的方法和装置。 本发明提供了一种非常适合用于确定信道对用作数据符号的已知PCM码的序列的响应的探测信号。 这在使用DTN的所谓PCM调制方案中特别有用,其中网络和DAC失真的知识预示着用于表示数据的可用PCM码的选择。 当数据接收器或PCM调制解调器确定实际发送哪些代码时,该信息也是有用的。

    In-Band signal and detector for PCM modem exception processing
    6.
    发明授权
    In-Band signal and detector for PCM modem exception processing 失效
    用于PCM调制解调器异常处理的带内信号和检测器

    公开(公告)号:US06373889B1

    公开(公告)日:2002-04-16

    申请号:US09085411

    申请日:1998-05-27

    IPC分类号: H03H2100

    CPC分类号: H04L5/1438

    摘要: A signal for exception processing is provided. The signal includes a first sequence of PCM codewords. Each PCM codeword in the sequence has a magnitude corresponding to a maximum point within an active constellation. The signal further includes a timing mark following the first sequence. In addition, a client device is provided. The client device includes a receiver and a detector coupled to the receiver. The receiver is coupled to an analog subscriber loop and has a decision feedback equalizer. The receiver provides a decision corresponding to data sent by a digital data source. The detector monitors the decision of the receiver to determine when an exception has been requested by the digital data source. Further, a method of requesting a change in a mode of operation of a client device when the client device is operating in a data mode is provided. The data mode includes receiving signal points selected from an active constellation and deciding which points have been received to thereby recover data. The method includes the step of transmitting, to the client device, a predetermined sequence of points from the active constellation. Each of the points in the predetermined sequence has the same index relative to a maximum point within the active constellation. The method further includes the steps of receiving the transmitted sequence, and detecting the predetermined sequence.

    摘要翻译: 提供异常处理信号。 信号包括PCM码字的第一序列。 序列中的每个PCM码字具有对应于活动星座内的最大点的幅度。 信号还包括第一序列之后的定时标记。 此外,还提供了客户端设备。 客户端设备包括接收器和耦合到接收器的检测器。 接收机耦合到模拟用户环路并具有判决反馈均衡器。 接收机提供与由数字数据源发送的数据相对应的决定。 检测器监视接收机的决定以确定数字数据源何时请求异常。 此外,提供了当客户端设备以数据模式操作时请求客户端设备的操作模式的改变的方法。 数据模式包括接收从活动星座中选出的信号点,并确定已经接收到哪些点,从而恢复数据。 该方法包括从客户端设备向活动星座发送预定的点序列的步骤。 预定序列中的每个点相对于活动星座图内的最大点具有相同的索引。 该方法还包括以下步骤:接收所发送的序列,并检测预定的序列。

    Timing Recovery using group delay compensation
    7.
    发明授权
    Timing Recovery using group delay compensation 失效
    使用组延迟补偿的定时恢复

    公开(公告)号:US5793821A

    公开(公告)日:1998-08-11

    申请号:US472918

    申请日:1995-06-07

    CPC分类号: H04L7/0029 H04L7/0278

    摘要: An electronic transmit/receive device employs an equalized envelope derived timing system to compensate for differential time delay occurring at upper and lower bandedges of the received signal. The received signal is split into a complex signal and the envelope derived timing system is utilized to perform amplitude and delay distortion compensation on the received signal. The amplitude and delay distortion compensation is performed by employing bandedge filters which preferably take the form of Finite Impulse Response (FIR) filters.

    摘要翻译: 电子发射/接收装置采用均衡的包络导出定时系统来补偿在接收信号的上限和下限带出现的差分时延。 接收到的信号被分割成复信号,并且使用包络导出定时系统对接收信号执行振幅和延迟失真补偿。 幅度和延迟失真补偿通过采用优选采用有限脉冲响应(FIR)滤波器形式的带状滤波器来执行。

    Communications methods and apparatus for using a single logical link with multiple physical layer connections
    10.
    发明授权
    Communications methods and apparatus for using a single logical link with multiple physical layer connections 有权
    用于使用具有多个物理层连接的单个逻辑链路的通信方法和装置

    公开(公告)号:US08995466B2

    公开(公告)日:2015-03-31

    申请号:US11316601

    申请日:2005-12-22

    CPC分类号: H04W88/08 H04L25/14 H04W88/10

    摘要: A base station uses a common link layer controller for multiple physical attachment points to facilitate concurrent wireless connections between different sector physical attachment points and a wireless terminal using the same link layer link. A wireless terminal maintains multiple simultaneous wireless connections for the same link layer link. A packet of user data is fragmented into a plurality of grouping of MAC frames, thus a packet portion can be communicated over a connection. A single packet is sometimes communicated with different portions conveyed over different wireless connections. Automatic repeat request, using the common link layer controller, allows for retransmission of a packet portion over a different connection than it was initially transmitted over. A wireless terminal sends connection request messages including lists of link layer identifiers associated with the wireless terminal. A base station responds with an indication of whether logical link state was already present.

    摘要翻译: 基站使用用于多个物理连接点的公共链路层控制器来促进不同扇区物理连接点之间的并发无线连接以及使用相同链路层链路的无线终端。 无线终端为相同的链路层链路维护多个同时的无线连接。 用户数据的分组被分段成多个MAC帧分组,因此可以通过连接来传送分组部分。 有时通过不同的部分在不同的无线连接上传送单个分组。 使用公共链路层控制器的自动重发请求允许通过不同于最初发送的连接重传分组部分。 无线终端发送包括与无线终端相关联的链路层标识符的连接请求消息。 基站响应是否存在逻辑链路状态的指示。