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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。
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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。
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63.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
CPC分类号： H04L25/4927 , H04L1/242 , H04L5/1438 , H04L7/027 , H04L25/0226
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。
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64.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
CPC分类号： H04L7/027 , H04L7/0334 , H04L7/041
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。
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65.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
CPC分类号： H04L25/4927 , H04L1/242 , H04L25/0226 , H04L5/1438 , H04L7/027
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。
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