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公开(公告)号：US5444712A
公开(公告)日：1995-08-22
申请号：US113113
申请日：1993-08-30
申请人： William L. Betts , Eran Cohen , Joseph A. Crupi , Cletus L. Gardenhour , Andrew T. Weitzner , Jean-Jacques Werner
发明人： William L. Betts , Eran Cohen , Joseph A. Crupi , Cletus L. Gardenhour , Andrew T. Weitzner , Jean-Jacques Werner
CPC分类号： H04L27/34
摘要： A technique for use in communications systems utilizing busy and idle modes. In the busy mode, symbols representative of data are transmitted to system end users. In the idle mode, during which no data is communicated to end users, idle mode symbols are transmitted. Such idle mode symbols are not used to represent data and are only transmitted during the idle mode. Advantageously, such idle mode symbols maintain adaptive apparatus, such as AGC circuits, NEXT cancellers and equalizers, in their properly converged state. In the disclosed embodiment, the idle mode symbols are the innermost symbols in a signal constellation and transition from the idle to busy mode is represented by the transmission of a predetermined number of outermost symbols in the signal constellation. Use of such symbols for idle-to-busy mode transitions advantageously provides ready detection of such transitions. In addition, use of the innermost symbols for the idle mode reduces spectral emission and crosstalk.
摘要翻译： 一种在使用忙碌和空闲模式的通信系统中使用的技术。 在忙模式下，代表数据的符号被发送给系统终端用户。 在空闲模式中，在此期间没有数据传送给终端用户，发送空闲模式符号。 这种空闲模式符号不用于表示数据，并且仅在空闲模式期间传输。 有利的是，这种空闲模式符号在自适应收敛状态下保持自适应装置，例如AGC电路，NEXT消除器和均衡器。 在所公开的实施例中，空闲模式符号是信号星座中的最内符号，并且从空闲模式到忙模式的转换由信号星座图中预定数量的最外边符号的传输来表示。 使用这种符号进行空闲到忙模式转换有利地提供了对这种转换的即时检测。 此外，对于空闲模式使用最内部的符号减少了频谱发射和串扰。
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公开(公告)号：US5541964A
公开(公告)日：1996-07-30
申请号：US533143
申请日：1995-09-25
CPC分类号： H04L27/34 , H04L2007/045
摘要： Symbols which are representative of customer data are transmitted in bursts. In the idle mode, i.e., the time intervals between bursts, symbol sequences which are a priori known to the receiver are transmitted. Such idle mode symbols maintain adaptive apparatus, such as NEXT cancellers and equalizers, in their properly converged state. To reduce crosstalk and spectral emissions, the idle mode symbols are selected to be the innermost symbols in the signal constellation encompassing the ensemble of all symbols.
摘要翻译： 以突发方式传送代表客户数据的符号。 在空闲模式下，即突发之间的时间间隔，发送接收机已知的先验符号序列。 这种空闲模式符号在自适应收敛状态下保持自适应装置，例如NEXT消除器和均衡器。 为了减少串扰和频谱发射，空闲模式符号被选择为包含所有符号的集合的信号星座中的最内部符号。
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公开(公告)号：US6009083A
公开(公告)日：1999-12-28
申请号：US22708
申请日：1998-02-12
IPC分类号： H04B3/23
CPC分类号： H04B3/23
摘要： The problem of tracking rapid changes in the echo signals associated with modems is eliminated by using an echo canceler consisting of cascaded adaptive filters. Each filter in the structure contributes to the modeling of the overall echo path impulse response, with a longer filter providing the ability to model long echo path impulse responses and a shorter filter providing the ability to track changes in the echo path impulse response over time.
摘要翻译： 通过使用由级联自适应滤波器组成的回波消除器来消除跟踪与调制解调器相关联的回波信号的快速变化的问题。 该结构中的每个滤波器有助于对整个回波路径脉冲响应的建模，其中较长的滤波器提供对长回波路径脉冲响应建模的能力，以及较短的滤波器，提供跟踪随时间的回波路径脉冲响应变化的能力。
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公开(公告)号：US5805696A
公开(公告)日：1998-09-08
申请号：US762554
申请日：1996-12-09
CPC分类号： H04M9/082
摘要： A device for providing conferencing communications. The device comprises: a summing circuit for forming a signal sum equal to a sum of signals received from at least three information signal sources along with an echo compensation signal, the signal received from each information source including echoes and the signal sum including an aggregation of such echoes; an adaptive filter having an input and an output, the input being solely responsive to the signal sum and the output being only coupled to the summing circuit, the filter forming the echo compensation signal which is an estimate of the aggregation of echoes; and a low level training sequence generator having an amplitude less than a predetermined level. The adaptive filter has coefficients whose respective values are varied in response to a training sequence comprising a plurality of a priori known values supplied by the low level training sequence generator and the predetermined level is below that of the signal received from the each information source.
摘要翻译： 用于提供会议通信的设备。 该装置包括：求和电路，用于形成等于从至少三个信息信号源接收的信号之和以及回波补偿信号的信号总和，从包括回波的每个信息源接收的信号和包括聚合的信号和 这样的回声; 具有输入和输出的自适应滤波器，所述输入仅响应于所述信号和并且所述输出仅耦合到所述求和电路，所述滤波器形成作为所述回波的聚合的估计的所述回波补偿信号; 以及具有小于预定电平的振幅的低电平训练序列发生器。 自适应滤波器具有响应于包括由低电平训练序列发生器提供的多个先验已知值的训练序列而变化的系数，并且预定电平低于从每个信息源接收的信号的训练序列。
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公开(公告)号：US5524025A
公开(公告)日：1996-06-04
申请号：US976625
申请日：1992-11-16
IPC分类号： H03M13/00 , H04B14/04 , H04L27/34 , H04N5/44 , H04N7/08 , H04N7/26 , H04N7/30 , H04B7/00 , H04B15/00
CPC分类号： H04L27/3427 , H04L27/3488 , H04N5/4401 , H04N7/08
摘要： Digital signals, such as digitized television signals, are subjected to a source coding step followed by a channel mapping step. The source coding step causes the television signal to be represented by two or more data streams while, in the channel mapping step, the mapping is such that the data elements of the various data streams have differing probabilities of being erroneously detected at the receiver. In preferred embodiments, a first one of the aforementioned data streams carries components of the overall television signal which are regarded as the most important--for example the audio, the framing information, and the vital portions of the video information, such as motion compensation information--and that data stream is mapped such that its data elements have the lowest probability of error. A second one of the data streams carries components of the overall television signal which are regarded as less important than those of the first data stream and that data stream is mapped such that its data elements have a probability of error that is not as low as those of the first data stream. In general, it is possible to represent the overall television signal with any number of data streams, each carrying components of varying importance and each having a respective probability of error. This approach allows a graceful degradation in reception quality at, for example, the television set location because as the bit error rate at the receiver begins to increase with increasing distance from the broadcast transmitter, the bits that represent proportionately less of the video information will be the first to be affected.
摘要翻译： 诸如数字化电视信号的数字信号经受源编码步骤之后是频道映射步骤。 源编码步骤使得电视信号由两个或多个数据流表示，而在信道映射步骤中，映射使得各种数据流的数据元素具有在接收机处被错误检测的不同概率。 在优选实施例中，前述数据流中的第一数据流携带被认为是最重要的整个电视信号的组件，例如视频信息的音频，成帧信息和重要部分，诸如运动补偿信息 并且该数据流被映射，使得其数据元素具有最低的错误概率。 数据流中的第二个携带整个电视信号的组件，这些组件被认为不如第一数据流的那些重要，并且该数据流被映射，使得其数据元素的误差概率不如那些低 的第一个数据流。 通常，可以用任何数量的数据流表示整个电视信号，每个数据流携带不同重要性并且各自具有相应的误差概率的分量。 这种方法允许在例如电视机位置处的接收质量的平稳降级，因为随着距离广播发射机的距离的增加，接收机的比特错误率开始增加，所以代表比例较小的视频信息的比特将是 首先受到影响
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公开(公告)号：US5164963A
公开(公告)日：1992-11-17
申请号：US611225
申请日：1990-11-07
CPC分类号： H04L27/3427 , H04L27/3488 , H04N5/4401 , H04N7/08
摘要： Digital signals, such as digitized television signals, are subjected to a source coding step followed by a channel mapping step. The source coding step causes the television signal to be represented by two or more data streams while, in the channel mapping step, the mapping is such that the data elements of the various data streams have differing probabilities of being erroneously detected at the receiver. In preferred embodiments, a first one of the aforementioned data streams carries components of the overall television signal which are regarded as the most important--for example the audio, the framing information, and the vital portions of the video information, such as motion compensation information--and that data stream is mapped such that its data elements have the lowest probability of error. A second one of the data streams carries components of the overall television signal which are regarded as less important than those of the first data stream and that data stream is mapped such that its data elements have a probability of error that is not as low as those of the first data stream. In general, it is possible to represent the overall television signal with any number of data streams, each carrying components of varying importance and each having respective probability of error. This approach allows a graceful degradation in reception quality at, for example, the television set location because as the bit error rate at the receiver begins to increase with increasing distance from the broadcast transmitter, the bits that represent proportionately less of the video information will be the first to be affected.
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7.发明授权Frequency division duplexing system which accommodates symmetric and asymmetric channels 失效频分双工系统，适用于对称和不对称的通道公开(公告)号：US06333920B1
公开(公告)日：2001-12-25
申请号：US08926497
申请日：1997-09-08
IPC分类号： H04J100
CPC分类号： H04L5/143 , H04M11/062
摘要： A communications system employs frequency division duplexing to accommodate symmetric and asymmetric services, while substantially eliminating near-end cross talk. Upstream and downstream channels are separated by a guard band in order to insure that near-end cross talk is kept to a minimum. An asymmetric upstream channel is preferably located at a lower frequency range than that of the asymmetric downstream channel. The guard band between these asymmetric upstream and downstream channels shifts in frequency along with the shift in frequency of the respective upstream and downstream channels as a function of reach. This guard band shifting permits the communications systems to utilize a greater percentage of the frequencies available to it and to thereby substantially maximize the communications rate that it can support. Although the asymmetric guard band is allowed to shift in the manner described, it is not allowed to do so in a manner that would create a conflict with symmetric channels. Additionally, for symmetric services upstream channels are provided both above and below a downstream channel and are located so as not to interfere with asymmetric channels.
摘要翻译： 通信系统采用频分双工技术来适应对称和非对称业务，同时基本消除近端串扰。 上游和下游通道被保护带隔开，以确保将近端串扰保持在最低限度。 非对称上行信道优选位于比不对称下行信道的频率范围更低的频率范围。 这些不对称上行和下行信道之间的保护频带随着各个上行和下行信道的频率偏移而随着距离的变化而变化。 这种保护频带移位允许通信系统利用可用的更大百分比的频率，从而使其可以支持的通信速率基本上最大化。 虽然允许非对称保护频带以所描述的方式进行移位，但是不允许以与对称信道产生冲突的方式这样做。 另外，对于对称业务，在下游信道的上方和下方提供上行信道，并且被定位成不干扰非对称信道。
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公开(公告)号：US06252903B1
公开(公告)日：2001-06-26
申请号：US09109364
申请日：1998-07-02
申请人： Jean-Jacques Werner , Jian Yang
发明人： Jean-Jacques Werner , Jian Yang
IPC分类号： H04L2701
CPC分类号： H04L25/03044 , H04L25/0305 , H04L25/4921 , H04L27/38 , H04L2025/0342 , H04L2025/03509 , H04L2025/03617 , H04L2025/0363 , H04L2025/03732
摘要： A receiver has a dual mode of operation—a carrierless amplitude modulation/phase modulation (CAP) mode and a quadrature amplitude modulation (QAM) mode-yet only requires a single equalizer structure for both the CAP mode of operation and the QAM mode of operation during blind start-up. The receiver uses the same blind equalization updating algorithm independent of the type of received signal for converging the equalizer structure. The blind equalization updating algorithm incorporates a constant R, whose value is a function of the type of received signal, e.g., a QAM signal or a CAP signal. The type of received signal is determined as a function of the in-phase component of the mean-squared error, E[e2n.
摘要翻译： 接收机具有双重操作模式 - 无载波幅度调制/相位调制（CAP）模式和正交幅度调制（QAM）模式 - 但是仅需要CAP操作模式和QAM操作模式的单个均衡器结构 在盲人启动期间。 接收机使用与接收信号类型无关的盲均衡更新算法，用于收敛均衡器结构。 盲均衡更新算法包含常数R，其值是接收信号类型的函数，例如QAM信号或CAP信号。 接收信号的类型被确定为均方误差E [e2n]的同相分量的函数。
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公开(公告)号：US6075816A
公开(公告)日：2000-06-13
申请号：US757207
申请日：1996-11-27
申请人： Jean-Jacques Werner , Jian Yang
发明人： Jean-Jacques Werner , Jian Yang
IPC分类号： H03H15/00 , H03H17/00 , H03H21/00 , H04B3/06 , H04L25/03 , H04L25/49 , H04L27/01 , H04L27/38 , H03N7/30
CPC分类号： H04L25/0305 , H04L25/4921 , H04N5/211
摘要： A blind convergence technique is restricted to using a subset of equalizer output samples. Illustratively, a receiver implements a windowed MMA approach. In this windowed MMA approach, a sample window overlays the two-dimensional plane representing the set of equalizer output samples. Only those equalizer output samples appearing within the sample window are used during filter adaptation.
摘要翻译： 盲收敛技术被限制为使用均衡器输出样本的子集。 说明性地，接收机实现窗口化的MMA方法。 在这种窗口化的MMA方法中，样本窗口覆盖表示均衡器输出样本集的二维平面。 滤波器适配期间仅使用出现在样本窗口内的均衡器输出样本。
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公开(公告)号：US5815496A
公开(公告)日：1998-09-29
申请号：US536905
申请日：1995-09-29
IPC分类号： H04B3/23
CPC分类号： H04B3/23
摘要： The problem of tracking rapid changes in the echo signals associated with modems is eliminated by using an echo canceler consisting of cascaded adaptive filters. Each filter in the structure contributes to the modeling of the overall echo path impulse response, with a longer filter providing the ability to model long echo path impulse responses and a shorter filter providing the ability to track changes in the echo path impulse response over time.
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