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16 条记录 (耗时 0.048 秒)

    Selectable training signals based on stored previous connection information for DMT-based system
    4.
    发明申请
    Selectable training signals based on stored previous connection information for DMT-based system 有权

    公开(公告)号：US20050270987A1

    公开(公告)日：2005-12-08

    申请号：US11132147

    申请日：2005-05-18

    申请人： Yuanjie Chen

    发明人： Yuanjie Chen

    IPC分类号： H04L1/00 ,  H04L27/26 ,  H04J3/14 ,  G01R31/08 ,  G06F11/00 ,  G08C15/00 ,  H04B1/38 ,  H04J1/16 ,  H04L5/16 ,  H04L12/26

    CPC分类号： H04L27/261 ,  H04L1/0001 ,  H04L1/0006 ,  H04L27/2613

    摘要： Training signals can be chosen based on stored prior connection information to reduce the use of extra tones in transmitted training signals and thereby improve receiver performance. By choosing training signals based on the stored prior connection information, it is possible to make the training signals indirectly a function of the loop impairments. One advantage of this scheme is that we can choose to omit certain tones in the training signals, based on previous connection information, on a loop-by-loop basis. For example, in an ADSL Transceiver Unit-Central office end (ATU-C) device, per-local-loop prior connection information may be employed to select DMT tones to be included in downstream training signals. Similarly, in an ADSL Transceiver Unit-Remote terminal end (ATU-R) device, prior connection information may be employed to select DMT tones to be included in upstream training signals. In each case, local echoes are effectively reduced and local receiver training is improved without affecting eventual data transmission performance in the other direction. As a result, higher AGC gain and higher signal-to-quantization-noise ratios can be achieved, especially in the case of long loops. These benefits can allow (1) improvements in the loop performance in the receiving direction and/or (2) reductions in the requirements on the receiving ADC. In addition, crosstalks into the other wire pairs, especially those in the same bundle, are also reduced, improving the transmission environment on those pairs.

    Method and apparatus for implementing enhanced multiple modulus conversion techniques in a signal point mapping context
    6.
    发明授权
    Method and apparatus for implementing enhanced multiple modulus conversion techniques in a signal point mapping context 有权
    用于在信号点映射上下文中实现增强的多模转换技术的方法和装置

    公开(公告)号：US06438158B1

    公开(公告)日：2002-08-20

    申请号：US09476856

    申请日：2000-01-03

    申请人： Zhenyu Zhou ,  Xuming Zhang ,  Yuanjie Chen

    发明人： Zhenyu Zhou ,  Xuming Zhang ,  Yuanjie Chen

    IPC分类号： H04L516

    CPC分类号： H04L25/4927

    摘要： The present invention relates to multiple modulus conversion (MMC) techniques for mapping data in a pulse code modulation (PCM) modem system. In accordance with the present invention, signal point constellations are arranged to receive the output indices generated by the MMC procedure such that the probability of transmission of higher power codewords is relatively low compared to the probability of transmission of lower power codewords, while maintaining the same or larger minimum distance between signal points. In addition, the present invention provides techniques for obtaining the probability of occurrence for each constellation or signal point associated with a given data communication session and for determining the theoretical average transmit power associated with a given set of signal point constellations and MMC parameters. In addition, the present invention provides a method for estimating a reasonable upper bound for the average transmit power associated with a given set of signal point constellations and MMC parameters. The present invention is also capable of transmitting the codewords defined by an MMC procedure in a specific order that may be optimized in accordance with a particular cost function associated with the modem system.

    摘要翻译： 本发明涉及用于在脉码调制（PCM）调制解调器系统中映射数据的多模转换（MMC）技术。 根据本发明，信号点星座被布置为接收由MMC过程产生的输出索引，使得较低功率码字的传输概率相对较低的较高功率码字的发送概率相对较低，同时保持相同 或更大的信号点之间的最小距离。 此外，本发明提供了用于获得与给定数据通信会话相关联的每个星座或信号点的出现概率以及用于确定与给定的一组信号点星座和MMC参数相关联的理论平均发射功率的技术。 此外，本发明提供了一种用于估计与给定的信号点星座和MMC参数集合相关联的平均发射功率的合理上界的方法。 本发明还能够以可以根据与调制解调器系统相关联的特定成本函数进行优化的特定顺序来发送由MMC过程定义的码字。

    METHOD WITH IMPROVED PHASE ROBUSTNESS IN COHERENT DETECTED OPTICAL SYSTEM
    7.
    发明申请
    METHOD WITH IMPROVED PHASE ROBUSTNESS IN COHERENT DETECTED OPTICAL SYSTEM 有权
    在相干检测光学系统中改进相位稳定性的方法

    公开(公告)号：US20130315609A1

    公开(公告)日：2013-11-28

    申请号：US13480230

    申请日：2012-05-24

    申请人： Chuandong Li ,  Yuanjie Chen ,  Zhuhong Zhang ,  Yi Cai ,  Fei Zhu

    发明人： Chuandong Li ,  Yuanjie Chen ,  Zhuhong Zhang ,  Yi Cai ,  Fei Zhu

    IPC分类号： H04B10/06

    CPC分类号： H04B10/613 ,  H04B10/6164

    摘要： An optical signal receiver tracks local oscillator frequency offset (LOFO) and compensates for the phase distortion introduced in the received signals as a result of utilizing the local oscillator within a coherent detection scheme. This phase distortion is basically a constant phase rotation caused by the LOFO and implementation of the receiver using coherent detection and a digital interferometer instead of a conventional (yet complex) carrier phase estimation or recovery scheme. With an optical receiver implemented in this manner, the requirement of using a precise local oscillator laser with low frequency offset is less important.

    摘要翻译： 光信号接收器跟踪本地振荡器频率偏移（LOFO），并且通过在相干检测方案中利用本地振荡器来补偿在接收信号中引入的相位失真。 该相位失真基本上是由LOFO引起的恒定相位旋转和使用相干检测的接收机的实现以及数字干涉仪而不是常规（但复杂的）载波相位估计或恢复方案。 通过以这种方式实现的光接收机，使用具有低频偏移的精确本地振荡器激光器的要求不那么重要。

    Selectable training signals based on stored previous connection information for DMT-based system
    9.
    发明授权
    Selectable training signals based on stored previous connection information for DMT-based system 有权
    基于DMT系统存储的先前连接信息可选训练信号

    公开(公告)号：US07187696B2

    公开(公告)日：2007-03-06

    申请号：US11132147

    申请日：2005-05-18

    申请人： Yuanjie Chen

    发明人： Yuanjie Chen

    IPC分类号： H04J1/00

    CPC分类号： H04L27/261 ,  H04L1/0001 ,  H04L1/0006 ,  H04L27/2613

    摘要： Training signals can be chosen based on stored prior connection information to reduce the use of extra tones in transmitted training signals and thereby improve receiver performance. By choosing training signals based on the stored prior connection information, it is possible to make the training signals indirectly a function of the loop impairments. One advantage of this scheme is that we can choose to omit certain tones in the training signals, based on previous connection information, on a loop-by-loop basis. For example, in an ADSL Transceiver Unit-Central office end (ATU-C) device, per-local-loop prior connection information may be employed to select DMT tones to be included in downstream training signals. Similarly, in an ADSL Transceiver Unit-Remote terminal end (ATU-R) device, prior connection information may be employed to select DMT tones to be included in upstream training signals. In each case, local echoes are effectively reduced and local receiver training is improved without affecting eventual data transmission performance in the other direction. As a result, higher AGC gain and higher signal-to-quantization-noise ratios can be achieved, especially in the case of long loops. These benefits can allow (1) improvements in the loop performance in the receiving direction and/or (2) reductions in the requirements on the receiving ADC. In addition, crosstalks into the other wire pairs, especially those in the same bundle, are also reduced, improving the transmission environment on those pairs.

    摘要翻译： 可以基于存储的先前连接信息来选择训练信号，以减少所传送训练信号中额外音调的使用，从而提高接收机性能。 通过基于存储的先前连接信息选择训练信号，可以间接地使训练信号成为循环障碍的函数。 该方案的一个优点是，我们可以逐个循环地选择在训练信号中基于以前的连接信息省略某些音调。 例如，在ADSL收发单元 - 中心局端（ATU-C）设备中，可以采用每个本地环路以前的连接信息来选择要包括在下游训练信号中的DMT音调。 类似地，在ADSL收发器单元 - 远程终端（ATU-R）设备中，可以采用先前的连接信息来选择要包括在上行训练信号中的DMT音调。 在每种情况下，本地回波被有效地减少，并且本地接收机训练得到改善，而不影响另一方向的最终数据传输性能。 结果，可以实现更高的AGC增益和更高的信号与量化噪声比，特别是在长环路的情况下。 这些优点可以允许（1）改善接收方向的环路性能和/或（2）降低对接收ADC的要求。 此外，还减少了对另一个线对的串扰，特别是同一束中的串扰，从而改善了这些对上的传输环境。

    Method and apparatus for implementing enhanced multiple modulus conversion techniques in a signal point mapping context
    10.
    发明授权
    Method and apparatus for implementing enhanced multiple modulus conversion techniques in a signal point mapping context 失效

    公开(公告)号：US6034991A

    公开(公告)日：2000-03-07

    申请号：US13671

    申请日：1998-01-26

    申请人： Zhenyu Zhou ,  Xuming Zhang ,  Yuanjie Chen

    发明人： Zhenyu Zhou ,  Xuming Zhang ,  Yuanjie Chen

    IPC分类号： H04L25/49 ,  H04L5/16

    CPC分类号： H04L25/4927

    摘要： The present invention relates to multiple modulus conversion (MMC) techniques for mapping data in a pulse code modulation (PCM) modem system. In accordance with the present invention, signal point constellations are arranged to receive the output indices generated by the MMC procedure such that the probability of transmission of higher power codewords is relatively low compared to the probability of transmission of lower power codewords, while maintaining the same or larger minimum distance between signal points. In addition, the present invention provides techniques for obtaining the probability of occurrence for each constellation or signal point associated with a given data communication session and for determining the theoretical average transmit power associated with a given set of signal point constellations and MMC parameters. In addition, the present invention provides a method for estimating a reasonable upper bound for the average transmit power associated with a given set of signal point constellations and MMC parameters. The present invention is also capable of transmitting the codewords defined by an MMC procedure in a specific order that may be optimized in accordance with a particular cost function associated with the modem system.