Telecommunications transmission systems
    3.
    发明授权
    Telecommunications transmission systems 有权
    电信传输系统

    公开(公告)号:US07079610B1

    公开(公告)日:2006-07-18

    申请号:US09700617

    申请日:1999-05-11

    IPC分类号: H04B1/10

    摘要: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer from accepting time differences which should be corrected by operation of the sample clock controller.

    摘要翻译: 在采用OFDM的多载波系统中,例如DMT,通常使用自适应信道均衡器,在频域中工作。 控制采样时钟,以便有效地消除发射机和接收机之间的时间延迟。 如果从均衡数据流接收到用于控制采样时钟的信息,则会在通道均衡器的操作和用于控制采样时钟的机制之间引入歧义。 均衡器的操作可以掩盖采样时钟控制器应该跟踪的发射机和接收机之间的增加的时间差。 本发明通过防止均衡器接受应该通过采样时钟控制器的操作来校正的时间差来消除均衡器和采样时钟控制器的操作中的模糊性。

    In, or relating to, VDSL
    4.
    发明授权
    In, or relating to, VDSL 有权
    在或与VDSL有关

    公开(公告)号:US07113549B1

    公开(公告)日:2006-09-26

    申请号:US09622523

    申请日:1999-02-17

    IPC分类号: H04B15/00

    摘要: Zipper is the time-synchronized frequency-division duplex implementation of discrete multi-tome (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes injected into the received signal are orthogonal to the desired signal. The present invention provides a telecommunications transmission system using zipper and having at least two VDSL systems. Each VDSL system comprises a pair of zipper modems communicating over a cable transmission path. The telecommunications transmission system handles zipper transmission transmitted over the common cable; at least partly mitigates NEXT; and permits transmissions in a first VDSL system which are asynchronous with transmissions in a second VDSL system.

    摘要翻译: 拉链是离散多包(DMT)调制的时间同步分频双工实现。 两个通信的拉链调制解调器同时发送DMT符号与公共时钟。 当所有发射机都是时间同步时,注入接收信号的近端串扰(NEXT)和近端串扰回波正交于所需信号。 本发明提供一种使用拉链并具有至少两个VDSL系统的电信传输系统。 每个VDSL系统包括通过电缆传输路径通信的一对拉链调制解调器。 电信传输系统处理通过公共电缆传输的拉链传输; 至少部分减轻NEXT; 并允许与第二VDSL系统中的传输异步的第一VDSL系统中的传输。