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    Transmission system for the transmission of data signals in a modulation band
    1.
    发明授权
    Transmission system for the transmission of data signals in a modulation band 失效
    用于在调制频带中传输数据信号的传输系统

    公开(公告)号：US4660216A

    公开(公告)日：1987-04-21

    申请号：US707701

    申请日：1985-03-04

    申请人： Theodoor A. C. M. Claasen ,  Gerardus F. M. Beenker ,  Petrus J. van Gerwen ,  Johannes M. Meijer ,  Martinus L. N. Didden

    发明人： Theodoor A. C. M. Claasen ,  Gerardus F. M. Beenker ,  Petrus J. van Gerwen ,  Johannes M. Meijer ,  Martinus L. N. Didden

    IPC分类号： H04L25/08 ,  H04B1/62 ,  H04L25/34

    CPC分类号： H04B1/62

    摘要： A transmission system for transmitting data signals in a modulation band comprising a transversal smearing filter at the transmitter end and a transversal desmearing filter at the receiver end. In order to obtain an optimum smearing efficiency, the sequence of real individual coefficients of the multiplying factors of the transversal desmearing filter satisfy the requirement that for a given upper limit for the intersymbol interference produced by the cascade arrangement formed by the smearing filter, and the desmearing filter a substantially maximum value is derived for a merit factor indicating by what factor the maximum value of a disturbance is decreased by including a smearing filter and a desmearing filter in the transmission system.

    摘要翻译： 一种传输系统，用于在包括发射机端的横向拖尾滤波器和接收机端的横向去噪滤波器的调制频带中传输数据信号。 为了获得最佳的拖尾效率，横向去除滤波器的乘法系数的实际个体系数的顺序满足对于由拖尾滤波器形成的级联布置产生的符号间干扰的给定上限的要求， 导出滤波器的基本上最大值，用于通过在传输系统中包括拖尾滤波器和去除滤波器来指示干扰的最大值由什么因素降低的优点因数。

    Conference system with automatic speaker detection and speaker unit
    2.
    发明授权
    Conference system with automatic speaker detection and speaker unit 失效
    具有自动扬声器检测和扬声器单元的会议系统

    公开(公告)号：US5404397A

    公开(公告)日：1995-04-04

    申请号：US41802

    申请日：1993-04-01

    申请人： Cornelis P. Janse ,  Johannes M. Meijer

    发明人： Cornelis P. Janse ,  Johannes M. Meijer

    IPC分类号： H04M3/56 ,  H04M9/08 ,  H04R3/02 ,  H04M1/20

    CPC分类号： H04R3/02 ,  H04M9/082

    摘要： A conference system comprises speaker units (12) coupled to a central unit (14). The speaker unit (12) comprises an echo canceller (20) with an adaptive filter (38) having an impulse response of comparatively short duration. In a speech pause of the user of the speaker unit (12) the common listening signal (LS) of the conference system is applied to the loudspeaker (18). Of the sounds then picked up by the microphone (16) only those sounds are compensated which are produced by the loudspeaker (18) and which reach the microphone (16) directly and which reach the microphone (16) indirectly via reflections from nearby objects. These sounds have a comparatively short impulse response time and enable a comparatively simple adaptive filter (38) to be used. The other sounds picked up by the microphone (16) reach the microphone (16) via reflections from the walls of the conference space (10) in which the conference system is situated. The other sounds have a comparatively long impulse response time. For the purpose of automatic speech detection these other sounds do not require echo cancellation because they are the same for all the speaker units. Automatic speech detection is now accomplished if the signal strength of the compensated microphone signal (MCCS) produced by the echo canceller (20) exceeds the average signal level of the speaker units.

    摘要翻译： 会议系统包括耦合到中央单元（14）的扬声器单元（12）。 扬声器单元（12）包括具有具有相对较短持续时间的脉冲响应的自适应滤波器（38）的回波消除器（20）。 在扬声器单元（12）的用户的语音暂停中，会议系统的公共收听信号（LS）被应用于扬声器（18）。 然后由麦克风拾取的声音（16）中，只有由扬声器（18）产生并直接到达麦克风（16）并通过来自附近物体的反射间接地到达麦克风（16）的那些声音被补偿。 这些声音具有相当短的脉冲响应时间，并且能够使用相对简单的自适应滤波器（38）。 由麦克风拾取的其他声音通过来自会议系统所在的会议空间（10）的墙壁的反射到达麦克风（16）。 其他声音具有比较长的脉冲响应时间。 为了自动语音检测，这些其他声音不需要回声消除，因为它们对于所有扬声器单元是相同的。 如果由回波消除器（20）产生的经补偿的麦克风信号（MCCS）的信号强度超过扬声器单元的平均信号电平，则现在完成自动语音检测。