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公开(公告)号：US5363441A
公开(公告)日：1994-11-08
申请号：US195595
申请日：1994-02-14
摘要： Distortion and instability due to echoes in conference communications is reduced through the use of an echo estimating filter disposed in a conference bridging circuit. This circuit includes a signal combiner which receives information signals from each of the parties in the conference communications and provides an output signal which is a combination of the received information signals and an echo compensation signal. The echo estimating filter provides this echo compensation signal in response to the combiner output signal. Advantageously, the echo estimating filter can be fixed or adaptive. In the latter case, the adaptation can be in response to the received information signals or to training sequences.
摘要翻译： 通过使用布置在会议桥接电路中的回波估计滤波器，减少会议通信中回波引起的失真和不稳定性。 该电路包括在会议通信中从各方接收信息信号的信号组合器，并提供作为接收到的信息信号和回波补偿信号的组合的输出信号。 回波估计滤波器响应于组合器输出信号提供该回波补偿信号。 有利地，回波估计滤波器可以是固定的或适应的。 在后一种情况下，适应可以响应于所接收的信息信号或训练序列。
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公开(公告)号：US5331670A
公开(公告)日：1994-07-19
申请号：US830036
申请日：1992-01-31
CPC分类号： H04L27/3477 , H04J3/07
摘要： A synchronization scheme for a digital communications system wherein customer data is connected to a synchronous communications network utilizes auxiliary symbols to provide frame synchronization. Each such auxiliary symbol lies outside of a conventional symbol constellation and is only used to represent framing information. Variations of the customer data rate relative to an expected rate are compensated for by the use of stuff and delete bits in each frame. These bits can be either customer data bits or ancillary bits depending on the direction of this variation. Advantageously, the auxiliary symbols also provide a determination of whether the stuff and delete bits in any frame are customer data or ancillary bits.
摘要翻译： 其中客户数据连接到同步通信网络的数字通信系统的同步方案利用辅助符号来提供帧同步。 每个这样的辅助符号位于常规符号星座之外，并且仅用于表示成帧信息。 通过使用每个帧中的填充和删除位来补偿客户数据速率相对于期望速率的变化。 根据该变化的方向，这些位可以是客户数据位或辅助位。 有利地，辅助符号还提供确定任何帧中的填充和删除位是客户数据还是辅助位。
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公开(公告)号：US4943973A
公开(公告)日：1990-07-24
申请号：US331933
申请日：1989-03-31
申请人： Jean-Jacques Werner
发明人： Jean-Jacques Werner
IPC分类号： H04B1/707
CPC分类号： H04B1/707
摘要： A spread-spectrum signal which conveys identifying information for an associated information signal is superimposed on the associated signal and transmitted therewith. Such identifying information distinguishes between voice and data information signals and between different types of data information signals. Such identification can be used for a variety of purposes within a communications network, such as facility and equipment selection, equipment disablement and bypass, setting communications parameters, e.g., speed, and inhibiting communications upon fault detection.
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公开(公告)号：US4644537A
公开(公告)日：1987-02-17
申请号：US685445
申请日：1984-12-24
CPC分类号： H04L27/3472
摘要： In a system for communicating primary and secondary data from a transmitter to a receiver, each of a first plurality of primary data word values is communicated by transmitting an individual channel symbol associated with that value, while at least one other primary data word value is communicated by transmitting a selected one of at least two other channel symbols associated with that one other value. The selected symbol is a function of the value of an individual secondary data word. In the receiver, both the primary and secondary data word values are recovered from the channel symbols thus transmitted.
摘要翻译： 在用于将主数据和次要数据从发送器传送到接收器的系统中，通过发送与该值相关联的单独信道符号来传送第一多个主数据字值中的每一个，同时传达至少一个其它主数据字值 通过发送与该另一个值相关联的至少两个其他信道符号中的所选择的一个。 所选择的符号是单个辅助数据字的值的函数。 在接收机中，主数据字和辅助数据字值都从这样发送的信道符号恢复。
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公开(公告)号：US3991377A
公开(公告)日：1976-11-09
申请号：US637074
申请日：1975-12-02
IPC分类号： H04L27/233 , H03K9/04
CPC分类号： H04L27/2338
摘要： Disclosed is a Differential Phase Shift Keying demodulator employing a Hjlbert filter. Filtered and unfiltered signals are sampled at the symbol rate of an incoming signal, and the sampled signals are each applied to a delay element having a one-symbol period delay. The delayed and the undelayed replicas of the two sampled signals are linearly combined to form the demodulator's output signals.
摘要翻译： 公开了采用Hjlbert滤波器的差分相移键控解调器。 滤波和未滤波的信号以输入信号的符号速率被采样，并且采样信号各自被施加到具有一符号周期延迟的延迟元件。 两个采样信号的延迟和未延迟的副本被线性组合以形成解调器的输出信号。
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