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公开(公告)号：US5278900A
公开(公告)日：1994-01-11
申请号：US680485
申请日：1991-04-04
CPC分类号： H04B3/234
摘要： A digital echo canceller has a receive path (2) and a send path (3) and comprises combining apparatus (10) for forming a send output signal [r(k)] as the difference between the signal [z(k)] applied to the send input (SI) and a replica signal [e(t)] used for cancelling an additive echo signal [e(k)] at the send input (SI) that has developed in response to a receive input signal [x(k)] applied to the receive input (RI), which echo canceller at least includes transforming apparatus (13, 15) for transforming the receive input signal [x(k)] and the send output signal [r(k)]; transforming apparatus (14) for transforming the replica signal [e(k)]; a digital adaptive filter (9) which has a number of filter coefficients for generating the replica signal [e(t)] in response to the receive input signal [x(k)] and the send output signal [r(k)], adaptation apparatus (12) for determining for each block m, adaptation components [A(p;m)] for each of the filter coefficients [W(p;m)] in response to the receive input signal [x(k)] and the send output signal [r(k)]; controllable gate means (17) for selectively passing the adaptation components [A(p;m)] to the adaptive digital filter (9); control apparatus (25-28, 21-24, 16) for determining respective levels of the send output signal [r(k)] and the receive input signal [x(k)] and for generating a control signal for the gate apparatus (17) in response to the levels thus determined, which control signals depend in a predetermined manner on the difference between the levels concerned.
摘要翻译： 数字回声消除器具有接收路径（2）和发送路径（3），并且包括用于形成发送输出信号（r（k））的组合装置（10）作为施加的信号（z（k））之间的差 用于响应于接收输入信号而产生的发送输入（SI），用于消除加性回波信号（e（k））的发送输入（SI）和复制信号（e（t））（x（ k）），该回波消除器至少包括用于变换接收输入信号（x（k））和发送输出信号（r（k））的变换装置（13,15）; 变换装置（14），用于变换复制信号（e（k））; 响应于接收输入信号（x（k））和发送输出信号（r（k）），具有用于产生复制信号（e（t））的滤波器系数的数字自适应滤波器（9） 适应装置（12），用于响应于接收输入信号（x（k））为每个块m确定每个滤波器系数（W（p; m））的适应分量（A（p; m）），以及 发送输出信号（r（k））; 用于选择性地将自适应分量（A（p; m））传递到自适应数字滤波器（9）的可控门装置（17）; 控制装置（25-28,21-24,16），用于确定发送输出信号（r（k））和接收输入信号（x（k））的各个电平，并用于产生门装置的控制信号 17）响应于如此确定的电平，哪个控制信号以预定的方式取决于所涉及的电平之间的差异。
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2.发明授权Arrangement for correcting pulse distortion in homochronous data transmission 失效用于校正同步数据传输中的脉冲失真的布置
公开(公告)号：US4464746A
公开(公告)日：1984-08-07
申请号：US342984
申请日：1982-01-26
CPC分类号： H04L25/03038 , H04B3/231 , H04L25/03057
摘要： In the duplex transmission of data signals over two-wire transmission paths the phenomenon of echo-signals is encountered, while simultaneously intersymbol interference occurs between the data symbols themselves. In order to reduce the influence of both the echo signals, and the intersymbol interference, the arrangement comprises a random access memory (16) which produces a correction value (c(i)) at each sampling instant to correct the received data signal. The memory is addressed from registers (13, 14) and a counter (15), the contents of the registers being determined by the data ssymbols transmitted last and the data symbols received last, respectively. A D-A converter (19) converts the correction value into a correction signal (c(t)), which in a difference producer (20) is subtracted from the received data signal. A sampling arrangement (21) samples the corrected received data signal. After D-A conversion (22) and multiplication (17) by a predetermined factor .alpha. each sample furnishes a number by which the correction value is changed to match it to the value of the pulse distortion at the sampling instant.
摘要翻译： 在通过双线传输路径的数据信号的双工传输中，遇到回波信号的现象，同时在数据符号本身之间同时发生符号间干扰。 为了减少回波信号和符号间干扰的影响，该装置包括在每个采样时刻产生校正值（c（i））的随机存取存储器，以校正接收到的数据信号。 存储器从寄存器（13,14）和计数器（15）寻址，寄存器的内容分别由最后发送的数据符号和最后接收的数据符号确定。 D-A转换器（19）将校正值转换成从接收到的数据信号中减去差分产生器（20）的校正信号（c（t））。 采样装置（21）对经校正的接收数据信号进行采样。 在D-A转换（22）和乘法（17）乘以预定因子α之后，每个样本提供校正值改变的数量，使其与采样时刻的脉冲失真值相匹配。
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公开(公告)号：US4349889A
公开(公告)日：1982-09-14
申请号：US168211
申请日：1980-07-10
申请人： Hendricus C. van den Elzen , Petrus J. Van Gerwen , Wilfred A. M. Snijders , Nicolaas A. M. Verhoeckx
发明人： Hendricus C. van den Elzen , Petrus J. Van Gerwen , Wilfred A. M. Snijders , Nicolaas A. M. Verhoeckx
CPC分类号： H04L25/03038
摘要： Arrangement having a non-recursive filter and means for weighting a sequence of delayed versions of the input signal in accordance with a sequence of coefficients which are each adjusted iteratively by positive and negative correction steps, respectively, with variable step-sizes, the step-size parameter being selected for each iteration and for each coefficient by means of a run-length detector to which the sign of each correction step is applied and which selects a larger or a smaller step-size parameter depending on the number of correction steps having the same sign and preceding the relevant iteration.Use: echo canceller, equalizer.
摘要翻译： 具有非递归滤波器的装置和用于根据系数序列对输入信号的延迟版本序列进行加权的装置，该系列序列分别通过具有可变步长的正和负校正步骤反复地进行调整， 通过使用每个校正步骤的符号的游程长度检测器对每个迭代选择每个系数的大小参数，并且根据具有该校正步骤的校正步骤的数量来选择更大或更小的步长参数 相同的符号，并在相关迭代之前。 使用：回波消除器，均衡器。
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公开(公告)号：US4317212A
公开(公告)日：1982-02-23
申请号：US134035
申请日：1980-03-26
CPC分类号： H04L7/027
摘要： Arrangement for checking the synchronization of a data signal receiver. When frequency division is used as part of the clock signal regeneration process, a phase ambiguity may occur. To eliminate this ambiguity use is made of a monitoring device. In the present monitoring circuit the data signal is sampled twice in each symbol interval and a reliable criterion is obtained by integration of the amplitude differences of the samples.
摘要翻译： 用于检查数据信号接收器的同步的装置。 当使用分频作为时钟信号再生处理的一部分时，可能会发生相位模糊。 为了消除这种模糊性，使用监控设备。 在本监视电路中，数据信号在每个符号间隔中被采样两次，并且通过积分样本的振幅差来获得可靠的标准。
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公开(公告)号：US4313088A
公开(公告)日：1982-01-26
申请号：US137866
申请日：1980-04-07
CPC分类号： H04L7/027
摘要： Arrangement for clock signal generation from a received data signal located in baseband, for use in baseband modems. In addition to signal transitions which provide clock information in a reliable manner, several types of data signals contain disturbing signal transitions. These disturbing transitions are eliminated by converting the spectrum of the received data signal into the spectrum of a bi-phase modulated signal. It is possible to obtain a reliable clock signal from the signal transitions of the converted signal with small acquisition times.
摘要翻译： 从位于基带的接收数据信号产生时钟信号的布置，用于基带调制解调器。 除了以可靠的方式提供时钟信息的信号转换之外，几种类型的数据信号包含干扰信号转换。 通过将接收的数据信号的频谱转换成双相调制信号的频谱来消除这些干扰转换。 可以从小的采集时间的转换信号的信号转换中获得可靠的时钟信号。
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公开(公告)号：US4125866A
公开(公告)日：1978-11-14
申请号：US807168
申请日：1977-06-16
CPC分类号： H03H17/06
摘要： A non-recursive discrete filter for simultaneously realizing for example two band-pass filter characteristics starting from a given lowpass transfer characteristic, wherein one bandpass filter has an in-phase transfer characteristic and the other filter the quadrature transfer characteristic of this in-phase filter. The central frequency of these filters is f.sub.o and the output sampling frequency is f.sub.s = 8f.sub.o. This discrete filter comprises multiplying means in which input signal samples x(n) are modified by an associated filter coefficient a(i) for generating modified input signal samples z(n,i) = a(i)x(n-i). The coefficients a(i) are the same for both transfer characteristics and are given by: ##EQU1## WHEREIN H.sub.1 (I) REPRESENTS THE DISCRETE IMPULSE RESPONSE OF THE LOWPASS FILTER.To realize the in-phase transfer characteristic the samples z(n,i) are thereafter multiplied by a factor sgn[cos (.pi.i/4)] and the products thus obtained are accumulated.This results in the output signal sample ##EQU2## To realize the quadrature transfer characteristic the samples z(n,i) are thereafter multiplied by a factor sgn[sin(.pi.i/4)] and the products thus obtained are accumulated. This results in the output signal sample ##EQU3##
摘要翻译： 一种非递归离散滤波器，用于从给定的低通传输特性开始同时实现两个带通滤波器特性，其中一个带通滤波器具有同相传输特性，另一个滤波器具有该同相滤波器的正交传输特性 。 这些滤波器的中心频率为fo，输出采样频率为fs = 8fo。 该离散滤波器包括乘法装置，其中输入信号采样x（n）由用于产生经修改的输入信号样本z（n，i）= a（i）x（n-1））的相关联的滤波器系数a（i）修改。 对于两个传送特性，系数a（i）相同，并由下式给出：对于cos（pi i / 4），a（i）= h 1（i）| cos（pi i / 4） = 1（i）| sin（pi i / 4）|对于cos（pi i / 4）= 0 WHEREIN H1（I）表示低通滤波器的离散冲击响应。
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公开(公告)号：US4835765A
公开(公告)日：1989-05-30
申请号：US002080
申请日：1987-01-12
CPC分类号： H04L5/1423 , H04B3/23
摘要： An arrangement for full-duplex data transmission over a two-wire circuit (1) comprises a transmit channel (2) connected to a baseband data transmitter (6) and including a smearing filter (18), a receive channel (3) connected to a baseband data receiver (9) and including a complementary smearing filter (19), a hybrid junction (4), an echo canceller (14) with an adaptive filter (15) and an adjusting circuit (16), and a combining circuit (17) inserted in the receive channel (3). Despite the application of the smearing filters (18, 19) the complexity of the echo canceller (14) is not increased as the arrangement comprises first and second delay means (20, 21) with a delay (D) corresponding to the signal delay of the cascade connection of the smearing filters (18, 19), the first delay means (20) having been inserted in a first signal path from the output of data transmitter (6) to the adjusting circuit (16) and the second delay means (21) having been inserted in a second signal path from the output of data transmitter (6) via the adaptive filter (15) and the combining circuit (17) to a point (P) in the receive channel (3) where the residual signal to be applied to the adjusting circuit (16) is tapped, and the complementary smearing filter (19) in the receive channel (3) has been inserted between the hybrid junction (4) and the tapping point (P) for the residual signal.
摘要翻译： 一种用于通过双线电路（1）进行全双工数据传输的装置包括连接到基带数据发射机（6）并包括拖尾滤波器（18）的发射信道（2），连接到 基带数据接收器（9），包括互补滤波器（19），混合结（4），具有自适应滤波器（15）和调整电路（16）的回波消除器（14）和组合电路 17）插入到接收通道（3）中。 尽管涂抹过滤器（18,19）的应用是回波消除器（14）的复杂度不增加，因为该装置包括第一和第二延迟装置（20,21），延迟装置（D）对应于信号延迟 拖尾滤波器（18,19）的级联连接，第一延迟装置（20）已被插入到从数据发射器（6）的输出到调节电路（16）的第一信号路径和第二延迟装置 21）从数据发送器（6）的输出经由自适应滤波器（15）和组合电路（17）插入到第二信号路径中，到达接收信道（3）中的点（P），其中剩余信号 被施加到调节电路（16）上，并且接收通道（3）中的互补拖尾滤波器（19）已经插入在混合结（4）和漏电点（P）之间用于残留信号。
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公开(公告)号：US4807173A
公开(公告)日：1989-02-21
申请号：US57561
申请日：1987-06-03
CPC分类号： H03H21/00 , H03H21/0027
摘要： A frequency-domain block-adaptive digital filter (FDAF) having a finite impulse response of length N for filtering a time-domain input signal in accordance with the overlap-save method includes window means (11) for obtaining modifications (B(p;m)) of the 2N frequency-domain weighting factors (W(p;m)) from correlation products (A(p;m)). A known FDAF of this type contains five 2N-point FFT's, two of which are used in the window means (11). By utilizing a special time-domain window function which can be implemented very efficiently in the window means (11) with the aid of a frequency-domain convolution, a FDAF of this type containing only three 2N-point FFT's is obtained whose convergence properties are comparable to those of the known FDAF containing five 2N-point FFT's.
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9.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
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。
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公开(公告)号：US4362909A
公开(公告)日：1982-12-07
申请号：US142304
申请日：1980-04-21
CPC分类号： H04L5/1423 , H04B3/23
摘要： Echo canceler for use in a data transmission system, comprising two and four-wire connections and arranged to suppress echo signals occurring in the four-wire connection. This echo canceler is provided with an adjustable signal processing device to which the data signal to be transmitted is applied and which produces a synthetic echo signal. A signal formed by a received data signal and an echo signal is present in the receive path of the four-wire connection. From the signals in the receive path there is now subtracted the synthetic echo signal, in order to generate a residual signal.To adjust the signal processing device an adjusting device is connected thereto to which a digital control signal is applied, which is constituted by a digital version of the residual signal.In order to improve the quality of the residual signal which is obtained when the data signal to be transmitted comprises long trains of data symbols of the same type the residual signal is subjected to a high-pass filter operation and the digital version of the residual signal filtered thus is applied to the adjusting device as the control signal.
摘要翻译： 回波消除器用于数据传输系统，包括两线和四线连接，并被布置成抑制在四线连接中发生的回波信号。 这个回波消除器设有一个可调信号处理装置，要发射的数据信号被应用到该可调信号处理装置，并产生合成的回波信号。 由接收的数据信号和回波信号形成的信号存在于四线连接的接收路径中。 从接收路径中的信号中，现在减去合成回波信号，以产生残余信号。 为了调整信号处理装置，连接有调制装置的数字控制信号被应用到数字控制信号，该数字控制信号由残留信号的数字版本构成。 为了提高要发送的数据信号包含相同类型的数据符号的长串获得的残留信号的质量，残差信号经受高通滤波操作，并且剩余信号的数字版本 滤波后作为控制信号施加于调整装置。
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