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1. 发明授权

US6078645A Apparatus and method for monitoring full duplex data communications 失效
标题翻译：用于监控全双工数据通信的装置和方法
公开(公告)号：US6078645A
公开(公告)日：2000-06-20
申请号：US803475
申请日：1997-02-20
申请人： Lujing Cai , Herbert B. Cohen , Richard Rogoszewicz , Mingjie Wang
发明人： Lujing Cai , Herbert B. Cohen , Richard Rogoszewicz , Mingjie Wang
IPC分类号： H04M1/24 , H04M3/00
CPC分类号： H04B3/23
摘要： A modem monitor for monitoring full duplex communications comprises one receiver for each data stream and an echo canceler for canceling "far" echo. Prior to each receiver decoding the data stream it is designed to monitor, it replicates an echo expected to be found in its received data stream from a sample of each of the other predecoded data streams. The echo canceler then subtracts the expected echo from the received data stream to remove all far echoes caused by the other data streams. The echo canceled data stream is then decoded. The monitor can also include a data communications network interface and a sample rate converter operating with the PSTN for converting from the network transmission rate to the data transmission rate.
摘要翻译：用于监控全双工通信的调制解调器监视器包括用于每个数据流的一个接收器和用于消除“远”回波的回波消除器。在每个接收机解码数据流之前，它被设计为监视，它从其他预编码数据流中的每一个的样本复制期望在其接收的数据流中找到的回波。回波消除器然后从接收的数据流中减去预期的回波，以消除由其他数据流引起的所有远端回波。然后对回波抵消的数据流进行解码。监视器还可以包括数据通信网络接口和与PSTN一起工作的采样率转换器，用于从网络传输速率转换为数据传输速率。

2. 发明授权

US06331996B1 Channel synchronization and impulse sounding in the presence of frequency offset 失效
标题翻译：在频率偏移的情况下，通道同步和脉冲探测
公开(公告)号：US06331996B1
公开(公告)日：2001-12-18
申请号：US09086197
申请日：1998-05-28
申请人： Jenn-Shing Lin , Richard Rogoszewicz , Jin-Der Wang
发明人： Jenn-Shing Lin , Richard Rogoszewicz , Jin-Der Wang
IPC分类号： H04L2730
CPC分类号： H04L25/0226 , H04L2027/0065 , H04L2027/0095
摘要： A known training sequence of binary, pseudo random signals, PN, is received over the channel and correlated with a modified pseudo random sequence PN−1 in which the zeros of the known sequence PN have been mapped to −1. A transform of the correlator output will be observed to contain strong tones that indicate the degree of frequency offset. To facilitate synchronization in the presence of an unknown amount of frequency offset, the received signals may be rectified and the correlation step performed with the absolute value of the incoming signal to obtain new output samples. When the frequency offset is small its measurement is facilitated by modulating the incoming signals with a known, comparatively large frequency offset, before the correlation step to make sure that the overall frequency offset occurs around a frequency that is an integral multiple of the symbol rate divided by the number of symbols in the pseudo random sequence. After being compensated for the frequency offset, the received synchronization/sounding signal is used to sound the channel impulse response.
摘要翻译：通过信道接收二进制伪随机信号PN的已知训练序列，并将其与已知序列PN的零已映射到-1的经修改的伪随机序列PN-1相关联。将观察到相关器输出的变换，以包含指示频率偏移程度的强音调。为了在存在未知量的频率偏移的情况下促进同步，可以对接收的信号进行整流，并且用输入信号的绝对值执行相关步骤以获得新的输出采样。当频率偏移小时，通过在相关步骤之前用已知的相对较大的频率偏移调制输入信号来促进其测量，以确保总体频率偏移在分频符号速率的整数倍的频率周围出现通过伪随机序列中的符号数。在对频偏进行补偿之后，接收到的同步/探测信号用于发出信道脉冲响应。

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