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公开(公告)号：US4308505A
公开(公告)日：1981-12-29
申请号：US48027
申请日：1979-06-13
CPC分类号： H04L27/3818 , H04L7/033
摘要： A frequency detector and method for use in timing and carrier recovery applications. In a timing recovery application, the circuit includes means for generating a variable frequency periodic clock signal corresponding to an input data signal, means for determining whether successive data transitions of the data signal occur during first and second predetermined portions of successive cycles of the clock signal and means for changing the frequency of the clock signal when successive data transitions occur during different ones of the predetermined portions. For carrier recovery applications, the circuit includes means responsive to an input signal for generating a timing recovery signal, means for generating a local carrier signal having in-phase and quadrature axis components, means responsive to the local carrier signal and to the input signal for forming a baseband signal having in-phase and quadrature axis components, means responsive to the timing recovery signal for sampling the baseband signal at timing intervals corresponding to the timing recovery signal thereby forming a sample baseband signal, means for determining when the sample baseband signal occurs within a predetermined region of the in-phase axis or quadrature axis and means for changing the frequency of the carrier signal if successive samples are on opposite sides of the in-phase axis or quadrature axis.
摘要翻译： 用于定时和载波恢复应用的频率检测器和方法。 在定时恢复应用中，电路包括用于产生对应于输入数据信号的可变频率周期时钟信号的装置，用于确定数据信号的连续数据转换是否在时钟信号的连续周期的第一和第二预定部分期间发生的装置 以及用于当在不同的预定部分期间发生连续数据转换时改变时钟信号的频率的装置。 对于载波恢复应用，电路包括响应于输入信号以产生定时恢复信号的装置，用于产生具有同相和正交轴分量的本地载波信号的装置，响应于本地载波信号和输入信号的装置 形成具有同相和正交轴分量的基带信号，响应于定时恢复信号的装置，用于以对应于定时恢复信号的定时间隔采样基带信号，从而形成采样基带信号，用于确定采样基带信号何时发生的装置 在同相轴或正交轴的预定区域内，以及用于如果连续样本位于同相轴或正交轴的相对侧上则改变载波信号的频率的装置。
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2.发明授权Method and an apparatus for establishing the functional capabilities for wireless communications between a base unit and a remote unit 失效用于建立基本单元和远程单元之间的无线通信的功能能力的方法和装置
公开(公告)号：US5267244A
公开(公告)日：1993-11-30
申请号：US789348
申请日：1991-11-08
CPC分类号： H04M1/72502 , H03M13/31 , H03M5/145 , H04L25/4908
摘要： In a wireless communication system between a base unit and a remote unit, the base unit transmits periodically a sync signal in a first selected time period in a selected frequency channel. The remote unit scans the frequency channels to detect the sync signal. The remote unit transmits a response signal in the selected frequency channel. The response signal is transmitted in a second selected time period different from the first selected time period. In addition, the remote unit transmits a first control signal encoded by a first code in the selected frequency channel in a third selected time period, different from the first and second selected time periods, containing a set of functional capabilities of the remote unit. The base unit receives and decodes the first control signal to derive the set of functional capabilities of the remote unit and compares it to its own set of functional capabilities to determine a common set of functional capabilities. The base unit transmits a second control signal encoded by the first code in the same selected frequency channel in a fourth selected time period containing the common set of functional capabilities. Thereafter, communication between the base unit and the remote unit is based upon a functional capability selected from the common set.
摘要翻译： 在基本单元和远程单元之间的无线通信系统中，基站单元在所选择的频率信道中的第一选定时间周期内周期性地发送同步信号。 远程单元扫描频道以检测同步信号。 远程单元在所选择的频道中发送响应信号。 响应信号在与第一选择的时间段不同的第二选定时间段内发送。 此外，远程单元在与包含远程单元的一组功能能力的第一和第二选定时间段不同的第三选定时间段内发送由所选频道中的第一代码编码的第一控制信号。 基本单元接收并解码第一控制信号以导出远程单元的一组功能能力，并将其与其自己的一组功能能力进行比较，以确定一组共同的功能能力。 基站单元在包含公共功能能力集合的第四选定时间段内发送由相同选定频道中的第一代码编码的第二控制信号。 此后，基本单元和远程单元之间的通信基于从公共集合中选择的功能能力。
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公开(公告)号：US5258995A
公开(公告)日：1993-11-02
申请号：US789292
申请日：1991-11-08
申请人： Chun-Meng Su , Saman Behtash , Keith Jarett , Huihung Lu , Christopher Flores , David G. Messerschmitt
发明人： Chun-Meng Su , Saman Behtash , Keith Jarett , Huihung Lu , Christopher Flores , David G. Messerschmitt
CPC分类号： H04J1/12 , H03M13/31 , H03M5/145 , H04J3/0605 , H04L25/4908 , H04M1/72502 , H04J13/16
摘要： In the present invention a wireless communication system is disclosed. A base unit communicates with a remote unit. The system comprises means for transmitting, using CDMA, between the base unit and the remote unit, in one of a plurality of frequencies channels selected. In one period of time, the base unit transmits and in another period of time, different from the one period, the remote unit transmits. Further, the system comprises means for changing the one frequency channel selected to another frequency channel, different from the one frequency channel, in response to interference in the one frequency channel. Thus, communication between the base unit and the remote unit is then affected over the another frequency channel.
摘要翻译： 在本发明中，公开了一种无线通信系统。 基本单元与远程单元通信。 该系统包括用于在所选择的多个频率信道之一中使用CDMA在基本单元和远程单元之间进行发送的装置。 在一个时间段内，基站单元在远程单元发送的另一个时间段内发送不同于一个周期的时间段。 此外，该系统包括用于响应于一个频率信道中的干扰而将选择的一个频率信道改变为与一个频率信道不同的另一频率信道的装置。 因此，基本单元和远程单元之间的通信然后在另一频率信道上受到影响。
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公开(公告)号：US5398258A
公开(公告)日：1995-03-14
申请号：US143170
申请日：1993-10-26
申请人： Chun-Meng Su , Saman Behtash , Keith Jarett , Huihung Lu , Christopher Flores , David G. Messerschmitt , Edward Chien
发明人： Chun-Meng Su , Saman Behtash , Keith Jarett , Huihung Lu , Christopher Flores , David G. Messerschmitt , Edward Chien
CPC分类号： H04J1/12 , H03M13/31 , H03M5/145 , H04J3/0605 , H04L25/4908 , H04M1/72502 , H04J13/16
摘要： In the present invention a wireless communication system is disclosed. A base unit communicates with a remote unit. The system comprises means for transmitting, using CDMA, between the base unit and the remote unit, in one of a plurality of frequencies channels selected. In one period of time, the base unit transmits and in another period of time, different from the one period, the remote unit transmits. Further, the system comprises means for changing the one frequency channel selected to another frequency channel, different from the one frequency channel, in response to interference in the one frequency channel. Thus, communication between the base unit and the remote unit is then affected over the another frequency channel.
摘要翻译： 在本发明中，公开了一种无线通信系统。 基本单元与远程单元通信。 该系统包括用于在所选择的多个频率信道之一中使用CDMA在基本单元和远程单元之间进行发送的装置。 在一个时间段内，基站单元在远程单元发送的另一个时间段内发送不同于一个周期的时间段。 此外，该系统包括用于响应于一个频率信道中的干扰而将选择的一个频率信道改变为与一个频率信道不同的另一频率信道的装置。 因此，基本单元和远程单元之间的通信然后在另一频率信道上受到影响。
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公开(公告)号：US4145667A
公开(公告)日：1979-03-20
申请号：US832831
申请日：1977-09-13
CPC分类号： H03L7/1806
摘要： A reference source of digital pulses of a first frequency f.sub.1 is coupled to the input of a frequency synthesizer which is capable of providing a second frequency f.sub.2 output signal. The second frequency is related to the first frequency by a predetermined, rational fraction (e.g., as f.sub.2 = (M/N)f.sub.1). The synthesizer includes a phase control unit comprising an adder by way of which a first number N is added each sample period to a remainder, the sum output of the adder being operated upon modulo a second number M, e.g., by dividing by M and discarding a resultant quotient to obtain a remainder. The remainder, having a value between zero and M-1, is compared to a prefixed signal, illustratively the largest integer in M/2. If the remainder is less than the prefixed signal, a first logic state control signal is provided to a control system; else a second logic state signal is so provided. The alternation between the first and second logic states is such that M pulses of the second frequency occur for every N pulses of the first frequency. Thereby, the second frequency is synthesized responsive to the first.
摘要翻译： 第一频率f1的数字脉冲的参考源耦合到能够提供第二频率f2输出信号的频率合成器的输入。 第二频率通过预定的有理分数与第一频率相关（例如，作为f2 =（M / N）f1）。 合成器包括相位控制单元，该相位控制单元包括加法器，通过该加法器将第一数量N加到每个采样周期到余数，加法器的和输出以模数第二数M运行，例如通过除以M和丢弃 得到余数的结果商。 将具有零和M-1之间的值的余数与前缀信号进行比较，说明性地是M / 2中的最大整数。 如果余数小于预定信号，则向控制系统提供第一逻辑状态控制信号; 否则提供第二逻辑状态信号。 第一和第二逻辑状态之间的交替使得第二频率的M个脉冲对于第一频率的每N个脉冲发生。 由此，响应于第一频率合成第二频率。
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公开(公告)号：US4669116A
公开(公告)日：1987-05-26
申请号：US448418
申请日：1982-12-09
摘要： An echo cancellation circuit is disclosed for use with full-duplex data transmission systems. The echo canceller can operate in spite of time invariant non-linearities in the echo channel or in the implementation of the echo canceller itself (such as in D/A converters). The echo canceller receives an echo signal having linear and non-linear components and includes N linear tap weights for cancelling the non-linear components of that echo signal where M is greater than N but less than 2.sup.N.
摘要翻译： 公开了一种用于全双工数据传输系统的回波消除电路。 回声消除器可以在回波信道中或在回声消除器本身的实现中（如D / A转换器）中的时间不变的非线性运行。 回波消除器接收具有线性和非线性分量的回波信号，并且包括N个线性抽头权重，用于抵消该回波信号的非线性分量，其中M大于N但小于2N。
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公开(公告)号：US4669115A
公开(公告)日：1987-05-26
申请号：US725508
申请日：1985-04-22
CPC分类号： H04B1/586
摘要： An adaptive hybrid circuit for use in a digital telephone switching system is disclosed. The hybrid circuit is adaptive in that it provides cancellation of a far end talker power component in an output signal having both far end talker and near end talker power components. The circuit includes first and second transfer filters for matching loaded and non-loaded subscriber loops, respectively, in the telephone system. The circuit generates a filtered signal representing the difference between loaded and non-loaded subscriber impedances in the telephone system and generates an adaptive control signal responsive to the filtered signal and the output signal such that the far end talker power component is cancelled.
摘要翻译： 公开了一种用于数字电话交换系统的自适应混合电路。 混合电路是自适应的，因为它提供了具有远端讲话者和近端讲话者功率分量的输出信号中的远端讲话者功率分量的消除。 该电路包括分别用于在电话系统中匹配加载和非负载用户环路的第一和第二传输过滤器。 电路产生表示电话系统中的加载用户阻抗和非加载用户阻抗之间的差异的滤波信号，并响应于滤波的信号和输出信号产生自适应控制信号，使得远端讲话者功率分量被取消。
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公开(公告)号：US4407020A
公开(公告)日：1983-09-27
申请号：US180530
申请日：1980-08-25
IPC分类号： H04J3/10
CPC分类号： H04J3/10
摘要： An automatic compensation circuit for use in a digital switching system. The circuit provides automatic compensation for each incoming channel of a pulse amplitude modulated (PAM) input signal. The circuit generates a compensation data word corresponding to the sign of each sample of the input PAM signal and increments or decrements the compensation word depending upon the sign of the previously sampled PAM signal for each channel, thereby providing automatic compensation dependent upon the value of the adjusted data word.
摘要翻译： 一种用于数字交换系统的自动补偿电路。 电路为脉冲幅度调制（PAM）输入信号的每个输入通道提供自动补偿。 电路产生对应于输入PAM信号的每个样本的符号的补偿数据字，并根据每个通道的先前采样的PAM信号的符号递增或递减补偿字，从而根据 调整后的数据字。
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