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    Technique for communicating digitally modulated signals over an amplitude-modulation frequency band
    1.
    发明公开
    Technique for communicating digitally modulated signals over an amplitude-modulation frequency band 有权
    Verfahren zurÜbertragung数字调制器Signaleüberein AM-Frequenzband

    公开(公告)号：EP0952696A2

    公开(公告)日：1999-10-27

    申请号：EP99302843.0

    申请日：1999-04-13

    申请人： LUCENT TECHNOLOGIES INC.

    发明人： Chen, Brian ,  Sundberg, Carl-Erik Wilhelm

    IPC分类号： H04L5/02

    CPC分类号： H04L5/023 ,  H04J11/003 ,  H04J11/005 ,  H04L25/03853 ,  H04L27/2646

    摘要： In a communications system implementing an in-band on channel AM (IBOC-AM) (also known as "hybrid IBOC-AM") scheme, digitally modulated signals are transmitted in a 30 kHz digital band centered at an analog host AM carrier frequency f c . The host AM carrier is assigned to the geographic area served by the communications system for AM radio broadcast. It is likely that a similar IBOC-AM scheme is implemented in an adjacent area which is assigned a second analog host AM carrier having a frequency which is either 20 kHz higher or lower than f c . In that case, the transmission of the digitally modulated signals are interfered by a similar transmission in the adjacent area. The interference is known as "second adjacent channel interference." To reduce such interference, selected power profiles in accordance with the invention are used to allocate the relative transmission power to the digitally modulated signals in the digital band.

    摘要翻译： 在实现频带AM（IBOC-AM）（也称为“混合IBOC-AM”）方案的通信系统中，数字调制信号在以模拟主机AM载波频率fc为中心的30kHz数字频带中发送 。 主机AM载波被分配给由AM无线电广播的通信系统服务的地理区域。 在相邻区域中实现类似的IBOC-AM方案很可能被分配有频率高于或低于fc的20kHz的第二模拟主机AM载波。 在这种情况下，数字调制信号的传输被相邻区域中的相似传输干扰。 干扰被称为“第二相邻信道干扰”。 为了减少这样的干扰，使用根据本发明的所选择的功率曲线来将相对发射功率分配给数字频带中的数字调制信号。

    EQUALIZER FOR LIMITED INTERSYMBOL INTERFERENCE
    2.
    发明公开
    EQUALIZER FOR LIMITED INTERSYMBOL INTERFERENCE 审中-公开

    公开(公告)号：EP3376726A1

    公开(公告)日：2018-09-19

    申请号：EP18161315.9

    申请日：2018-03-12

    申请人： Tektronix, Inc.

    发明人： TAN, Kan

    IPC分类号： H04L25/03 ,  G01R13/00

    CPC分类号： H04L7/0331 ,  G01R13/00 ,  H04L1/205 ,  H04L7/0029 ,  H04L7/0087 ,  H04L25/03012 ,  H04L25/03019 ,  H04L25/03853

    摘要： Disclosed is a mechanism for limiting Intersymbol Interference (ISI) when measuring uncorrelated jitter in a test and measurement system. A waveform is obtained that describes a signal. Such waveform may be obtained from memory. A processor then extracts a signal pulse from the waveform. The processor selects a window function based on a shape of the signal pulse. Further, the processor applies the window function to the signal pulse to remove ISI outside a window of the window function while measuring waveform jitter. The window function may be applied by applying the window function to the signal pulse to obtain a target pulse. A linear equalizer is then generated that results in the target pulse when convolved with the signal pulse. The linear equalizer is then applied to the waveform to limit ISI for jitter measurement.

    Méthode itérative de synthèse de filtres numériques de mise en forme d'un signal
    4.
    发明公开
    Méthode itérative de synthèse de filtres numériques de mise en forme d'un signal 有权
    为数字滤波器的用于频谱信号整形的合成迭代方法

    公开(公告)号：EP2884708A1

    公开(公告)日：2015-06-17

    申请号：EP14197049.1

    申请日：2014-12-09

    申请人： Thales

    发明人： Baptiste, François

    IPC分类号： H04L25/03 ,  H03H21/00 ,  H03H17/02

    CPC分类号： H04L25/03057 ,  H04L25/03012 ,  H04L25/03853 ,  H04L25/03885 ,  H04L25/03949 ,  H04L27/01 ,  H04L2025/03611 ,  H04L2025/037

    摘要： Méthode itérative de synthèse de filtres numériques comprenant les étapes suivantes :
    • La génération d'un filtre d'émission (101) destiné à être appliqué à un signal à émettre,
    • La génération d'un filtre de réception (102) destiné à être appliqué à un signal reçu,

    ladite méthode étant caractérisée en ce qu'elle comprend les étapes suivantes exécutées itérativement :
    • La convolution (107) du filtre d'émission et du filtre de réception pour générer un filtre de transmission,
    • La détermination (108) d'un critère représentatif du niveau d'interférence inter-symboles sur ledit filtre de transmission et si le niveau d'interférence inter-symboles est supérieur à un niveau donné,
    • Le calcul d'un filtre égaliseur de l'interférence inter-symboles (110),
    • Le remplacement du filtre d'émission par le filtre d'émission convolué (105) avec le filtre égaliseur ou le remplacement du filtre de réception par le filtre de réception convolué (106) avec le filtre égaliseur.

    Technique for communicating digitally modulated signals over an amplitude-modulation frequency band
    6.
    发明公开
    Technique for communicating digitally modulated signals over an amplitude-modulation frequency band 有权
    用于在一个AM频带发送数字调制信号的方法

    公开(公告)号：EP0952696A3

    公开(公告)日：2003-11-19

    申请号：EP99302843.0

    申请日：1999-04-13

    申请人： LUCENT TECHNOLOGIES INC.

    发明人： Chen, Brian ,  Sundberg, Carl-Erik Wilhelm

    IPC分类号： H04L5/02 ,  H04B7/005 ,  H04L27/26 ,  H04M11/06 ,  H04H1/00

    CPC分类号： H04L5/023 ,  H04J11/003 ,  H04J11/005 ,  H04L25/03853 ,  H04L27/2646

    摘要： In a communications system implementing an in-band on channel AM (IBOC-AM) (also known as "hybrid IBOC-AM") scheme, digitally modulated signals are transmitted in a 30 kHz digital band centered at an analog host AM carrier frequency f c . The host AM carrier is assigned to the geographic area served by the communications system for AM radio broadcast. It is likely that a similar IBOC-AM scheme is implemented in an adjacent area which is assigned a second analog host AM carrier having a frequency which is either 20 kHz higher or lower than f c . In that case, the transmission of the digitally modulated signals are interfered by a similar transmission in the adjacent area. The interference is known as "second adjacent channel interference." To reduce such interference, selected power profiles in accordance with the invention are used to allocate the relative transmission power to the digitally modulated signals in the digital band.

    Precoded waveshaping transmitter
    7.
    发明公开
    Precoded waveshaping transmitter 失效
    威尔康多

    公开(公告)号：EP0673139A2

    公开(公告)日：1995-09-20

    申请号：EP95300990.9

    申请日：1995-02-16

    申请人： ADVANCED MICRO DEVICES INC.

    发明人： Young, David

    IPC分类号： H04L25/49 ,  H04L25/03

    CPC分类号： H04L25/49 ,  H04L25/03853

    摘要： A precoded waveshaping transmitter comprises a synchronous delay line circuit, a transmitter state machine and a differential current digital to analog converter. Through the provision of plurality of precoded staggered time delayed data from the combination of the delay line circuit and transmitter state machine the DAC can provide a predetermined output. In a preferred implementation, a subharmonic frequency can be maintained at least 27dB below the fundamental frequency when the PWT is driven by an all ones Manchester encoded signal.

    摘要翻译： 预编码波形发射机包括同步延迟线电路，发射机状态机和差分电流数模转换器。 通过从延迟线电路和发射机状态机的组合提供多个经预编码的交错时间延迟数据，DAC可以提供预定的输出。 在优选的实施方案中，当PWT由全部曼彻斯特编码信号驱动时，次谐波频率可以保持在低于基频的至少27dB。

    Integrated waveshaping circuit
    10.
    发明公开
    Integrated waveshaping circuit 失效
    集成的波形电路。

    公开(公告)号：EP0607677A3

    公开(公告)日：1997-09-03

    申请号：EP93310017.4

    申请日：1993-12-13

    申请人： NATIONAL SEMICONDUCTOR CORPORATION

    发明人： Segaram, Para K.

    IPC分类号： H04L25/03 ,  H04L25/08

    CPC分类号： H04L25/0286 ,  H03M1/745 ,  H04L25/0272 ,  H04L25/0282 ,  H04L25/03853

    摘要： The waveshaping functions provided by a summing resistor network and filter are performed by a waveshaping circuit that can be integrated with transceiving functions within a single integrated circuit. The waveshaping circuit utilizes the edges of an oscillator signal to generate a series of pairs of logic signals which have a defined timing relationship with respect to an input data signal. Each pair of logic signals is then utilized by a corresponding number of current stages to provide both an incremental portion of an output waveform and an incremental portion of a complementary output waveform. The pair of output waveforms can then be produced by summing together all of the incremental portions of the pair of waveforms.