利索-全球专利检索

  1. 登录
  2. 注册

搜索结果

46 条记录 (耗时 0.043 秒)

    Apparatus and method for generating an AM-compatible digital broadcast waveform
    4.
    发明授权
    Apparatus and method for generating an AM-compatible digital broadcast waveform 失效
    用于产生AM兼容的数字广播波形的装置和方法

    公开(公告)号：US5930687A

    公开(公告)日：1999-07-27

    申请号：US724606

    申请日：1996-09-30

    申请人： Mark J. Dapper ,  Michael J. Geile ,  Barry Walter Carlin

    发明人： Mark J. Dapper ,  Michael J. Geile ,  Barry Walter Carlin

    IPC分类号： H03C3/40 ,  H04H20/36 ,  H03C1/52

    CPC分类号： H03C3/40 ,  H04H20/36 ,  H04H2201/186

    摘要： An apparatus and method for generating a broadcast waveform is provided which, for generating an in-phase component, includes an in-phase digital signal generator; a first filter for filtering the in-phase digital signal; a first digital-to-analog converter for converting the filtered digital signal into a first analog signal; an AM baseband signal generator producing an AM baseband signal; a first summer for summing the first analog and AM baseband signals to produce a composite analog signal; and a first modulator for modulating the composite analog signal with a first carrier signal at a transmission frequency, thus producing a first modulated signal. To provide the quadrature component of the broadcast waveform, the waveform generator includes a quadrature digital signal generator producing a quadrature digital signal; a second digital-to-analog converter for converting the quadrature digital signal into a second analog signal; a second modulator for modulating the second base-band signal with a second carrier signal; and a second summer for summing the first and second modulated signals, thus producing the broadcast waveform. The apparatus improves the signal-to-noise ratio in analog AM receivers, especially at higher frequencies.

    摘要翻译： 提供一种用于产生广播波形的装置和方法，用于产生同相分量包括同相数字信号发生器; 用于对同相数字信号进行滤波的第一滤波器; 第一数模转换器，用于将滤波后的数字信号转换成第一模拟信号; 产生AM基带信号的AM基带信号发生器; 第一个夏天用于求和第一个模拟和AM基带信号以产生复合模拟信号; 以及用于以传输频率用第一载波信号调制复合模拟信号的第一调制器，从而产生第一调制信号。 为了提供广播波形的正交分量，波形发生器包括产生正交数字信号的正交数字信号发生器; 用于将所述正交数字信号转换成第二模拟信号的第二数模转换器; 第二调制器，用第二载波信号调制第二基带信号; 以及第二加法器，用于对第一和第二调制信号进行求和，从而产生广播波形。 该装置提高了模拟AM接收机的信噪比，特别是在较高的频率下。

    Coherent signal detector for AM-compatible digital audio broadcast waveform recovery
    5.
    发明授权
    Coherent signal detector for AM-compatible digital audio broadcast waveform recovery 失效
    相干信号检测器用于AM兼容数字音频广播波形恢复

    公开(公告)号：US5878089A

    公开(公告)日：1999-03-02

    申请号：US803699

    申请日：1997-02-21

    申请人： Mark J. Dapper ,  Barry W. Carlin ,  Michael J. Geile

    发明人： Mark J. Dapper ,  Barry W. Carlin ,  Michael J. Geile

    IPC分类号： H03D3/00 ,  H03D3/24 ,  H03G3/30 ,  H03D3/22

    CPC分类号： H03D3/244 ,  H03D3/009 ,  H03G3/3052

    摘要： A coherent signal detector for extracting analog and digital information from a received AM-compatible digital broadcast waveform is provided. The waveform can have an in-phase component and a quadrature component. The detector can include a down converter for shifting the in-phase and quadrature components in phase, frequency, or both, in response to a phase word, thereby providing a recovered in-phase output and a recovered quadrature output. The signal detector also includes an integration circuit for integrating a portion of the recovered quadrature output over a first preselected time interval, which can be one digital time frame.

    摘要翻译： 提供了一种从接收的AM兼容数字广播波形中提取模拟和数字信息的相干信号检测器。 波形可以具有同相分量和正交分量。 检测器可以包括用于响应于相位字相位，频率或两者同步偏移同相和正交分量的下变频器，由此提供恢复的同相输出和恢复的正交输出。 信号检测器还包括积分电路，用于在第一预选时间间隔内对恢复的正交输出的一部分进行积分，其可以是一个数字时间帧。

    Equalization system for AM compatible digital receiver
    6.
    发明授权
    Equalization system for AM compatible digital receiver 失效
    AM兼容数字接收机的均衡系统

    公开(公告)号：US5559830A

    公开(公告)日：1996-09-24

    申请号：US376986

    申请日：1995-01-23

    申请人： Mark J. Dapper ,  Michael J. Geile ,  Barry W. Carlin

    发明人： Mark J. Dapper ,  Michael J. Geile ,  Barry W. Carlin

    IPC分类号： H04H40/27 ,  H03H7/30

    CPC分类号： H04H40/27 ,  H04H2201/186

    摘要： An equalizer is provided for enhancing the recoverability of digital audio broadcasting signal information. The equalizer receives the AM compatible digital audio broadcasting waveform and stores that waveform as a waveform vector. The equalizer then processes that waveform by multiplying the waveform vector by an equalization vector. This equalization vector comprises a plurality of equalizer coefficients, each of the coefficients initially set to a predetermined value. The equalizer then compares each location of the processed waveform vector with a stored waveform vector. The equalizer selects as the signal that vector location closest to the stored waveform vector. Preferably, the equalizer includes means for updating the equalizer coefficients using the waveform vector, the processed waveform vector, and the stored waveform vector to provide immunity to noise.

    摘要翻译： 提供均衡器以增强数字音频广播信号信息的可恢复性。 均衡器接收AM兼容数字音频广播波形并将该波形存储为波形向量。 然后，均衡器通过将波形矢量乘以均衡矢量来处理该波形。 该均衡矢量包括多个均衡器系数，每个系数初始设定为预定值。 然后，均衡器将经处理的波形向量的每个位置与存储的波形向量进行比较。 均衡器选择最接近存储的波形向量的向量位置的信号。 优选地，均衡器包括用于使用波形向量，经处理的波形向量和存储的波形向量来更新均衡器系数以提供对噪声的抗扰性的装置。