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1.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
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。
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公开(公告)号：US5559830A
公开(公告)日：1996-09-24
申请号：US376986
申请日：1995-01-23
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。
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3.发明授权Method and apparatus for improving the quality of AM compatible digital broadcast system signals in the presence of distortion 失效用于在存在失真的情况下提高AM兼容的数字广播系统信号的质量的方法和装置
公开(公告)号：US5809065A
公开(公告)日：1998-09-15
申请号：US603768
申请日：1996-02-20
CPC分类号： H04L27/0008 , H03D5/00 , H04H20/36 , H04L1/20 , H04H20/20 , H04H2201/186
摘要： A system and method are provided for reducing perceived distortion in an output audio signal derived from an amplitude modulated compatible digital broadcast signal having an analog portion and a digital portion. The digital portion of this signal is demodulated to produce a demodulated digital signal and the analog portion of the signal is demodulated to produce a demodulated analog signal. The noise in the demodulated digital signal is measured and an estimate of the signal-to-noise ratio is derived. This estimated signal-to-noise ratio is compared with a threshold level which is set at the minimum acceptable signal quality for the digital signal. Based upon the estimated signal-to-noise ratio, a switch directs either the analog derived audio output or the digitally derived audio output as the system output signal.
摘要翻译： 提供了一种系统和方法，用于减少从具有模拟部分和数字部分的幅度调制兼容数字广播信号导出的输出音频信号中的感知失真。 该信号的数字部分被解调以产生解调的数字信号，并且信号的模拟部分被解调以产生解调的模拟信号。 测量解调数字信号中的噪声，得出信噪比的估计。 将该估计的信噪比与对于数字信号设置为最小可接受信号质量的阈值电平进行比较。 基于估计的信噪比，开关将模拟导出的音频输出或数字导出的音频输出指导为系统输出信号。
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4.发明授权AM compatible digital waveform frame timing recovery and frame synchronous power measurement 失效AM兼容数字波形帧定时恢复和帧同步功率测量
公开(公告)号：US5764706A
公开(公告)日：1998-06-09
申请号：US636044
申请日：1996-04-22
CPC分类号： H04H20/36 , H04H20/49 , H04H40/27 , H04L27/2602 , H04L27/2656 , H04L27/2662 , H04L5/023 , H04H2201/186 , H04H2201/20
摘要： In a broadcast system having a complex waveform of digital and analog segments, frame timing is recovered and the frame synchronous power of the digital portion of the composite AM compatible Digital Audio Broadcast (DAB) waveform is measured by examining a portion of the signal. The frame timing necessary for proper demodulation is recovered from the received signal, and a signal power measurement for scaling is provided. The composite AM compatible DAB waveform is produced by a modulation method in which a digital representation of an audio signal is encoded together with an analog amplitude modulated (AM) signal and transmitted simultaneously in the same frequency channel.
摘要翻译： 在具有数字和模拟段的复杂波形的广播系统中，恢复帧定时，并通过检查信号的一部分来测量复合AM兼容数字音频广播（DAB）波形的数字部分的帧同步功率。 从接收信号中恢复正确解调所需的帧定时，并提供用于缩放的信号功率测量。 复合AM兼容DAB波形通过调制方法产生，其中音频信号的数字表示与模拟幅度调制（AM）信号一起编码并在同一频道中同时传输。
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公开(公告)号：US5633896A
公开(公告)日：1997-05-27
申请号：US604276
申请日：1996-02-21
CPC分类号： H04L27/265 , H03D1/2245 , H04H2201/186
摘要： The invention provides a method and apparatus for demodulating a composite AM DAB waveform which contains digitally modulated carriers and which employ (1) a mixer for converting a received signal into two signals (the first of these two signals represents an in-phase component and the second of these two signals represents a quadrature component); (2) two analog-to-digital converters for converting the two signals into digital signals; and (3) two fast Fourier transform elements for extracting data separately from the two digital signals. Complementary digital carrier signals are recovered from the quadrature component, and non-complementary digital carriers are derived from a sum of the complementary data and the output of the in-phase component FFT process. Leakage of the AM signal through a highpass filter is prevented from interfering with the demodulation of the complementary carrier signals' use of separated demodulation channels.
摘要翻译： 本发明提供了一种用于解调包含数字调制载波的复合AM DAB波形的方法和装置，其采用（1）混频器将接收信号转换为两个信号（这两个信号中的第一个表示同相分量， 这两个信号中的第二个表示正交分量）; （2）两个用于将两个信号转换为数字信号的模拟 - 数字转换器; 和（3）用于从两个数字信号分离提取数据的两个快速傅里叶变换元件。 从正交分量中恢复互补数字载波信号，并且从互补数据和同相分量FFT处理的输出之和导出非互补数字载波。 防止AM信号通过高通滤波器的泄漏干扰互补载波信号对分离的解调信道的使用的解调。
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公开(公告)号：US6128334A
公开(公告)日：2000-10-03
申请号：US803714
申请日：1997-02-21
CPC分类号： H04H20/36 , H04H60/14 , H04H2201/186 , H04H2201/70
摘要： The present invention provides for a receiver addressable AM compatible digital broadcast system and method. The digital broadcast signal includes a plurality of digitally modulated signals and an analog signal. A transmitter useable within the system includes a data combiner for generating an aggregate digital data signal, and a waveform generator for forming the digital broadcast signal. A receiver useable within the system comprises a waveform detector for separating the signals and a data parser for separating the digitally modulated signals. The present invention further provides for a method of selectively transmitting data via a digital broadcast signal. The method includes forming the digital broadcast signal from an analog signal and a plurality of digitally modulated signals, transmitting and receiving the digital broadcast signal. The method further includes the steps of separating the analog signal from the digitally modulated signals, separating the digitally modulated signals, comparing a destination identification signal with an identification code, and passing a user defined message signal responsive to the destination identification digital signal corresponding to the identification code.
摘要翻译： 本发明提供一种接收机可寻址AM兼容数字广播系统和方法。 数字广播信号包括多个数字调制信号和模拟信号。 可在系统内使用的发射器包括用于产生聚合数字数据信号的数据组合器和用于形成数字广播信号的波形发生器。 可在系统内使用的接收器包括用于分离信号的波形检测器和用于分离数字调制信号的数据解析器。 本发明还提供了一种经由数字广播信号有选择地发送数据的方法。 该方法包括从模拟信号和多个数字调制信号形成数字广播信号，发送和接收数字广播信号。 该方法还包括以下步骤：将模拟信号与数字调制信号分离，分离数字调制信号，将目的地识别信号与识别码进行比较，以及响应于对应于目的地识别数字信号的用户定义消息信号 识别码。
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公开(公告)号：US5898732A
公开(公告)日：1999-04-27
申请号：US602553
申请日：1996-02-20
CPC分类号： H04L5/023 , H04H20/36 , H04H2201/186
摘要： A service channel is provided for concurrent communication with an amplitude modulated compatible digital broadcast signal. A transmitter receives input program information and input data service and combines the program information and data service to produce composite data. The transmitter generates an over-the-air signal waveform using the composite data. This signal is an amplitude modulated compatible digital broadcast signal. At least one receiver is used in the system to detect the over-the-air signal waveform produced by the transmitter. The receiver parses the composite data into program information and data service. The parsing of this composite data is achieved by using header information provided on each of the input program information and input data service.
摘要翻译： 提供服务信道用于与调幅兼容数字广播信号的并发通信。 发射机接收输入节目信息和输入数据服务，并组合节目信息和数据服务以产生复合数据。 发射机使用复合数据生成空中信号波形。 该信号是调幅兼容的数字广播信号。 在系统中使用至少一个接收机来检测发射机产生的空中信号波形。 接收机将复合数据解析为程序信息和数据服务。 通过使用在每个输入程序信息和输入数据服务上提供的标题信息来实现对该复合数据的解析。
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公开(公告)号：US5588022A
公开(公告)日：1996-12-24
申请号：US206368
申请日：1994-03-07
IPC分类号： H04L27/34 , H03C5/00 , H04B1/04 , H04H20/36 , H04J11/00 , H04L5/02 , H04L27/18 , H04L27/26 , H04L27/36 , H04L27/38 , H04L27/00 , H04L23/02 , H04L27/28
CPC分类号： H04H20/36 , H04B1/04 , H04L27/2602 , H04L5/023 , H04H2201/186
摘要： A broadcasting method for simultaneously broadcasting analog and digital signals in a standard AM broadcasting channel is provided by: broadcasting an amplitude modulated radio frequency signal having a first frequency spectrum, wherein the amplitude modulated radio frequency signal includes a first carrier modulated by an analog program signal; and simultaneously broadcasting a plurality of digitally modulated carrier signals within a bandwidth which encompasses the first frequency spectrum, each of the digitally modulated carrier signals being modulated by a portion of a digital program signal, wherein a first group of the digitally modulated carrier signals lying within the first frequency spectrum are modulated in-quadrature with the first carrier signal, and wherein second and third groups of the digitally modulated carrier signals lie outside of the first frequency spectrum and are modulated both in-phase and in-quadrature with the first carrier signal. Transmitters and receivers which operate in accordance with the above method are also provided.
摘要翻译： 通过以下方式提供在标准AM广播频道中同时广播模拟和数字信号的广播方法：广播具有第一频谱的幅度调制射频信号，其中调幅射频信号包括由模拟节目信号调制的第一载波 ; 并且在包含所述第一频谱的带宽内同时广播多个数字调制载波信号，所述数字调制载波信号中的每一个由数字节目信号的一部分调制，其中位于所述数字调制载波信号中的第一组数字调制载波信号 第一频谱与第一载波信号正交调制，并且其中第二和第三组数字调制载波信号位于第一频谱之外，并且与第一载波信号同相和正交调制 。 还提供了根据上述方法操作的发射机和接收机。
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9.发明授权Method and apparatus for improving the quality of AM compatible digital broadcast system signals in the presence of distortion 失效用于在存在失真的情况下提高AM兼容的数字广播系统信号的质量的方法和装置
公开(公告)号：US5703954A
公开(公告)日：1997-12-30
申请号：US604199
申请日：1996-02-20
CPC分类号： H04H40/18 , H04H20/22 , H04H20/26 , H04H20/33 , H04H2201/186
摘要： A system and method are provided for reducing perceived distortion in an output audio signal derived from an amplitude modulated compatible digital broadcast signal having a monophonic portion and a stereo portion. The stereo portion of this signal is demodulated to produce a demodulated stereo signal and the monophonic portion of the signal is demodulated to produce a demodulated monophonic signal. The noise in the demodulated stereo signal is measured and an estimate of the signal-to-noise ratio is derived. This estimated signal-to-noise ratio is compared with a threshold level which is set at the minimum acceptable signal quality for the stereo signal. Based upon the estimated signal-to-noise ratio, a switch directs either the monophonic derived audio output or the stereo derived audio output as the system output signal.
摘要翻译： 提供了一种系统和方法，用于减少从具有单声道部分和立体声部分的幅度调制兼容数字广播信号导出的输出音频信号中的感知失真。 该信号的立体声部分被解调以产生解调的立体声信号，并且信号的单声道部分被解调以产生解调的单声道信号。 测量解调立体声信号中的噪声，并推导出信噪比的估计。 将该估计的信噪比与对于立体声信号设置为最小可接受信号质量的阈值电平进行比较。 基于估计的信噪比，开关将单声道导出音频输出或立体声导出音频输出指导为系统输出信号。
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公开(公告)号：US5606576A
公开(公告)日：1997-02-25
申请号：US376987
申请日：1995-01-23
摘要： An adaptive mode control system is provided which includes a transmitter including apparatus for inputting format information regarding the waveform structure of an AM compatible digital broadcast signal. The transmitter also includes apparatus for inputting user data such as the information to be broadcast. The transmitter selects the waveform parameters in response to the format information and produces control channel information. The transmitter uses this control channel information in combination with the user data to produce composite data. The transmitter generates an over-the-air signal waveform using the composite data and waveform parameters. Each receiver includes apparatus for detecting the over-the-air signal waveform and composite data generated by the transmitter. The receiver further includes apparatus for parsing the composite data into user data and control channel information. The receiver regenerates the waveform parameters from the control channel information and folds the waveform parameters into the receiver's detection apparatus so that the waveform parameters can reconfigure the receiver for receipt of subsequent transmissions.
摘要翻译： 提供一种自适应模式控制系统，其包括发射机，其包括用于输入关于AM兼容数字广播信号的波形结构的格式信息的装置。 发射机还包括用于输入诸如要广播的信息的用户数据的装置。 变送器根据格式信息选择波形参数，并产生控制信道信息。 发射机使用该控制信道信息与用户数据组合来产生复合数据。 发射机使用复合数据和波形参数生成空中信号波形。 每个接收机包括用于检测由空中信号波形和由发射机产生的复合数据的装置。 接收机还包括用于将复合数据解析为用户数据和控制信道信息的装置。 接收器从控制信道信息重新产生波形参数并将波形参数折叠到接收机的检测装置中，使得波形参数可以重新配置接收机以接收后续传输。
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