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1.发明授权Rapid-update adaptive channel-equalization filtering for digital radio receivers, such as HDTV receivers 失效用于数字无线电接收机（如HDTV接收机）的快速更新自适应信道均衡滤波
公开(公告)号：US5648987A
公开(公告)日：1997-07-15
申请号：US216936
申请日：1994-03-24
IPC分类号： H03H15/00 , H03H17/00 , H03H21/00 , H04B3/04 , H04B7/005 , H04L7/02 , H04L7/08 , H04L25/03 , H04N5/21 , H04N7/015 , H04N7/08 , H04N7/081 , H04L27/01
CPC分类号： H04N5/211 , H04L25/03038 , H04L7/08
摘要： In response to a received carrier wave modulated in accordance with a digital signal, a digital radio receiver recovers in digital form a modulating signal that is at times subject to undesirable amounts of multipath distortion. This recovered modulating signal is applied as respective input signals to first and second finite-impulse-response (FIR) filters, each of an N-tap type, the taps of which are adaptively weighted. The first FIR filter responds to the modulating signal to supply an output signal in which multipath distortion is suppressed. The second FIR filter responds to the modulating signal to generate corrections for the tap weights of the first FIR filter, which corrections are generated more rapidly than can be done with a microprocessor of the type commonly known as a "digital signal processor" or "DSP". A digital comparator compares samples of the first FIR filter response to corresponding samples of an ideal response, thereby to generate updated tap weights for the second FIR filter.
摘要翻译： 响应于根据数字信号调制的接收载波，数字无线电接收机以数字形式恢复有时受到不希望量的多径失真的调制信号。 该恢复的调制信号作为相应的输入信号施加到第一和第二有限脉冲响应（FIR）滤波器，每个N抽头类型，其抽头被自适应加权。 第一FIR滤波器响应调制信号以提供抑制多径失真的输出信号。 第二FIR滤波器响应于调制信号以产生第一FIR滤波器的抽头权重的校正，该校正比通常称为“数字信号处理器”或“DSP”的微处理器更快地产生 “。 数字比较器将第一FIR滤波器响应的样本与理想响应的对应样本进行比较，从而为第二FIR滤波器生成更新的抽头权重。
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2.发明授权Repetitive-PN1023-sequence echo-cancellation reference signal for single-carrier digital television broadcast systems 失效针对单载波数字电视广播系统的重复PN1023序列回波消除参考信号公开(公告)号：US06768517B2
公开(公告)日：2004-07-27
申请号：US09903079
申请日：2001-07-11
IPC分类号： H04N521
CPC分类号： H04L25/03987 , H04L1/0057 , H04L1/0059 , H04L1/0065 , H04L1/0071 , H04L1/0083 , H04L25/03006 , H04L2025/03375 , H04L2025/03605 , H04L2025/03789 , H04N5/211 , H04N5/4401
摘要： DTV signals transmitted over the air with a symbol rate of around 10.76 million samples per second include echo-cancellation reference (ECR) signals each of which includes or essentially consists of a repetitive-PN1023 sequence with baud-rate symbols, which repetitive-PN1023 sequence incorporates a number of consecutive data-segment synchronization signals. Receivers for these DTV signals respond to these ECR signals to generate initial weighting coefficients for adaptive filters used for channel equalization and echo suppression. The initial weighting coefficients are calculated from a cepstrum extracted from the repetitive-PN1023 sequence ECR signal by DFT methods or with a PN1023 auto-correlation match filter.
摘要翻译： 通过空中传输的DTV信号具有每秒大约1076万个样本的符号率，包括回波消除参考（ECR）信号，每个信号包括或基本上由具有波特率符号的重复PN1023序列组成，该重复PN1023序列 并入了多个连续的数据段同步信号。 用于这些DTV信号的接收机响应于这些ECR信号以产生用于信道均衡和回波抑制的自适应滤波器的初始加权系数。 通过DFT方法或PN1023自相关匹配滤波器从重复PN1023序列ECR信号提取的倒频谱计算初始加权系数。
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3.发明授权Equalizing intermediate-frequency signals before demodulating them in a digital television receiver 有权在将数字电视接收机解调之前对中频信号进行均衡公开(公告)号：US06573948B1
公开(公告)日：2003-06-03
申请号：US09603376
申请日：2000-06-26
申请人： Allen Le Roy Limberg
发明人： Allen Le Roy Limberg
IPC分类号： H04N521
CPC分类号： H04L27/01 , H04L25/03987 , H04L2025/03382 , H04N5/211 , H04N5/4401
摘要： Adaptive passband equalization filtering comprises in addition to a non-iterative portion, an iterative filtering portion to suppress longer-delayed post-ghosts. This iterative filtering portion differs from that in previous adaptive passband equalization filtering, in which the estimates of transmitted symbols are converted to VSB signal and the feedback signal for the iterative filtering is generated as a weighted summation of successive samples of the VSB signal. Instead, a weighted summation of successive estimates of transmitted symbols is converted to VSB signal to supply the feedback signal for the iterative filtering. Since the conversion to VSB signal is done immediately before the feedback signal is combined with the feedforward signal to generate the passband equalization filtering response that is demodulated, the carrier wave of the feedback signal is currently determined, rather than having been determined in the past. This avoids “ghost iteration with inversion” in the adaptive passband equalization filtering response.
摘要翻译： 自适应通带均衡滤波除了非迭代部分之外还包括迭代滤波部分，以抑制较长延迟的后重影。 该迭代滤波部分与先前的自适应通带均衡滤波中的不同之处在于，其中传输符号的估计被转换为VSB信号，并且生成用于迭代滤波的反馈信号作为VSB信号的连续采样的加权求和。 相反，传输符号的连续估计的加权求和被转换为VSB信号以提供用于迭代滤波的反馈信号。 由于在反馈信号与前馈信号组合之前立即进行到VSB信号的转换，以产生被解调的通带均衡滤波响应，所以反馈信号的载波当前被确定，而不是过去已经确定。 这避免了自适应通带均衡滤波响应中的“反转幽灵迭代”。
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4.发明授权Digital modulation signal receiver with adaptive channel equalization employing discrete fourier transforms 失效具有自适应信道均衡的数字调制信号接收机采用离散傅里叶变换公开(公告)号：US06975689B1
公开(公告)日：2005-12-13
申请号：US09823500
申请日：2001-03-30
CPC分类号： H04L27/02 , H04L25/03159 , H04L2025/03382 , H04N5/211
摘要： Techniques for calculating the system characteristic of the adaptive filtering used for equalization and echo-suppression in a digital communications receiver, such as one used for receiving over-the-air broadcast digital television signal, are described. In these techniques, the system characteristic of the adaptive filtering is calculated from the discrete Fourier transform of successive portions of the input signal supplied to the adaptive filtering and from the discrete Fourier transform of corresponding portions of the transmitted signal, as estimated in the receiver. Receivers for implementing these techniques in various ways are also disclosed.
摘要翻译： 描述用于计算用于数字通信接收机（例如用于接收空中广播数字电视信号的数字通信接收机）中的均衡和回波抑制的自适应滤波的系统特性的技术。 在这些技术中，自适应滤波的系统特性是从提供给自适应滤波的输入信号的连续部分的离散傅立叶变换和从发射信号的对应部分的离散付里叶变换中算出的。 还公开了以各种方式实现这些技术的接收机。
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公开(公告)号：US10601624B2
公开(公告)日：2020-03-24
申请号：US16217120
申请日：2018-12-12
申请人： Allen Le Roy Limberg
发明人： Allen Le Roy Limberg
摘要： Transmitting apparatus and receiving apparatus for communication systems use coded orthogonal frequency-division multiplexed (COFDM) dual-subcarrier-modulation (DCM) signals. The same coded data is mapped both to COFDM subcarriers located in the lower-frequency half spectrum of the DCM signal and to COFDM subcarriers located in its upper-frequency half spectrum. Symbol constellation mappings of COFDM subcarriers in those half spectra preferably employ labeling diversity providing peak-to-average power ratio (PAPR) of the COFDM DCM signals substantially reduced from PAPR of double-sideband COFDM signals.
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公开(公告)号：US20200028725A1
公开(公告)日：2020-01-23
申请号：US16217120
申请日：2018-12-12
申请人： Allen Le Roy Limberg
发明人： Allen Le Roy Limberg
IPC分类号： H04L27/26
摘要： Transmitting apparatus and receiving apparatus for communication systems use coded orthogonal frequency-division multiplexed (COFDM) dual-subcarrier-modulation (DCM) signals. The same coded data is mapped both to COFDM subcarriers located in the lower-frequency half spectrum of the DCM signal and to COFDM subcarriers located in its upper-frequency half spectrum. Symbol constellation mappings of COFDM subcarriers in those half spectra preferably employ labeling diversity providing peak-to-average power ratio (PAPR) of the COFDM DCM signals substantially reduced from PAPR of double-sideband COFDM signals.
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公开(公告)号：US07133082B2
公开(公告)日：2006-11-07
申请号：US09757019
申请日：2001-01-09
申请人： Allen Le Roy Limberg
发明人： Allen Le Roy Limberg
IPC分类号： H04N5/44
CPC分类号： H04N5/4446 , H04N5/4401 , H04N7/106 , H04N21/40 , H04N21/414 , H04N21/426 , H04N21/4436
摘要： An outdoor-antenna digital television receiver system has an electrically controlled remote tuner located close to the antenna. In response to a remote control signal, the remote tuner selects a particular radio-frequency digital television signal to be received, converts that RF DTV signal to an intermediate-frequency digital television signal of prescribed carrier frequency, and drives a downlead transmission line, preferably a coaxial cable. Indoors, the downlead transmission line is provided with an echo-free termination This echo-free termination may be in a “set-top” box that includes a frequency up-conveter that converts the IF DTV signal back to an RF DTV signal for reception by a conventional digital television receiver. Alternatively, the echo-free termination may be in a special DTV receiver without a local tuner. In such a special DTV receiver the IF DTV signal developed across the echo-free termination is supplied to circuitry for demodulation and analog-to-digital conversion, which circuitry supplies digitized baseband DTV signal.
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公开(公告)号：US07050491B2
公开(公告)日：2006-05-23
申请号：US10271386
申请日：2002-10-15
CPC分类号： H04L25/0212 , H04L2025/03382 , H04L2025/03445 , H04N5/211 , H04N5/4401
摘要： An adaptive equalizer for amplitude-modulation (AM) signal received by over-the-air radio transmission comprises feed-forward finite-impulse-response (FIR) filtering and further comprises infinite-impulse-response (IIR) filtering for feeding back decisions. The echo content of baseband signal demodulated from the AM signal is measured for initially determining the reception channel impulse response (CIR) in the time-domain. Thereafter, the CIR is updated by decision feedback. Periodically, the CIR is normalized with respect to the strength of a cursor component thereof. The strengths of longer-delay post-echoes in the normalized CIR are used to determine the weighting coefficients of the IIR filtering, which suppresses the longer-delay post-echoes. The pre-echo and short-delay post-echo portion of the normalized CIR is convolved with the normalized CIR to generate a synthetic normalized CIR. The strengths of pre-echoes and short-delay post-echoes in the synthetic normalized CIR are used to determine the weighting coefficients of the feed-forward FIR filtering, which suppresses the pre-echoes and short-delay post-echoes.
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9.发明授权Ghost cancellation reference signals for broadcast digital television signal receivers and receivers for utilizing them 失效用于广播数字电视信号接收机和接收机的重影消除参考信号用于利用它们公开(公告)号：US06816204B2
公开(公告)日：2004-11-09
申请号：US09765019
申请日：2001-01-18
申请人： Allen Le Roy Limberg
发明人： Allen Le Roy Limberg
IPC分类号： H04N521
CPC分类号： H04N5/211 , H04L2025/03375 , H04L2025/0349 , H04L2025/03617 , H04L2025/03789 , H04L2025/03796
摘要： Broadcast DTV signals are improved by including in each of their successive data fields a training signal for the adaptive channel-equalization and echo-cancellation filtering in receivers. The training signal in each data field includes a prescribed number of cycles of a particular pseudo-random noise sequence extending over a plurality of data segments to provide a training signal for the adaptive filtering that is of longer duration than one of said data segments. Each data segment in each data field begins with a data segment synchronizing sequence, and the training signals incorporate some of these data segment synchronizing sequences within themselves. Receivers are described that initialize the parameters of the adaptive filtering using discrete Fourier transform calculations on the training signal, and receivers are described that initialize the parameters of the adaptive filtering using the results of match filtering for the particular pseudo-random noise sequence.
摘要翻译： 通过在每个相继的数据域中包括用于接收机中的自适应信道均衡和回波消除滤波的训练信号来改善广播DTV信号。 每个数据字段中的训练信号包括在多个数据段上延伸的特定伪随机噪声序列的规定数量的周期，以提供比所述数据段之一长的持续时间的自适应滤波的训练信号。 每个数据字段中的每个数据段以数据段同步序列开头，并且训练信号在其内部并入其中的这些数据段同步序列。 描述了接收机，其使用离散付里叶变换计算对训练信号初始化自适应滤波的参数，并且描述了使用针对特定伪随机噪声序列的匹配滤波的结果来初始化自适应滤波的参数的接收机。
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