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41.发明申请APPARATUS AND METHOD FOR IMPROVING OFDM RECEIVER PERFORMANCE IN THE PRESENCE OF NARROWBAND INTERFERERS 有权用于改善窄带干扰器存在的OFDM接收机性能的装置和方法公开(公告)号：US20140064419A1
公开(公告)日：2014-03-06
申请号：US13596993
申请日：2012-08-28
IPC分类号： H04B1/12
CPC分类号： H04L27/265 , H04L27/2657 , H04L27/2688 , H04L27/2691
摘要： In an Orthogonal Frequency Division Multiplex (“OFDM”) system, the problem of an interferer reducing the signal-to-noise ratio of a signal can be mitigated by generating an interferer-correction signal and subtracting it from the signal to be processed. The amplitude, frequency and phase of the interferences are determined first. The frequency is estimated by averaging the squared-magnitude of multiple FFTs of the incoming signal and then locating the spectral peaks. The phase and amplitude may be estimated from this FFT outputs or through a process of correlation in the time domain. The interferer-correction signal is generated from the estimated amplitude, frequency, and phase. The correction to be subtracted from the main signal in order to reduce the effect of the interference may be generated in the time or frequency domain. The subtraction of the correction may also be implemented in the time or frequency domains.
摘要翻译： 在正交频分复用（“OFDM”）系统中，可以通过产生干扰校正信号并从要处理的信号中减去干扰源来减少信号的信噪比的问题。 首先确定干扰的幅度，频率和相位。 通过对输入信号的多个FFT的平方幅度进行平均，然后定位频谱峰值来估计频率。 可以从该FFT输出或通过时域中的相关过程来估计相位和幅度。 从估计的幅度，频率和相位产生干扰校正信号。 可以在时域或频域中产生要从主信号中减去以减少干扰的影响的校正。 校正的减法也可以在时域或频域中实现。
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42.发明申请SYSTEMS AND METHODS FOR IMPLEMENTING PEAK-TO-AVERAGE POWER RATIO REDUCTION FOR OFDMA MODULATION 有权用于实施OFDMA调制的峰值平均功率比减少的系统和方法公开(公告)号：US20140169188A1
公开(公告)日：2014-06-19
申请号：US13716534
申请日：2012-12-17
IPC分类号： H04B7/04
CPC分类号： H04L27/2614 , H04L5/0044
摘要： A system and method are provided for implementing a peak-to-average power ratio (PAPR) reduction scheme for Orthogonal Frequency-Division Multiple Access (OFDMA) modulation. A unique PAPR reduction scheme for OFDMA modulation for systems operated according to a DOCSIS standard achieves results similar to those attributable to tone reservation schemes in a manner that does not negatively affect an amount of available data capacity, particularly in implementations with limited numbers of subcarriers. The disclosed systems and methods are particularly adaptable to next generation cable gateways and/or next generation cable modems. These next generation cable gateways and/or cable modems may find particular utility in advanced hybrid fiber/coaxial cable systems. The adaptable cable gateways/modems may include a cable gateway system-on-chip (SOC) configuration. The disclosed schemes may be applicable to OFDM modulation. For OFDM, however, the known tone reservation algorithms also may be employed.
摘要翻译： 提供了一种用于实现正交频分多址（OFDMA）调制的峰均功率比（PAPR）降低方案的系统和方法。 用于根据DOCSIS标准操作的系统的OFDMA调制的独特的PAPR降低方案实现了类似于对于音调预留方案的结果的结果，其结果不会不利地影响可用数据容量的数量，特别是在具有有限数目的子载波的实现中。 所公开的系统和方法特别适用于下一代电缆网关和/或下一代电缆调制解调器。 这些下一代电缆网关和/或电缆调制解调器可以在先进的混合光纤/同轴电缆系统中发现特定的用途。 可适应性的电缆网关/调制解调器可以包括电缆网关片上系统（SOC）配置。 所公开的方案可以适用于OFDM调制。 然而，对于OFDM，也可以采用已知的音调预留算法。
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公开(公告)号：US20140119420A1
公开(公告)日：2014-05-01
申请号：US13661817
申请日：2012-10-26
CPC分类号： H04L27/38 , H04L25/067 , H04L27/2649
摘要： Methods and systems to mitigate impulse interference in an OFDM QAM signal. A per-symbol noise measure, or quality measure (QM) is computed for a symbol k as a MSE of distances between carriers in the symbol and points of corresponding QAM constellations. MSE(k) is averaged over multiple symbols to compute a background signal QM, AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a moderate amount, symbol k may be moderately affected by impulse interference, and per-carrier SNR estimates are downgraded for all data carriers in symbol k, prior to LLR computation. SNR downgrading may be linear or step-wise based on an extent to which MSE(k) exceeds AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a significant amount, symbol k may be significantly affected by impulse interference, and LLRs may be set to indicate that all data carriers are erased in symbol k.
摘要翻译： 减少OFDM QAM信号脉冲干扰的方法和系统。 针对符号k计算每符号噪声测量或质量测量（QM），作为符号中的载波与相应QAM星座的点之间的距离的MSE。 MSE（k）在多个符号之间进行平均以计算背景信号QM，AVG_MSE（k）。 如果MSE（k）超过AVG_MSE（k）中等量，则符号k可能受脉冲干扰的适度影响，并且在LLR计算之前，符号k中的所有数据载波的每载波SNR估计被降级。 基于MSE（k）超过AVG_MSE（k）的程度，SNR降级可以是线性的或逐步的。 如果MSE（k）超过AVG_MSE（k）大量，则符号k可能受脉冲干扰的显着影响，并且可以将LLR设置为指示所有数据载体在符号k中被擦除。
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公开(公告)号：US08532113B2
公开(公告)日：2013-09-10
申请号：US13245128
申请日：2011-09-26
IPC分类号： H04J3/06
CPC分类号： H04N21/435 , H04H40/18 , H04L47/14 , H04L47/23 , H04L47/30 , H04L47/32 , H04L47/34 , H04L49/90 , H04N21/235 , H04N21/4382 , H04N21/442
摘要： Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
摘要翻译： 本文描述了用于在宽带和窄带环境中接收和处理多频带信号的方法的实施例。 可以描述和要求保护其他实施例。
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公开(公告)号：US20100150180A1
公开(公告)日：2010-06-17
申请号：US12316876
申请日：2008-12-16
IPC分类号： H04J3/06
CPC分类号： H04N21/435 , H04H40/18 , H04L47/14 , H04L47/23 , H04L47/30 , H04L47/32 , H04L47/34 , H04L49/90 , H04N21/235 , H04N21/4382 , H04N21/442
摘要： Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
摘要翻译： 本文描述了用于在宽带和窄带环境中接收和处理多频带信号的方法的实施例。 可以描述和要求保护其他实施例。
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公开(公告)号：US20090086841A1
公开(公告)日：2009-04-02
申请号：US11904813
申请日：2007-09-28
IPC分类号： H04L27/28
CPC分类号： H04L25/0242 , H04L27/2655 , H04L27/2659 , H04L27/266 , H04L27/2663 , H04L27/2665
摘要： In one embodiment of the invention, a Fourier transform unit convert a unsynchronized received through multiple antennas to a frequency domain. Also, a spectrum estimation unit determines a power spectrum for the unsynchronized data. A notch filter removes data within a frequency band from additional unsynchronized data based on the power spectrum. A synchronization unit synchronizes the notch filtered data and a noise estimation unit determines a noise covariance matrix between the synchronized data received from multiple antennas. In addition, an equalization unit performs channel equalization on the synchronized data based on the noise covariance matrix.
摘要翻译： 在本发明的一个实施例中，傅立叶变换单元将通过多个天线的未同步接收转换为频域。 此外，频谱估计单元确定用于非同步数据的功率谱。 陷波滤波器基于功率谱从附加的非同步数据中去除频带内的数据。 同步单元同步陷波滤波数据，并且噪声估计单元确定从多个天线接收的同步数据之间的噪声协方差矩阵。 此外，均衡单元基于噪声协方差矩阵对同步数据执行信道均衡。
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47.发明授权Apparatus and method for improving OFDM receiver performance in the presence of narrowband interferers 有权在存在窄带干扰的情况下改善OFDM接收机性能的装置和方法公开(公告)号：US09106497B2
公开(公告)日：2015-08-11
申请号：US13596993
申请日：2012-08-28
CPC分类号： H04L27/265 , H04L27/2657 , H04L27/2688 , H04L27/2691
摘要： In an Orthogonal Frequency Division Multiplex (“OFDM”) system, the problem of an interferer reducing the signal-to-noise ratio of a signal can be mitigated by generating an interferer-correction signal and subtracting it from the signal to be processed. The amplitude, frequency and phase of the interferences are determined first. The frequency is estimated by averaging the squared-magnitude of multiple FFTs of the incoming signal and then locating the spectral peaks. The phase and amplitude may be estimated from this FFT outputs or through a process of correlation in the time domain. The interferer-correction signal is generated from the estimated amplitude, frequency, and phase. The correction to be subtracted from the main signal in order to reduce the effect of the interference may be generated in the time or frequency domain. The subtraction of the correction may also be implemented in the time or frequency domains.
摘要翻译： 在正交频分复用（“OFDM”）系统中，可以通过产生干扰校正信号并从要处理的信号中减去干扰源来减少信号的信噪比的问题。 首先确定干扰的幅度，频率和相位。 通过对输入信号的多个FFT的平方幅度进行平均，然后定位频谱峰值来估计频率。 可以从该FFT输出或通过时域中的相关过程来估计相位和幅度。 从估计的幅度，频率和相位产生干扰校正信号。 可以在时域或频域中产生要从主信号中减去以减少干扰的影响的校正。 校正的减法也可以在时域或频域中实现。
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48.发明授权Orthogonal frequency division multiplex (OFDM) demodulator with improved cyclic ambiguity resolution 有权具有改进的循环模糊度分辨率的正交频分复用（OFDM）解调器公开(公告)号：US08938015B2
公开(公告)日：2015-01-20
申请号：US13997706
申请日：2012-03-15
CPC分类号： H04L27/22 , H04L25/03159 , H04L27/01 , H04L27/26 , H04L27/2665 , H04L27/2672 , H04L27/2675 , H04L27/2679 , H04L27/2695
摘要： A system according to one embodiment includes a demodulator configured to receive an OFDM modulated signal over a channel, the signal including a sequence of symbols, each of the symbols including one or more pilot carriers and one or more data carriers; a time filtering and interpolation circuit coupled to the demodulator, the time filtering and interpolation circuit configured to estimate the frequency response of the channel based on time filtering and interpolation of the pilot carriers; a phase slope correction circuit configured to apply each of a plurality of phase slope corrections to the frequency response and to the data carriers; a frequency filtering and interpolation circuit configured to calculate frequency response estimates of the channel at data carrier frequencies based on frequency filtering and interpolation of the phase slope corrected frequency response; an equalization circuit configured to equalize the phase slope corrected data carriers based on the calculated frequency response estimates; an error calculation circuit configure to calculate the mean square error between the equalized data carriers and a nearest QAM constellation point; and an iterative phase slope optimization circuit configured to select the phase slope correction associated with the minimum of the mean square errors, wherein the selected phase slope resolves the cyclic ambiguity.
摘要翻译： 根据一个实施例的系统包括：解调器，被配置为通过信道接收OFDM调制信号，所述信号包括符号序列，每个符号包括一个或多个导频载波和一个或多个数据载波; 耦合到解调器的时间滤波和内插电路，所述时间滤波和内插电路被配置为基于导频载波的时间滤波和内插来估计信道的频率响应; 相位斜率校正电路，被配置为对频率响应和数据载波施加多个相位斜率校正中的每一个; 频率滤波和内插电路，被配置为基于频率滤波和相位斜率校正频率响应的内插来计算数据载波频率处的信道的频率响应估计; 均衡电路，被配置为基于所计算的频率响应估计来均衡相位斜率校正数据载波; 误差计算电路，用于计算均衡数据载波与最近的QAM星座点之间的均方误差; 以及迭代相位斜率优化电路，被配置为选择与所述均方误差的最小值相关联的相位斜率校正，其中所选择的相位斜率解决所述循环模糊度。
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公开(公告)号：US08897412B2
公开(公告)日：2014-11-25
申请号：US13714530
申请日：2012-12-14
CPC分类号： H04L27/01 , H04L27/2647 , H04L27/3836 , H04L2027/0038 , H04L2027/0087
摘要： An approach is provided to mitigate phase noise by correcting common phase error and inter-carrier-interference in a received signal. The approach involves determining a received signal includes phase noise comprising at least a common phase error component and an inter-carrier-interference component. The approach also involves causing the common phase error to be corrected based on one or more pilot carriers. The approach further involves causing an estimate of a main signal component to be subtracted from the one or more pilot carriers. The approach additionally involves determining a sequence of estimated coefficients of a multiplicative phase noise sequence. The approach also involves causing the inter-carrier-inference to be corrected by processing the multiplicative phase noise sequence using the sequence of estimated coefficients. The approach further involves causing an equalized data signal to be output based on the corrected common phase error and the corrected inter-carrier-interference.
摘要翻译： 提供了一种通过校正接收信号中的公共相位误差和载波间干扰来减轻相位噪声的方法。 该方法包括确定接收信号包括至少包括公共相位误差分量和载波间干扰分量的相位噪声。 该方法还涉及基于一个或多个导频载波来校正公共相位误差。 该方法还包括导致从一个或多个导频载波减去主信号分量的估计。 该方法还涉及确定乘法相位噪声序列的估计系数序列。 该方法还涉及通过使用估计系数的序列处理乘法相位噪声序列来使得载波间推理被校正。 该方法进一步包括使得基于校正的公共相位误差和校正的载波间干扰来输出均衡的数据信号。
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公开(公告)号：US08340222B2
公开(公告)日：2012-12-25
申请号：US12647060
申请日：2009-12-24
CPC分类号： H04L25/0224 , H04L25/0204 , H04L25/0212 , H04L25/022 , H04L27/2665 , H04L27/2675 , H04L27/2695
摘要： Methods and systems to resolve the cyclic time ambiguity of a scattered pilot based channel impulse response, including to determine a channel impulse response from a combination of scattered pilots and encoded parameters, such as L1-pre signaling within P2 symbols of a terrestrial digital video broadcast (DVD) in a single frequency network (SFN), and including to re-use a corresponding window time to track the channel impulse response in the absence of encoded parameters. Methods and systems disclosed herein may be implemented with respect to channel acquisition and tracking, including adjusting a Fast Fourier Transform trigger point to reduce inter-symbol interference.
摘要翻译： 解决基于分散导频的信道脉冲响应的循环时间模糊度的方法和系统，包括从散射导频和编码参数的组合确定信道脉冲响应，例如地面数字视频广播的P2符号内的L1预信令 （DVD），并且包括在没有编码参数的情况下重新使用相应的窗口时间来跟踪信道脉冲响应。 本文公开的方法和系统可以相对于信道获取和跟踪来实现，包括调整快速傅里叶变换触发点以减少符号间干扰。
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