公开(公告)号：US08416866B1

公开(公告)日：2013-04-09

申请号：US12512273

申请日：2009-07-30

申请人： Hao-Ren Cheng ,  Kuang-Chung Ou ,  William J McFarland

发明人： Hao-Ren Cheng ,  Kuang-Chung Ou ,  William J McFarland

IPC分类号： H04K1/10

CPC分类号： H04L27/2675 ,  H04L25/0204 ,  H04L25/0224 ,  H04L25/03012 ,  H04L27/2657 ,  H04L27/2695 ,  H04L2025/03414 ,  H04L2025/03636

摘要： This disclosure is directed to systems and methods that compensate for a phase change that results from a change in RF gain, a “phase glitch,” that would otherwise degrade the performance of a multiple sub-carrier communication system, such as OFDM. Pilot symbols are used to estimate the phase change, allowing the pilot and data symbols to be compensated by the estimated phase change. Preferably, the compensated pilots are used to per form a second iteration of phase change estimation that determines residual phase glitch. Thus, following the second estimation of phase change, data symbols can be compensated for the estimated residual phase change.

摘要翻译： 该公开内容涉及补偿由增益（即相位毛刺）引起的相位变化的系统和方法，否则会降低诸如OFDM的多子载波通信系统的性能。 导频符号用于估计相位变化，允许通过估计的相位变化来补偿导频和数据符号。 优选地，补偿导频用于形成确定剩余相位毛刺的相位变化估计的第二迭代。 因此，在相位改变的第二估计之后，可以对估计的残余相位变化补偿数据符号。

公开(公告)号：US08385438B1

公开(公告)日：2013-02-26

申请号：US12365726

申请日：2009-02-04

申请人： Hao-Ren Cheng ,  Gaspar Lee

发明人： Hao-Ren Cheng ,  Gaspar Lee

IPC分类号： H04K1/10

CPC分类号： H04L27/2665 ,  H04L27/2671 ,  H04L27/2695

摘要： A system and method are disclosed to synchronize adaptively a transform window in a multiple sub-carrier communication system based on analysis of a time domain channel impulse response. A set of frequency domain channel estimates, derived from received and one-dimensional Wiener filter interpolated channel estimates, are transformed into a time domain channel impulse response estimate containing multiple, repeated constituent responses. Each order of the constituent responses in the time domain channel impulse response estimate is associated with a two-dimensional Wiener interpolation filter. The set of two-dimensional Wiener interpolation filters generate interpolated channel estimates to compare with received channel estimates to determine a best channel impulse response order of the constituent responses. The transform window is adaptively updated using the best channel impulse response order.

摘要翻译： 公开了一种系统和方法，用于基于时域信道脉冲响应的分析来自适应同步多子载波通信系统中的变换窗口。 从接收的和一维维纳滤波器内插的信道估计导出的一组频域信道估计被转换成包含多个重复的组成响应的时域信道脉冲响应估计。 时域信道脉冲响应估计中的组成响应的每个顺序与二维维纳插值滤波器相关联。 该组二维维纳插值滤波器产生内插信道估计以与接收到的信道估计进行比较，以确定组成响应的最佳信道脉冲响应顺序。 使用最佳信道脉冲响应顺序自适应地更新变换窗口。

公开(公告)号：US08335284B1

公开(公告)日：2012-12-18

申请号：US12398952

申请日：2009-03-05

申请人： Gaspar Lee ,  Hao-Ren Cheng ,  Chih-Yuan Chu ,  Kuang-Chung Ou

发明人： Gaspar Lee ,  Hao-Ren Cheng ,  Chih-Yuan Chu ,  Kuang-Chung Ou

IPC分类号： H03D1/04

CPC分类号： H04L25/0204 ,  H04L25/0232 ,  H04L25/0242

摘要： An apparatus and method in a multiple sub-carrier digital communication receiver for reducing inter-channel interference (ICI) includes a channel estimation block for calculating channel estimates, an interpolation block for calculating interpolated channel estimates, and an ICI reduction block for calculating ICI reduced receive symbols. Channel estimates are calculated based on receive symbols or ICI reduced receive symbols using pre-determined transmit symbols. Interpolated channel estimates are calculated by Wiener filter interpolation of a set of channel estimates. ICI estimates are calculated based on a set of interpolated channel estimates and either receive symbols or ICI reduced receive symbols. ICI reduced receive symbols are generated by subtracting ICI estimates from receive symbols.

摘要翻译： 用于减少信道间干扰（ICI）的多子载波数字通信接收机中的装置和方法包括：用于计算信道估计的信道估计块，用于计算内插信道估计的内插块和用于计算ICI减小的ICI减少块 接收符号。 基于使用预定发送符号的接收符号或ICI缩减的接收符号来计算信道估计。 通过一组信道估计的维纳滤波器插值来计算内插信道估计。 基于一组内插信道估计和接收符号或ICI缩减的接收符号来计算ICI估计。 通过从接收符号中减去ICI估计来产生ICI缩减的接收符号。

公开(公告)号：US20120050096A1

公开(公告)日：2012-03-01

申请号：US12870533

申请日：2010-08-27

申请人： Hao-Ren Cheng ,  Qinfang Sun ,  Hao Zhou ,  Gaspar Lee

发明人： Hao-Ren Cheng ,  Qinfang Sun ,  Hao Zhou ,  Gaspar Lee

IPC分类号： G01S19/42

CPC分类号： G01S19/423

摘要： A method of determining a bit boundary of a GLONASS string is provided. In this method, a global position receiver can remove the meander sequence from bits of a GLONASS signal. After removing the meander sequence, time averages of bit energies for 20 possible (consecutive) bit boundary positions can be computed. At this point, the receiver can select a position from the 20 possible bit boundary positions that maximizes bit energy. A maximum accumulated value at this position as well as offset accumulated values at 5 ms and 15 ms offset from the position can be determined. Then, the receiver can determine whether a ratio of at least one of the offset accumulated values to the maximum accumulated value meets a predetermined condition. When the ratio meets the predetermined condition, the receiver can output the position as the bit boundary of the GLONASS string.

摘要翻译： 提供了一种确定GLONASS字符串的位边界的方法。 在该方法中，全局位置接收器可以从GLONASS信号的位中去除曲折序列。 在去除曲折序列之后，可以计算20个可能（连续）位边界位置的位能量的时间平均值。 此时，接收器可以从最大化位能量的20个可能的位边界位置中选择一个位置。 可以确定该位置处的最大累加值以及距离该位置偏移5ms和15ms的偏移累加值。 然后，接收机可以确定偏移累积值中的至少一个与最大累加值的比率是否满足预定条件。 当该比率满足预定条件时，接收器可以输出该位置作为GLONASS串的位边界。

公开(公告)号：US08064507B1

公开(公告)日：2011-11-22

申请号：US12277258

申请日：2008-11-24

申请人： Hao-Ren Cheng ,  Gaspar Lee ,  Chih-Yuan Chu

发明人： Hao-Ren Cheng ,  Gaspar Lee ,  Chih-Yuan Chu

IPC分类号： H04B3/46 ,  H04B17/00 ,  H04Q1/20

CPC分类号： H04B7/01 ,  H04L25/0212 ,  H04L25/022 ,  H04L25/0232 ,  H04L25/03159

摘要： A method and apparatus in a multiple sub-carrier digital communication receiver that estimates a communication channel. A second set of channel estimates are generated based on a Wiener filter interpolation of a first set of channel estimates. Pre-determined transmit pilot symbols may be used to generate the first set of channel estimates in an OFDM communication system. The coefficients of the Wiener interpolation filter are based on a channel impulse response estimate that includes two or more narrow regions of non-zero amplitude separated by one or more wide regions of essentially zero amplitude. The Wiener interpolation filter coefficients are also based on a Doppler frequency estimate. The Doppler frequency estimate may be determined from the first set of channel estimates, while the Wiener interpolation filter coefficients may be generated from a pre-determined set of channel impulse responses.

摘要翻译： 估计通信信道的多子载波数字通信接收机中的方法和装置。 基于第一组信道估计的维纳滤波器内插生成第二组信道估计。 可以使用预定的发射导频符号来生成OFDM通信系统中的第一组信道估计。 维纳内插滤波器的系数基于信道脉冲响应估计，其包括由基本上零幅度的一个或多个宽区域分离的两个或更多个非零幅度的窄区域。 维纳内插滤波器系数也基于多普勒频率估计。 可以从第一组信道估计来确定多普勒频率估计，而可以从预定的信道脉冲响应集合生成维纳内插滤波器系数。

公开(公告)号：US08340221B1

公开(公告)日：2012-12-25

申请号：US12609294

申请日：2009-10-30

申请人： Hao-ren Cheng ,  Chih-yuan Chu ,  Justin Huang

发明人： Hao-ren Cheng ,  Chih-yuan Chu ,  Justin Huang

IPC分类号： H03K9/00

CPC分类号： H04L27/2659 ,  H04L27/2675 ,  H04L27/2695

摘要： Scattered pilots are used to estimate the integer frequency offset and OFDM symbol index simultaneously. A cross-correlation between IFFT outputs of received samples with different spectral shift and OFDM symbol index is used to identify the channel impulse response. Upon determination of the channel impulse, the estimated integer frequency offset and OFDM symbol index can then be determined.

摘要翻译： 散射导频用于同时估计整数频率偏移和OFDM符号索引。 使用具有不同频谱偏移和OFDM符号索引的接收样本的IFFT输出之间的互相关来识别信道脉冲响应。 在确定信道脉冲之后，可以确定估计的整数频率偏移和OFDM符号索引。

公开(公告)号：US20120051402A1

公开(公告)日：2012-03-01

申请号：US12870577

申请日：2010-08-27

申请人： Hao-Ren Cheng ,  Gaspar Lee ,  Qinfang Sun

发明人： Hao-Ren Cheng ,  Gaspar Lee ,  Qinfang Sun

IPC分类号： H04B1/707

CPC分类号： G01S19/243

摘要： A hybrid bit detection circuit for receiving bits from different global positioning systems, e.g. GPS and GLONASS, can include a frequency lock loop (FLL) for receiving the global positioning bits and removing Doppler frequency error and an integrate and dump (I&D) block coupled to an output of the FLL. A coherent detection circuit can be coupled to an output of the FLL and an output of the integrated and dump block. A differential detection circuit can be coupled to an output of the I&D block. Two parity check blocks can be coupled to outputs of the coherent and differential detection circuits.

摘要翻译： 一种用于从不同的全球定位系统接收比特的混合比特检测电路， GPS和GLONASS可以包括用于接收全球定位位和消除多普勒频率误差的频率锁定环（FLL），以及耦合到FLL的输出的积分和转储（I＆D）块。 相干检测电路可以耦合到FLL的输出和集成和转储块的输出。 差分检测电路可以耦合到I＆D块的输出。 两个奇偶校验块可以耦合到相干和差分检测电路的输出。

公开(公告)号：US09136937B1

公开(公告)日：2015-09-15

申请号：US12706141

申请日：2010-02-16

申请人： Hao-Ren Cheng ,  William J. McFarland

发明人： Hao-Ren Cheng ,  William J. McFarland

IPC分类号： H03K9/00 ,  H03D3/00 ,  H04B1/44 ,  H04B7/185 ,  H04B7/06 ,  H04B7/08

CPC分类号： H04B7/18545 ,  H04B7/01 ,  H04B7/0602 ,  H04B7/0802 ,  H04B7/0805 ,  H04B7/0811 ,  H04B7/1855

摘要： A system and method to provide antenna diversity by switching between antenna feeds to optimize signal quality. Antenna conditions are determined during an OFDM guard interval to minimize disruption of symbol transmission. When the signal quality assessment determines that an improved signal is available on an alternative antenna, an antenna change is performed to switch to the alternative antenna, also during a GI, again minimizing disruption in information transmission. Preferably, the process is continually applied, so that antenna conditions are monitored for changing conditions and the antenna experiencing the best signal is selected.

摘要翻译： 通过在天线馈线之间切换来提供天线分集以优化信号质量的系统和方法。 在OFDM保护间隔期间确定天线条件以最小化符号传输的中断。 当信号质量评估确定改进的信号在替代天线上可用时，执行天线改变以在GI期间切换到替代天线，同时最小化信息传输的中断。 优选地，该过程被连续地应用，使得监视天线条件以改变条件，并且选择经历最佳信号的天线。

公开(公告)号：US08451918B1

公开(公告)日：2013-05-28

申请号：US12272629

申请日：2008-11-17

申请人： Hao-Ren Cheng ,  Gaspar Lee ,  William J. McFarland ,  Paul J. Husted ,  Justin Huang

发明人： Hao-Ren Cheng ,  Gaspar Lee ,  William J. McFarland ,  Paul J. Husted ,  Justin Huang

IPC分类号： H04K1/10

CPC分类号： H04K3/228

摘要： A spur detection and spur cancellation apparatus in a multiple sub-carrier digital communication receiver includes a spur detection block that estimates, using one or more Fourier transforms, a frequency location of a narrowband interference spur in a received digital signal that includes a plurality of sub-carriers, and a spur cancellation block that attenuates the estimated narrowband interference spur. The spur detection block may use a fast Fourier transform (FFT) and/or a discrete Fourier transform (DFT) to locate a frequency and to measure a discrete power spectra of the narrowband interference spur. A channel state information block in the receiver may adjust a channel state information metric based on the located frequency and/or the measured discrete power spectra of the narrowband interference spur.

摘要翻译： 多子载波数字通信接收机中的支线检测和杂散消除装置包括一个支线检测块，其使用一个或多个傅里叶变换来估计接收到的数字信号中的窄带干扰杂波的频率位置，所述数字信号包括多个子载波 载波，以及减弱估计的窄带干扰刺激的支线消除块。 支线检测块可以使用快速傅里叶变换（FFT）和/或离散傅里叶变换（DFT）来定位频率并测量窄带干扰刺激的离散功率谱。 接收机中的信道状态信息块可以基于所定义的频率和/或窄带干扰支线的测量离散功率谱来调整信道状态信息度量。

公开(公告)号：US08149905B1

公开(公告)日：2012-04-03

申请号：US12277247

申请日：2008-11-24

申请人： Hao-Ren Cheng ,  Gaspar Lee ,  Chih-Yuan Chu

发明人： Hao-Ren Cheng ,  Gaspar Lee ,  Chih-Yuan Chu

IPC分类号： H04B3/46 ,  H04B17/00 ,  H04Q1/20

CPC分类号： H04B7/01 ,  H04B3/46 ,  H04B17/309

摘要： A method and apparatus in a multiple sub-carrier digital communication receiver estimates a Doppler frequency bandwidth. The Doppler frequency bandwidth is estimated by comparing a first set of channel estimates to a second set of channel estimates generated by Wiener filter interpolation of the first set of channel estimates. The Wiener interpolation filter coefficients are generated for various Doppler frequency bandwidths. Pre-determined transmit pilot symbols may be used to generate the first set of channel estimates in an OFDM communication system. A set of Wiener filter interpolation errors may be generated at one or more sub-carrier frequencies, for each of the different Doppler frequency bandwidths, and averaged across time and/or frequency. The Doppler frequency estimation method and apparatus may select a Doppler frequency estimate based on the set of Wiener filter interpolation errors.

摘要翻译： 多子载波数字通信接收机中的方法和装置估计多普勒频带宽度。 通过将第一组信道估计与通过第一组信道估计的维纳滤波器内插生成的第二组信道估计进行比较来估计多普勒频带。 为各种多普勒频带宽度生成维纳内插滤波器系数。 可以使用预定的发射导频符号来生成OFDM通信系统中的第一组信道估计。 对于每个不同的多普勒频率带宽，可以在一个或多个子载波频率处产生一组维纳滤波器插值误差，并且在时间和/或频率上进行平均。 多普勒频率估计方法和装置可以基于维纳滤波器插值误差的集合来选择多普勒频率估计。