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公开(公告)号：US09391813B2
公开(公告)日：2016-07-12
申请号：US12033792
申请日：2008-02-19
申请人： Rama Akella , Roger Cheng
发明人： Rama Akella , Roger Cheng
CPC分类号： H04L25/0232 , H04B3/493 , H04L25/022 , H04L27/2647 , H04L27/2665
摘要： A method and an apparatus are provided in an OFDM receiver for detecting and compensating for long echo. The method comprises a first pilot tone interpolation mechanism and a first window placement to filter a received OFDM symbol, a long echo channel detection coupled with a second pilot tone interpolation mechanism, a pre-echo and post-echo detection wherein the pre-echo condition is associated with a second new window placement, and both pre-echo and post-echo conditions place two time windows around a first peak channel response and a second peak channel response for channel estimation. The long echo is estimated by obtaining power spectra of a subset of subcarriers in one OFDM symbol, performing an inverse Fourier transform on the power spectra and determining the long echo by measuring the time between two peaks in the power profile.
摘要翻译： 在OFDM接收机中提供了一种用于检测和补偿长回波的方法和装置。 该方法包括第一导频音插值机制和第一窗口布局以过滤接收到的OFDM符号，与第二导频音插值机制耦合的长回波信道检测，前回波和后回波检测，其中预回波条件 与第二新窗口放置相关联，并且回波前和回波之间的两个条件都围绕第一峰值通道响应和第二峰值通道响应放置两个时间窗口用于信道估计。 通过在一个OFDM符号中获得子载波子集的功率谱来估计长回波，对功率谱进行傅里叶逆变换，并通过测量功率曲线中两个峰之间的时间来确定长回波。
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公开(公告)号：US07523221B2
公开(公告)日：2009-04-21
申请号：US10440494
申请日：2003-05-17
IPC分类号： G06F15/16
CPC分类号： G06F17/30569 , G06F17/30076
摘要： Described is a system and method for applying transforms to multi-part files. A request is received to access a stream within a multi-part file. Upon receipt of the request, a list of transforms associated with the stream is identified. The list is also included within the multi-part file. The transforms specified in the list of transforms are performed on data before completing the request. If the request is a write, the transforms encode the data. If the request is a read, the transforms decode the data. The list of transforms is order dependent. The list of transforms includes a data structure having a first stream that includes a map that correlates the stream with a name for the list of transforms. A second stream that lists each of the transforms for the stream. A third stream for each of the transforms listed that identifies information associated with the transform.
摘要翻译： 描述了将变换应用于多部分文件的系统和方法。 接收到访问多部分文件中的流的请求。 在接收到请求时，识别与流相关联的变换的列表。 该列表也包含在多部分文件中。 转换列表中指定的转换在完成请求之前对数据执行。 如果请求是写入，则转换对数据进行编码。 如果请求是读取，则转换解码数据。 变换列表是依赖于顺序的。 变换列表包括具有第一流的数据结构，该第一流包括将流与变换列表的名称相关联的映射。 列出流的每个变换的第二个流。 列出的每个变换的第三个流，用于标识与变换相关的信息。
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公开(公告)号：US20080198942A1
公开(公告)日：2008-08-21
申请号：US12033792
申请日：2008-02-19
申请人： Rama Akella , Roger Cheng
发明人： Rama Akella , Roger Cheng
IPC分类号： H04L27/28
CPC分类号： H04L25/0232 , H04B3/493 , H04L25/022 , H04L27/2647 , H04L27/2665
摘要： A method and an apparatus are provided in an OFDM receiver for detecting and compensating for long echo. The method comprises a first pilot tone interpolation mechanism and a first window placement to filter a received OFDM symbol, a long echo channel detection coupled with a second pilot tone interpolation mechanism, a pre-echo and post-echo detection wherein the pre-echo condition is associated with a second new window placement, and both pre-echo and post-echo conditions place two time windows around a first peak channel response and a second peak channel response for channel estimation. The long echo is estimated by obtaining power spectra of a subset of subcarriers in one OFDM symbol, performing an inverse Fourier transform on the power spectra and determining the long echo by measuring the time between two peaks in the power profile.
摘要翻译： 在OFDM接收机中提供了一种用于检测和补偿长回波的方法和装置。 该方法包括第一导频音插值机制和第一窗口布局以过滤接收到的OFDM符号，与第二导频音插值机制耦合的长回波信道检测，前回波和后回波检测，其中预回波条件 与第二新窗口放置相关联，并且回波前和回波之间的两个条件都围绕第一峰值通道响应和第二峰值通道响应放置两个时间窗口用于信道估计。 通过在一个OFDM符号中获得子载波子集的功率谱来估计长回波，对功率谱进行傅里叶逆变换，并通过测量功率曲线中两个峰之间的时间来确定长回波。
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公开(公告)号：US06571393B1
公开(公告)日：2003-05-27
申请号：US09084501
申请日：1998-05-27
申请人： Tsz-Mei Ko , Ming Liou , Kwan-Fai Cheung , Roger Cheng , Bo Hu , Donghui Qu
发明人： Tsz-Mei Ko , Ming Liou , Kwan-Fai Cheung , Roger Cheng , Bo Hu , Donghui Qu
IPC分类号： H03G1104
摘要： A data transmission system is proposed, for example for video-on-demand, internet or multimedia applications, in which a number of subscribers in a building are connected to a central server through at least in part twisted pair cables within the building. Compensation for the channel distortion caused by the use of twisted pair cables is provided by the use of pre-emphasis filters in the outgoing data lines from the server. The required coefficients for the pre-emphasis filters are established by first characterizing the distortion properties of a channel by the use of a test signal.
摘要翻译： 提出了一种数据传输系统，例如用于视频点播，互联网或多媒体应用，其中建筑物中的许多用户通过至少部分地在建筑物内的双绞线电缆连接到中央服务器。 通过在服务器的输出数据线中使用预加重滤波器来提供使用双绞线电缆造成的信道失真的补偿。 通过首先通过使用测试信号来表征信道的失真特性来建立用于预加重滤波器的所需系数。
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公开(公告)号：US20080144730A1
公开(公告)日：2008-06-19
申请号：US11935316
申请日：2007-11-05
申请人： Ramakrishna Akella , Roger Cheng
发明人： Ramakrishna Akella , Roger Cheng
IPC分类号： H04L27/28
CPC分类号： H04L25/0234 , H04L25/0204 , H04L25/022 , H04L27/2647
摘要： A method for performing channel estimation of an OFDM channel includes, in part, interpolating pilots for sub-channels positioned within a first range of an OFDM symbol, and estimating frequency response of sub-channels positioned within a second range of the OFDM symbol. The first range is defined by subchannels positioned substantially away from channel edges and the second range is defined by subchannels positioned substantially near channel edges. The method optionally includes transforming the pilots from frequency domain into the time-domain, time-domain windowing to obtain a channel impulse response having a multitude of discrete values, estimating the discrete values within the channel impulse response; and transforming the channel impulse response to the frequency domain.
摘要翻译： 用于执行OFDM信道的信道估计的方法部分地包括针对位于OFDM符号的第一范围内的子信道内插导频，以及估计位于OFDM符号的第二范围内的子信道的频率响应。 第一范围由基本上远离通道边缘定位的子通道限定，第二范围由基本上位于通道边缘附近的子通道定义。 该方法可选地包括将导频从频域变换为时域，时域窗口，以获得具有多个离散值的信道脉冲响应，估计信道脉冲响应内的离散值; 并将信道脉冲响应变换到频域。
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公开(公告)号：US20080112494A1
公开(公告)日：2008-05-15
申请号：US11870726
申请日：2007-10-11
申请人： Rama Akella , Roger Cheng
发明人： Rama Akella , Roger Cheng
CPC分类号： H04L25/0204 , H04L5/023 , H04L25/0232 , H04L27/261
摘要： An efficient channel estimation system and method provides good performance under high Doppler conditions and is suitable for OFDM systems such as DVB-T. A number of different pilot interpolations techniques enable the estimation of channel for the OFDM systems. For 2k and 4k modes, the channel is estimated using the preceding symbol, the present symbol, and two succeeding symbols. For an 8k mode, only one future symbol is used to estimate the channel.
摘要翻译： 高效的信道估计系统和方法在高多普勒条件下提供良好的性能，适用于DVB-T等OFDM系统。 许多不同的导频插值技术使得能够估计OFDM系统的信道。 对于2k和4k模式，使用前面的符号，当前符号和两个后续符号来估计信道。 对于8k模式，仅使用一个未来符号来估计频道。
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公开(公告)号：US20060245473A1
公开(公告)日：2006-11-02
申请号：US11118227
申请日：2005-04-28
申请人： Roger Cheng , Navneet Dour , Scott Miller , David Freker , Harishankar Sridharan , Mahmood Alam
发明人： Roger Cheng , Navneet Dour , Scott Miller , David Freker , Harishankar Sridharan , Mahmood Alam
IPC分类号： H04B1/00
CPC分类号： G06F13/423 , Y02D10/14 , Y02D10/151
摘要： An embodiment of the present invention is a technique to integrate data for a source synchronous protocol. A delay generator generates at least an integrating strobe from a data strobe synchronizing a data having a data window using the source synchronous protocol. A pulse generator generates a pulse from the at least integrating strobe. An integrating receiver integrates the data over an integration window defined by the pulse. The integration window is within the data window.
摘要翻译： 本发明的一个实施例是用于集成源同步协议的数据的技术。 延迟发生器使用源同步协议从数据选通器产生至少一个使具有数据窗口的数据同步的积分选通脉冲。 脉冲发生器从至少积分选通脉冲产生脉冲。 积分接收器通过由脉冲定义的积分窗口来集成数据。 集成窗口在数据窗口内。
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公开(公告)号：US20060119381A1
公开(公告)日：2006-06-08
申请号：US11337131
申请日：2006-01-19
申请人： Navneet Dour , Roger Cheng
发明人： Navneet Dour , Roger Cheng
IPC分类号： H03K19/003
CPC分类号： H03K19/018521 , H03K19/00384 , H03K19/018585
摘要： Embodiments include an on die termination circuit. The on die termination circuit may be programmable. The on die termination circuit may be programmed to compensate for environmental conditions and the physical characteristics of the device. The programmed on die termination circuit allows for faster transfer rates over communication lines by reducing the time needed to recover from signal reflection and similar issues.
摘要翻译： 实施例包括芯片上终端电路。 芯片终端电路可以是可编程的。 芯片终端电路可以被编程以补偿环境条件和设备的物理特性。 通过减少从信号反射恢复所需的时间和类似的问题，编程的芯片终端电路允许通信线路上的传输速率更快。
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公开(公告)号：US08027395B2
公开(公告)日：2011-09-27
申请号：US11935316
申请日：2007-11-05
申请人： Ramakrishna Akella , Roger Cheng
发明人： Ramakrishna Akella , Roger Cheng
IPC分类号： H04L27/28
CPC分类号： H04L25/0234 , H04L25/0204 , H04L25/022 , H04L27/2647
摘要： A method for performing channel estimation of an OFDM channel includes, in part, interpolating pilots for sub-channels positioned within a first range of an OFDM symbol, and estimating frequency response of sub-channels positioned within a second range of the OFDM symbol. The first range is defined by subchannels positioned substantially away from channel edges and the second range is defined by subchannels positioned substantially near channel edges. The method optionally includes transforming the pilots from frequency domain into the time-domain, time-domain windowing to obtain a channel impulse response having a multitude of discrete values, estimating the discrete values within the channel impulse response; and transforming the channel impulse response to the frequency domain.
摘要翻译： 用于执行OFDM信道的信道估计的方法部分地包括针对位于OFDM符号的第一范围内的子信道内插导频，以及估计位于OFDM符号的第二范围内的子信道的频率响应。 第一范围由基本上远离通道边缘定位的子通道限定，第二范围由基本上位于通道边缘附近的子通道定义。 该方法可选地包括将导频从频域变换为时域，时域窗口，以获得具有多个离散值的信道脉冲响应，估计信道脉冲响应内的离散值; 并将信道脉冲响应变换到频域。
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公开(公告)号：US20060245519A1
公开(公告)日：2006-11-02
申请号：US11118228
申请日：2005-04-28
申请人： Roger Cheng , Harishankar Sridharan , Navneet Dour , Hing To
发明人： Roger Cheng , Harishankar Sridharan , Navneet Dour , Hing To
IPC分类号： H04L27/00
CPC分类号： H04L25/20
摘要： An embodiment of the present invention is a technique to calibrate an integrating receiver. A delay calibration circuit calibrates an adjusting code of a chain of delay elements and positioning of at least an integrating strobe used to define an integration window for the integrating receiver. An integrating receiver calibration pulse generator generates an IR calibration pulse from the at least integrating strobe. A calibration controller controls calibrating the adjusting code and the positioning of the at least integrating strobe.
摘要翻译： 本发明的实施例是校准积分接收器的技术。 延迟校准电路校准延迟元件链的调整代码，并且至少定位用于为积分接收器定义积分窗口的积分选通脉冲。 积分接收器校准脉冲发生器从至少积分选通器产生IR校准脉冲。 校准控制器控制校准调整代码和至少积分选通脉冲的定位。
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