公开(公告)号：US20070070963A1

公开(公告)日：2007-03-29

申请号：US11359148

申请日：2006-02-21

申请人： Linbo Li ,  Ashok Mantravadi ,  Fuyun Ling ,  Raghuraman Krishnamoorthi

发明人： Linbo Li ,  Ashok Mantravadi ,  Fuyun Ling ,  Raghuraman Krishnamoorthi

IPC分类号： H04Q7/24

CPC分类号： H04W48/16

摘要： Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel to facilitate providing seamless reception of the FLO signal, which can be superframe synchronized between RF channels. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.

摘要翻译： 描述了便于在无线通信环境中监视RF信道以确定一个或多个信道是包括仅前向链路（FLO）信号的系统和方法。 接收机可以接收具有FLO信号的第一RF信道，并且可以监视FLO信号的其他RF信道。 在确定被监视的RF信道包括FLO信号之后，接收机可以在第一RF信道和所监视的RF信道之间切换，以便于提供FLO信号的无缝接收，FLO信号可以在RF信道之间超帧同步。 可以使用广域识别信道能量检测协议和广域开销信息符号解码错误检测协议中的一个或多个来执行FLO信号检测。

公开(公告)号：US20060245349A1

公开(公告)日：2006-11-02

申请号：US11371837

申请日：2006-03-08

申请人： Bojan Vrcelj ,  Ashok Mantravadi ,  Fuyun Ling ,  Rajiv Vijayan ,  Michael Wang

发明人： Bojan Vrcelj ,  Ashok Mantravadi ,  Fuyun Ling ,  Rajiv Vijayan ,  Michael Wang

IPC分类号： H04J11/00

CPC分类号： H04L27/2662 ,  H04L5/0007 ,  H04L5/0048 ,  H04L25/0216 ,  H04L25/022 ,  H04L25/0228 ,  H04L27/261 ,  H04L27/265 ,  H04L27/2665 ,  H04L27/2679

摘要： A method for positioning a collection window for a Fourier transform function is disclosed. A first orthogonal frequency division multiplexing (OFDM) symbol and a second OFDM symbol are received. The first OFDM symbol comprises a plurality of frequency division multiplexed (FDM) symbols. The first OFDM symbol is characterized by at least two of the following: a delay spread, a first arriving path (FAP), or a last arriving path (LAP). A channel location is estimated from a channel impulse response. A point relative to the channel location is selected. A beginning of the collection window is positioned for the second OFDM symbol at the selected point. Alternatively, a point is selected at a first location relative to the channel location using a first algorithm if a delay spread is less than a predetermined length. The selected point is chosen at a second location relative to the channel location using a second algorithm if the delay spread is greater than the predetermined length.

摘要翻译： 公开了一种用于定位用于傅立叶变换函数的收集窗口的方法。 接收第一正交频分复用（OFDM）符号和第二OFDM符号。 第一OFDM符号包括多个频分复用（FDM）符号。 第一OFDM符号的特征在于以下至少两个：延迟扩展，第一到达路径（FAP）或最后到达路径（LAP）。 从信道脉冲响应估计信道位置。 选择相对于通道位置的点。 收集窗口的开始位于所选点处的第二OFDM符号。 或者，如果延迟扩展小于预定长度，则使用第一算法在相对于信道位置的第一位置处选择点。 如果延迟扩展大于预定长度，则使用第二算法在相对于信道位置的第二位置处选择所选择的点。

公开(公告)号：US20060227887A1

公开(公告)日：2006-10-12

申请号：US11248976

申请日：2005-10-11

申请人： Linbo Li ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli

发明人： Linbo Li ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli

IPC分类号： H04K1/10 ,  H04L27/06 ,  H04B1/10

CPC分类号： H04L25/0232 ,  H04L25/022

摘要： Time filtering channel estimates in a wireless communication system, such as an Orthogonal Frequency Division Multiplex (OFDM) system, can be used to improve the quality of channel estimates. The characteristics of an optimal channel estimate time filter can depend on the manner in which the channel estimate is determined as well as the time correlation of channel estimates. A receiver can implement an adaptive time filter for channel estimates in which the time filter response can vary based on channel estimate parameters. The channel estimate parameters can include the manner of determining channel estimates, a time correlation of channel estimates, and an estimated Doppler frequency. The time filter response can be varied continuously over a range of responses or can be varied discretely over a predetermined number of time filter responses.

公开(公告)号：US20060221810A1

公开(公告)日：2006-10-05

申请号：US11372394

申请日：2006-03-08

申请人： Bojan Vrcelj ,  Fuyun Ling ,  Raghuraman Krishnamoorthi ,  Vinay Murthy

发明人： Bojan Vrcelj ,  Fuyun Ling ,  Raghuraman Krishnamoorthi ,  Vinay Murthy

IPC分类号： H04J11/00 ,  H04J3/06

CPC分类号： H04L27/2656 ,  H04L27/2663 ,  H04L27/2665 ,  H04L27/2675 ,  H04L27/2695

摘要： A method for synchronizing timing of a receiver to a received orthogonal frequency division multiplexing (OFDM) signal is disclosed. A first timing acquisition is performed with a first received time division multiplexed (TDM) pilot to determine a course timing estimate of the received OFDM signal. A second timing acquisition is performed with a second TDM pilot to determine a fine timing estimate for a OFDM symbol of the received OFDM signal. In the second timing acquisition, the accumulated energy of channel taps over a detection window is determined and a trailing edge of the accumulated energy curve is detected. A Fourier transform (FT) collection window location for subsequent OFDM symbols is adjusted according to the trailing edge information.

摘要翻译： 公开了一种用于使接收机的定时与接收的正交频分复用（OFDM）信号同步的方法。 利用第一接收时分复用（TDM）导频执行第一定时获取，以确定所接收的OFDM信号的路线定时估计。 用第二TDM导频执行第二定时获取，以确定接收到的OFDM信号的OFDM符号的精确定时估计。 在第二定时获取中，确定在检测窗口上的通道抽头的累积能量，并且检测累积能量曲线的后沿。 根据后沿信息调整后续OFDM符号的傅立叶变换（FT）收集窗口位置。

公开(公告)号：US20060215778A1

公开(公告)日：2006-09-28

申请号：US11372931

申请日：2006-03-09

申请人： Vinay Murthy ,  Alok Gupta ,  Seong Taek Chung ,  Fuyun Ling

发明人： Vinay Murthy ,  Alok Gupta ,  Seong Taek Chung ,  Fuyun Ling

IPC分类号： H04K1/10

CPC分类号： G06F1/0353 ,  H04L5/0007 ,  H04L5/0048 ,  H04L27/2659 ,  H04L27/266 ,  H04L27/2662 ,  H04L27/2675 ,  H04L27/2678

摘要： Techniques for performing frequency control in an OFDM system are described. In one aspect, frequency acquisition is performed based on a received pilot, and frequency tracking is performed based on received OFDM symbols. For frequency acquisition, an initial frequency error estimate may be derived based on the received pilot, and an automatic frequency control (AFC) loop may be initialized with the initial frequency error estimate. For frequency tracking, a frequency error estimate may be derived for each received OFDM symbol, and the AFC loop may be updated with the frequency error estimate. Frequency error in input samples is corrected by the AFC loop with the initial frequency error estimate as well as the frequency error estimate for each received OFDM symbol. In another aspect, a variable number of samples of a received OFDM symbol are selected, e.g., based on the received OFDM symbol timing, for use for frequency error estimation.

摘要翻译： 描述在OFDM系统中执行频率控制的技术。 在一个方面，基于接收到的导频执行频率采集，并且基于接收的OFDM符号执行频率跟踪。 对于频率获取，可以基于接收到的导频来导出初始频率误差估计，并且可以利用初始频率误差估计来初始化自动频率控制（AFC）循环。 对于频率跟踪，可以针对每个接收的OFDM符号导出频率误差估计，并且可以用频率误差估计来更新AFC循环。 通过具有初始频率误差估计的AFC回路以及每个接收的OFDM符号的频率误差估计来校正输入采样中的频率误差。 在另一方面，例如基于所接收的OFDM符号定时，选择接收到的OFDM符号的可变数目的样本，以用于频率误差估计。

公开(公告)号：US20060203950A1

公开(公告)日：2006-09-14

申请号：US11358996

申请日：2006-02-21

申请人： Seong Chung ,  Vinay Murthy ,  Alok Gupta ,  Fuyun Ling

发明人： Seong Chung ,  Vinay Murthy ,  Alok Gupta ,  Fuyun Ling

IPC分类号： H03D3/24

CPC分类号： H03J7/04 ,  H03J1/0083

摘要： Techniques for performing frequency control using dual-loop automatic frequency control (AFC) are described. The dual-loop AFC includes an inner loop that corrects short-term frequency variations (e.g., due to Doppler effect) and an outer loop that corrects long-term frequency variations (e.g., due to component tolerances and temperature variations). In one design, a first inner loop is implemented for frequency control of a first system (e.g., a broadcast system), a second inner loop is implemented for frequency control of a second system (e.g., a cellular system), and at least one outer loop is implemented for adjusting a reference frequency used to receive signals from the first and second systems. Each inner loop estimates and corrects the frequency error in an input signal for the associated system and may be enabled when receiving the input signal from the system. The reference frequency may be used for frequency downconversion, sampling and/or other purposes.

公开(公告)号：US07106791B2

公开(公告)日：2006-09-12

申请号：US11217948

申请日：2005-08-31

申请人： Tao Chen ,  Fuyun Ling ,  Edward G. Tiedemann, Jr.

发明人： Tao Chen ,  Fuyun Ling ,  Edward G. Tiedemann, Jr.

IPC分类号： H04L1/20

CPC分类号： H04B17/327 ,  H04B17/309

摘要： In wireless communications, it is necessary to monitor the transmission quality of communications channels to maintain system performance and operation. The invention provides a way of measuring bit error rates in channels at the receiver, without diminishing channel throughput by inserting quality monitoring data into the signal at the transmitter.

公开(公告)号：US20060123310A1

公开(公告)日：2006-06-08

申请号：US11192788

申请日：2005-07-29

申请人： Michael Wang ,  Fuyun Ling ,  Murali Chari ,  Rajiv Vijayan

发明人： Michael Wang ,  Fuyun Ling ,  Murali Chari ,  Rajiv Vijayan

IPC分类号： H03M13/00 ,  H04L1/00 ,  G08C25/00 ,  G06F11/00 ,  G06F11/30

CPC分类号： H04L1/0071 ,  H01R24/38 ,  H03M13/27 ,  H03M13/271 ,  H03M13/2757 ,  H03M13/276 ,  H03M13/2771 ,  H04L1/00 ,  H04L1/0041 ,  H04L1/0066 ,  H04L1/007 ,  H04L5/0007 ,  H04L5/0042 ,  H04L5/0044 ,  H04L5/0048 ,  H04L5/0083 ,  H04L25/0226 ,  H04L27/2607 ,  H04L27/261 ,  H04L27/2626 ,  H04L27/2656 ,  H04L27/2662

摘要： A system and method for modulation diversity uses interleaving. Code bits are placed into groups and are then shuffled within each group.

公开(公告)号：US20060007989A1

公开(公告)日：2006-01-12

申请号：US11217948

申请日：2005-09-01

申请人： Tao Chen ,  Fuyun Ling ,  Edward Tiedemann

发明人： Tao Chen ,  Fuyun Ling ,  Edward Tiedemann

IPC分类号： H04B1/69 ,  H04B17/00

CPC分类号： H04B17/327 ,  H04B17/309

摘要： In wireless communications, it is necessary to monitor the transmission quality of communications channels to maintain system performance and operation. The invention provides a way of measuring bit error rates in channels at the receiver, without diminishing channel throughput by inserting quality monitoring data into the signal at the transmitter.

公开(公告)号：US06975669B2

公开(公告)日：2005-12-13

申请号：US10050338

申请日：2002-01-15

申请人： Fuyun Ling ,  Nagabhushana T. Sindhushayana ,  Eduardo A. S. Esteves

发明人： Fuyun Ling ,  Nagabhushana T. Sindhushayana ,  Eduardo A. S. Esteves

IPC分类号： H03M13/25 ,  H03M13/29 ,  H04L1/20 ,  H04B1/707

CPC分类号： H03M13/6337 ,  H03M13/2957 ,  H03M13/658 ,  H04L1/20

摘要： An efficient telecommunications receiver system for accurately decoding a received composite signal having a data signal component and a pilot signal component includes a first circuit for receiving the composite signal and extracting a pilot signal and a data signal from received composite signal. A second circuit calculates a log-likelihood ratio as a function of a channel estimate based on the pilot signal. A third circuit scales the log-likelihood ratio by a predetermined log-likelihood ratio scaling factor and provides an accurate log-likelihood value in response thereto. A fourth circuit decodes the received composite signal based on the accurate log-likelihood value and the data signal. The third circuit includes a carrier signal-to-interference ratio circuit for computing a first signal-to-interference ratio and a second signal-to-interference ratio based partly on the pilot signal.

摘要翻译： 一种用于对具有数据信号分量和导频信号分量的接收复合信号进行精确解码的有效电信接收机系统包括用于接收复合信号并从接收的复合信号中提取导频信号和数据信号的第一电路。 第二电路基于导频信号计算作为信道估计的函数的对数似然比。 第三电路将对数似然比缩小预定的对数似然比缩放因子，并响应于此提供准确的对数似然值。 第四电路基于准确的对数似然值和数据信号对接收到的复合信号进行解码。 第三电路包括用于基于导频信号计算第一信号干扰比和第二信号干扰比的载波信号干扰比电路。