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：US08553822B2

公开(公告)日：2013-10-08

申请号：US11022513

申请日：2004-12-22

申请人： Dhananjay Ashok Gore ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Kiran Mukkavilli ,  Raghuraman Krishnamoorthi

发明人： Dhananjay Ashok Gore ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Kiran Mukkavilli ,  Raghuraman Krishnamoorthi

IPC分类号： H04B1/10

CPC分类号： H04L25/0224 ,  H04L25/0212 ,  H04L25/022

摘要： Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, time filtering is utilized. Time filtering is utilized to combat excess delay spread effects in channel estimation. The time filtering is performed in the presence of staggered pilots and helps in improving the channel estimate in the presence of excess delay spread.

摘要翻译： 描述了具有超延迟扩展的OFDM系统的导频传输和信道估计技术。 为了减轻多余延迟扩展的有害影响，利用时间滤波。 利用时间滤波来对付信道估计中的多余延迟扩散效应。 在存在交错导频的情况下执行时间滤波，并有助于在存在超延迟扩展的情况下改善信道估计。

公开(公告)号：US08355354B2

公开(公告)日：2013-01-15

申请号：US12646520

申请日：2009-12-23

申请人： Rajiv Vijayan ,  Fuyun Ling ,  Gordon K. Walker ,  Murali R. Chari ,  Ashok Mantravadi ,  Anand D. Subramaniam

发明人： Rajiv Vijayan ,  Fuyun Ling ,  Gordon K. Walker ,  Murali R. Chari ,  Ashok Mantravadi ,  Anand D. Subramaniam

IPC分类号： H04H20/71

CPC分类号： H04L5/0041 ,  H04L5/0007 ,  H04L5/0044 ,  H04L5/0048 ,  H04L12/189 ,  H04W72/005

摘要： To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

摘要翻译： 为了在无线广播网络中广播具有不同层次的不同类型的传输，每个基站根据第一模式（或编码和调制方案）处理广域传输的数据，以产生广域的数据符号 根据第二模式传输和处理用于本地传输的数据，以产生用于本地传输的数据符号。 分别基于广域和本地传输的期望覆盖来选择第一和第二模式。 基站还为本地和广域传输生成导频和开销信息。 用于本地和广域传输的数据，导频和开销信息被复用到它们的传输跨度，其可以是不同组的频率子带，不同时间段或不同时间段中的不同子带组。 多于两种不同类型的传输也可以被复用和广播。

公开(公告)号：US08311133B2

公开(公告)日：2012-11-13

申请号：US11834653

申请日：2007-08-06

申请人： Durk L. van Veen ,  Ashok Mantravadi ,  Raghuraman Krishnamoorthi ,  Murali Ramaswamy Chari ,  Krishna Kiran Mukkavilli ,  Fuyun Ling

发明人： Durk L. van Veen ,  Ashok Mantravadi ,  Raghuraman Krishnamoorthi ,  Murali Ramaswamy Chari ,  Krishna Kiran Mukkavilli ,  Fuyun Ling

IPC分类号： H04L27/28 ,  H04B7/216

CPC分类号： H04L27/2613 ,  H04L5/0007 ,  H04L5/0044 ,  H04L5/0048 ,  H04L5/0053 ,  H04L5/008 ,  H04L5/0094 ,  H04L27/2607 ,  H04L27/2626 ,  H04L27/2628 ,  H04L27/2647 ,  H04L27/2656

摘要： A new channel is added to FLO networks that carries embedded signaling parameter information. The design is such that regardless of the actual values of the signaling parameters conveyed, a receiver will be able to demodulate this new channel. Moreover, the addition of the new channel does not render a FLO network that has been so configured to not be backwards-compatible with existing devices.

摘要翻译： 一个新的信道被添加到携带嵌入式信令参数信息的FLO网络中。 这种设计使得无论传达的信令参数的实际值如何，接收机将能够解调这个新的信道。 此外，添加新频道并不会使FLO网络被配置为不与现有设备向后兼容。

公开(公告)号：US08229708B2

公开(公告)日：2012-07-24

申请号：US11563627

申请日：2006-11-27

申请人： Ashok Mantravadi ,  Fuyun Ling ,  Krishna Kiran Mukkavilli ,  Raghuraman Krishnamoorthi

发明人： Ashok Mantravadi ,  Fuyun Ling ,  Krishna Kiran Mukkavilli ,  Raghuraman Krishnamoorthi

IPC分类号： G01R15/00 ,  G01R21/00 ,  H04B15/00 ,  H04B1/10 ,  H04B3/46 ,  H04B1/00 ,  H04B17/00 ,  H04B1/04 ,  H04B1/12 ,  H04L25/08

CPC分类号： H04B1/1027

摘要： Methods and apparatus for signal and interference energy estimation in a communication system. In an aspect, a method includes setting a threshold value, and comparing a channel estimate to the threshold value to determine an interference estimate (Iest). The method also includes averaging the interference estimate (Iest) to determine average channel interference (Ic), and determining interference energy (I) based on the interference estimate (Iest) and the average channel interference (Ic). In another aspect, an apparatus includes threshold logic configured to set a threshold value and compare a channel estimate to the threshold value to determine an interference estimate (Iest). The apparatus includes averaging logic configured to average the interference estimate (Iest) to determine average channel interference (Ic), and summing logic configured to determine interference energy (I) based on the interference estimate (Iest) and average channel interference (Ic).

摘要翻译： 通信系统中信号和干扰能量估计的方法和装置。 一方面，一种方法包括设置阈值，以及将信道估计与阈值进行比较以确定干扰估计（Iest）。 该方法还包括对干扰估计（Iest）进行平均以确定平均信道干扰（Ic），以及基于干扰估计（Iest）和平均信道干扰（Ic）来确定干扰能量（I）。 在另一方面，一种装置包括阈值逻辑，其被配置为设置阈值并将信道估计与阈值进行比较以确定干扰估计（Iest）。 该装置包括被配置为平均干扰估计（Iest）以确定平均信道干扰（Ic）的平均逻辑，以及被配置为基于干扰估计（Iest）和平均信道干扰（Ic））来确定干扰能量（I）的求和逻辑。

公开(公告)号：US08175123B2

公开(公告)日：2012-05-08

申请号：US11371837

申请日：2006-03-08

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

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

IPC分类号： H04J3/08

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：US07660275B2

公开(公告)日：2010-02-09

申请号：US10968787

申请日：2004-10-18

申请人： Rajiv Vijayan ,  Fuyun Ling ,  Gordon Kent Walker ,  Ramaswamy Murali ,  Ashok Mantravadi ,  Anand Subramaniam ,  Krishnamurthy Viswanathan, legal representative

发明人： Rajiv Vijayan ,  Fuyun Ling ,  Gordon Kent Walker ,  Ramaswamy Murali ,  Ashok Mantravadi ,  Anand Subramaniam

IPC分类号： H04H20/71

CPC分类号： H04L5/0041 ,  H04L5/0007 ,  H04L5/0044 ,  H04L5/0048 ,  H04L12/189 ,  H04W72/005

摘要： To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

摘要翻译： 为了在无线广播网络中广播具有不同层次的不同类型的传输，每个基站根据第一模式（或编码和调制方案）处理广域传输的数据，以产生广域的数据符号 根据第二模式传输和处理用于本地传输的数据，以产生用于本地传输的数据符号。 分别基于广域和本地传输的期望覆盖来选择第一和第二模式。 基站还为本地和广域传输生成导频和开销信息。 用于本地和广域传输的数据，导频和开销信息被复用到它们的传输跨度，其可以是不同组的频率子带，不同时间段或不同时间段中的不同子带组。 多于两种不同类型的传输也可以被复用和广播。

公开(公告)号：US20060233097A1

公开(公告)日：2006-10-19

申请号：US11371536

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 characterizing a communication channel is disclosed. A detection window is moved through a channel profile to accumulate tap energies in the channel profile within the detection window into an accumulated energy curve. A peak at a maximum in the accumulated energy curve is determined. A band relative to the accumulated energy curve is defined. A first arriving path (FAP) is determined using a trailing edge found near a second end of a zone in the accumulated energy curve. A leading edge is found near a first end of the zone of the accumulated energy curve. The last arriving path (LAP) is determined using the leading edge. The band defines a zone of the accumulated energy curve at or near the maximum that is within the band.

摘要翻译： 公开了一种用于表征通信信道的方法。 检测窗口通过通道轮廓移动，以将检测窗口内的通道轮廓中的抽头能量累积为累积的能量曲线。 确定累积能量曲线中最大值的峰值。 定义相对于累积能量曲线的带。 使用在累积能量曲线中的区域的第二端附近发现的后沿来确定第一到达路径（FAP）。 在累积能量曲线的区域的第一端附近发现前沿。 最后到达路径（LAP）使用前沿确定。 频带定义在频带内或附近的最大值处的累积能量曲线的区域。

公开(公告)号：US20060227812A1

公开(公告)日：2006-10-12

申请号：US11373764

申请日：2006-03-09

申请人： Bojan Vrcelj ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli

发明人： Bojan Vrcelj ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli

IPC分类号： H04J3/06

CPC分类号： H04L25/0232 ,  H04L25/0212 ,  H04L25/0224 ,  H04L25/025 ,  H04L27/2662 ,  H04L27/2665

摘要： Systems and methods are provided for determining and applying timing corrections in a digital communications system. In an aspect, a timing correction method is provided for a multi-carrier system. This includes aligning two or more symbols with respect to each other from a symbol subset in order to account for timing differences between the symbols. The symbol alignment is first carried out to generate channel estimates for data demodulation. The channel estimates, thus generated, along with the timing alignment information are in turn used for determining timing corrections to be applied to future symbols.

摘要翻译： 提供了用于在数字通信系统中确定和应用定时校正的系统和方法。 在一方面，为多载波系统提供定时校正方法。 这包括从符号子集彼此对准两个或更多个符号，以便考虑符号之间的时序差异。 首先执行符号对齐以产生用于数据解调的信道估计。 由此生成的信道估计与定时对准信息一起被用于确定要应用于未来符号的定时校正。

公开(公告)号：US20060215539A1

公开(公告)日：2006-09-28

申请号：US11371535

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 ,  H04Q7/00 ,  H04Q7/20

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 determining a communication channel location is disclosed. A first subset of a plurality of channel impulse responses is averaged over a first time period to produce a first filtered channel impulse response, and a second subset of the plurality of channel impulse responses is averaged over a second time period to produce a second filtered channel impulse response. The second time period is different from the first time period, and the second subset is different from the first subset. The communication channel location is determined using the first filtered channel impulse response and the second filtered channel impulse response.

摘要翻译： 公开了一种用于确定通信信道位置的方法。 多个信道脉冲响应的第一子集在第一时间段内被平均以产生第一经滤波的信道脉冲响应，并且在第二时间周期上平均多个信道脉冲响应的第二子集，以产生第二滤波信道 脉冲响应。 第二时间段与第一时间段不同，第二子集与第一子集不同。 使用第一滤波信道脉冲响应和第二滤波信道脉冲响应来确定通信信道位置。