公开(公告)号：US20070070971A1

公开(公告)日：2007-03-29

申请号：US11495480

申请日：2006-07-27

Applicant: Fuyun Ling ,  Murali Chari ,  Rajiv Vijayan ,  Ashok Mantravadi ,  Alok Gupta ,  Krishna Mukkavilli ,  Michael Wang ,  Bojan Vrcelj ,  Bruce Collins

Inventor： Fuyun Ling ,  Murali Chari ,  Rajiv Vijayan ,  Ashok Mantravadi ,  Alok Gupta ,  Krishna Mukkavilli ,  Michael Wang ,  Bojan Vrcelj ,  Bruce Collins

IPC: H04J3/24 ,  H04L12/56

CPC classification number: H04L1/0002 ,  H04L1/0017 ,  H04L1/0041 ,  H04L1/0075 ,  H04L5/0007 ,  H04L5/0048 ,  H04L27/2613 ,  H04L27/2647 ,  H04L27/2662 ,  H04L69/32 ,  H04W48/08 ,  H04W72/005 ,  H04W80/00 ,  H04W88/02 ,  H04W92/10

Abstract: Systems and methods are provided for processing forward link only (FLO) signals. A device receives a FLO signal, processes a TDM pilot comprising a TDM Pilot 1, a TDM Pilot 2, a WIC, a LIC, a Transition Pilot Channel, and a Positioning Pilot, from the FLO signal, processes an overhead information symbol (OIS) comprising a wide-area OIS and a local-area OIS, from the FLO signal, processes an FDM pilot comprising a wide-area FDM pilot and a local-area FDM pilot, from the FLO signal; and processes data comprising wide-area data and local-area data, from the FLO signal.

Abstract translation: 提供系统和方法用于仅处理前向链路（FLO）信号。 设备接收FLO信号，从FLO信号处理包括TDM导频1，TDM导频2，WIC，LIC，转换导频信道和定位导频的TDM导频，处理开销信息符号（OIS ）包括来自FLO信号的广域OIS和局域OIS，从FLO信号处理包括广域FDM导频和本地FDM导频的FDM导频; 并从FLO信号处理包括广域数据和局域数据的数据。

公开(公告)号：US20060111148A1

公开(公告)日：2006-05-25

申请号：US10533248

申请日：2003-10-29

Applicant: Krishna Mukkavilli ,  Ashutosh Sabharwal ,  Behnaam Aazhang

Inventor： Krishna Mukkavilli ,  Ashutosh Sabharwal ,  Behnaam Aazhang

IPC: H04B7/00

CPC classification number: H04B7/0639 ,  H01Q21/00 ,  H04B7/0443 ,  H04B7/0617 ,  H04B7/0669 ,  H04W52/42

Abstract: Beamforming systems having a few bits of channel state information fed back to the transmitter benefit from low complexity decoding structures and performances gains compared with systems that do not have channel state feedback. Both unit rank and higher rank systems are implemented. Substantial design effort may be avoided by following a method of using functions formulated for space-time systems with the change that the channel coherence time is equated to the number of transmit antennas and the number of antennas in the space-time formulation is fixed at one.

Abstract translation: 具有反馈到发射机的几比特信道状态信息的波束成形系统与没有信道状态反馈的系统相比，受益于低复杂性解码结构和性能增益。 实现了单位级和高级制。 通过遵循使用为空时系统制定的功能的方法可以避免大量的设计努力，其中信道相干时间等于发射天线的数量，并且时空公式中的天线数量固定在一个 。

公开(公告)号：US20070179782A1

公开(公告)日：2007-08-02

申请号：US11557921

申请日：2006-11-08

Applicant: Seong Chung ,  Krishna Mukkavilli ,  Vinay Murthy ,  Tao Tian

Inventor： Seong Chung ,  Krishna Mukkavilli ,  Vinay Murthy ,  Tao Tian

IPC: G10L19/14

CPC classification number: H04L27/2657 ,  H04L27/2675

Abstract: Methods and apparatus for frequency tracking of a received signal. In an aspect, a method is provided wherein the received signal comprises one or more symbols having a periodic structure. The method comprises receiving a plurality of samples of a selected symbol that comprises pilot signals scrambled with data and determining a window size and a periodicity factor. The method also comprises accumulating a correlation between samples in a first window and samples in a second window to produce an accumulated correlation value, wherein the first and second windows have a size and a separation based on the window size and the periodicity factor, respectively, and deriving a frequency error estimate based on the accumulated correlation value.

Abstract translation: 接收信号频率跟踪的方法和装置。 在一方面，提供了一种方法，其中接收的信号包括具有周期性结构的一个或多个符号。 该方法包括：接收包含由数据加扰的导频信号和确定窗口大小和周期因子的所选符号的多个样本。 该方法还包括在第一窗口中累积样本之间的相关性并在第二窗口中采样以产生累加的相关值，其中第一和第二窗口分别具有基于窗口大小和周期性因子的大小和间隔， 以及基于所累积的相关值导出频率误差估计。

公开(公告)号：US20070140385A1

公开(公告)日：2007-06-21

申请号：US11303487

申请日：2005-12-15

Applicant: Krishna Mukkavilli ,  Michael Wang ,  Raghuraman Krishnamoorthi

Inventor： Krishna Mukkavilli ,  Michael Wang ,  Raghuraman Krishnamoorthi

IPC: H04L27/06

CPC classification number: H04L27/2662 ,  H04L25/0202 ,  H04L27/2686

Abstract: Apparatus and methods for use in a wireless communication system are disclosed for determining a timing position for channel activity in order to resolve timing ambiguity. A disclosed apparatus includes a processor that determines when channel activity occurs in at least one of an early or a late arrival position in a communication channel estimate and unwraps the channel activity in either the early arrival position or the late arrival position to a corresponding late or early arrival unwrapped channel activity position in the wireless channel estimate. The processor correlates symbol data in the communication signal corresponding to both the channel activity and the unwrapped channel activity to symbol data of the main channel activity. The processor determines whether a correct timing position of the channel activity is one of the early or late arrival positions based on the correlations, thus resolving timing ambiguity. Complementary methods are also disclosed.

Abstract translation: 公开了用于无线通信系统中的装置和方法，用于确定信道活动的定时位置，以便解决定时模糊。 所公开的装置包括处理器，其确定在通信信道估计中的早期或迟到到达位置中的至少一个中何时发生信道活动，并且将早期到达位置或延迟到达位置中的信道活动解包到相应的延迟或 在无线信道估计中提前到达解开的频道活动位置。 处理器将对应于信道活动和解开的信道活动的通信信号中的符号数据与主信道活动的符号数据相关联。 处理器基于相关性确定信道活动的正确定时位置是早期还是迟到位置之一，从而解决定时模糊度。 还公开了互补方法。

公开(公告)号：US20060203710A1

公开(公告)日：2006-09-14

申请号：US11366779

申请日：2006-03-01

Applicant: Krishna Mukkavilli ,  Kevin Cousineau ,  Seong Chung

Inventor： Krishna Mukkavilli ,  Kevin Cousineau ,  Seong Chung

IPC: H04J11/00

CPC classification number: H04L25/0232 ,  H04L25/0212 ,  H04L25/0216 ,  H04L25/022 ,  H04L25/025 ,  H04L27/2647

Abstract: Channel estimation in a spectrally shaped wireless communication system in which an initial frequency response estimate is obtained for a first set of P uniformly spaced subbands (1) based on pilot symbols received on a second set of subbands used for pilot transmission and (2) using extrapolation and/or interpolation. A channel impulse response estimate is obtained by performing an IFFT on a frequency response estimate. The number of taps in the channel impulse response can be truncated to a predetermined number of taps determined based on an operating mode of the second set of P uniformly spaced subbands. The energy of each tap value remaining after truncation can be compared to a predetermined threshold and modified based on the results of the comparison. The predetermined threshold can be determined based on an operating mode. A final frequency response estimate for each mode within each OFDM symbol is derived.

Abstract translation: 在频谱形状的无线通信系统中的信道估计，其中基于在用于导频传输的第二组子带上接收的导频符号获得针对第一组P均匀间隔子带（1）的初始频率响应估计，以及（2）使用 外插和/或插值。 通过对频率响应估计执行IFFT来获得信道脉冲响应估计。 可以将信道脉冲响应中的抽头数量截断为基于第二组P均匀间隔子带的操作模式确定的预定数量的抽头。 截断后剩余的每个抽头值的能量可以与预定阈值进行比较，并根据比较结果进行修改。 可以基于操作模式来确定预定阈值。 导出每个OFDM符号内每个模式的最终频率响应估计。

公开(公告)号：US20050163258A1

公开(公告)日：2005-07-28

申请号：US11022513

申请日：2004-12-22

Applicant: Dhananjay Gore ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli ,  Raghuraman Krishnamoorthi

Inventor： Dhananjay Gore ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli ,  Raghuraman Krishnamoorthi

IPC: H04L25/02 ,  H04L27/26 ,  H04B1/10

CPC classification number: H04L25/0224 ,  H04L25/0212 ,  H04L25/022

Abstract: 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.

Abstract translation: 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：US08443255B2

公开(公告)日：2013-05-14

申请号：US12869555

申请日：2010-08-26

Applicant: Jing Jiang ,  Tao Tian ,  Raghuraman Krishnamoorthi ,  Xinmiao Zhang ,  Ashok Mantravadi ,  Krishna Mukkavilli

Inventor： Jing Jiang ,  Tao Tian ,  Raghuraman Krishnamoorthi ,  Xinmiao Zhang ,  Ashok Mantravadi ,  Krishna Mukkavilli

IPC: H03M13/00

CPC classification number: H03M13/1111 ,  H03M13/1191 ,  H03M13/1515 ,  H03M13/2966 ,  H03M13/616 ,  H04L1/005 ,  H04L1/0057

Abstract: A method of generating a parity check matrix for iterative decoding of a linear block code includes: determining a set of parity check vectors for the linear block code; ordering according to Hamming weight non-zero parity check vectors of the set; selecting a criterion for generating the parity check matrix; and building the parity check matrix by incrementally selecting according to the criterion a parity check vector for each consecutive row of the parity check matrix, wherein the parity check vector is selected from the ordered non-zero parity check vectors remaining in the set.

Abstract translation: 一种生成用于线性块码的迭代解码的奇偶校验矩阵的方法包括：确定用于线性块码的一组奇偶校验向量; 根据汉明重量非零奇偶校验向量进行排序; 选择用于生成奇偶校验矩阵的标准; 以及通过根据所述标准逐渐选择所述奇偶校验矩阵的每个连续行的奇偶校验向量来构建所述奇偶校验矩阵，其中所述奇偶校验向量是从所述组中剩余的有序非零奇偶校验向量中选择的。

公开(公告)号：US20080107192A1

公开(公告)日：2008-05-08

申请号：US11834671

申请日：2007-08-06

Applicant: Krishna Mukkavilli ,  Raghuraman Krishnamoorthi ,  Rajiv Vijayan

Inventor： Krishna Mukkavilli ,  Raghuraman Krishnamoorthi ,  Rajiv Vijayan

IPC: H04L27/28

CPC classification number: H04L5/0048 ,  H04L5/0007 ,  H04L5/0044 ,  H04L25/0224

Abstract: A transmitter or receiver device includes a processing system configured to have one or more pilot interlace vectors and one or more distance vectors. The processing system is further configured to generate a first slot interlace for a first slot based on the one or more pilot interlace vectors, and is further configured to generate a second slot interlace for a second slot based on the first slot interlace and the one or more distance vectors. Additional slot interlaces for all other slots may also be generated based on the first slot interlace and the one or more distance vectors.

Abstract translation: 发射机或接收机设备包括被配置为具有一个或多个导频交织向量和一个或多个距离向量的处理系统。 所述处理系统还被配置为基于所述一个或多个导频交错向量来生成用于第一时隙的第一时隙交织，并且还被配置为基于所述第一时隙交织和所述第一时隙交织而生成用于第二时隙的第二时隙交织， 更多距离矢量。 也可以基于第一时隙交错和一个或多个距离矢量来生成用于所有其他时隙的附加时隙交织。

公开(公告)号：US20060227887A1

公开(公告)日：2006-10-12

申请号：US11248976

申请日：2005-10-11

Applicant: Linbo Li ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli

Inventor： Linbo Li ,  Ashok Mantravadi ,  Fuyun Ling ,  Krishna Mukkavilli

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

CPC classification number: H04L25/0232 ,  H04L25/022

Abstract: 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.