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71. 发明申请

US20090016380A1 Methods and Apparatus for RF Channel Switching in a Multi-Frequency Network 失效
标题翻译：用于多频网络中RF信道切换的方法和装置
公开(公告)号：US20090016380A1
公开(公告)日：2009-01-15
申请号：US12051209
申请日：2008-03-19
申请人： Binita Gupta , An Mei Chen , Devarshi Shah , Linbo Li , Raghuraman Krishnamoorthi , Ashok Mantravadi , Taoufik Tani
发明人： Binita Gupta , An Mei Chen , Devarshi Shah , Linbo Li , Raghuraman Krishnamoorthi , Ashok Mantravadi , Taoufik Tani
IPC分类号： H04J1/00
CPC分类号： H04W76/11 , H04W48/12 , H04W72/02 , H04W76/15
摘要： Methods and apparatus for RF channel switching in a multi-frequency network. In an aspect, a method includes identifying a multiplex set that comprises one or more content flows, wherein the multiplex set is one of a vertical multiplex (VM) set and a unified multiplex (UM) set, generating an overhead message that associates one or more RF carrier frequencies with the one or more content flows, and transmitting the overhead message over the multi-frequency network. An apparatus includes input logic configured to receive an overhead message that associates one or more content flows with one or more RF carrier frequencies, and processing logic configured to detect a channel switch event that identifies a selected content flow, determine a selected RF carrier frequency associated with the selected content flow based on the overhead message, and switch to the selected RF carrier frequency to receive the selected content flow.
摘要翻译：多频网络中RF信道切换的方法和装置。一方面，一种方法包括识别包括一个或多个内容流的多路复用集合，其中多路复用集合是垂直多路复用（VM）集合和统一多路复用（UM）集合之一，生成将开销消息与一个或多个内容流相关联的开销消息，具有一个或多个内容流的更多RF载波频率，以及通过多频网络发送开销消息。一种装置包括输入逻辑，其被配置为接收将一个或多个内容流与一个或多个RF载波频率相关联的开销消息，以及被配置为检测识别所选内容流的信道切换事件的处理逻辑，确定所选择的RF载波频率相关联所选择的内容流程基于开销消息，并且切换到所选择的RF载波频率以接收所选择的内容流。

72. 发明申请

US20070230596A1 Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal 有权
标题翻译：降低OFDM发射信号的峰均比的方法和装置
公开(公告)号：US20070230596A1
公开(公告)日：2007-10-04
申请号：US11519256
申请日：2006-09-11
申请人： Durk L. van Veen , Fuyun Ling , Raghuraman Krishnamoorthi
发明人： Durk L. van Veen , Fuyun Ling , Raghuraman Krishnamoorthi
IPC分类号： H04K1/10
CPC分类号： H04L27/2614 , H04L27/2615
摘要： Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal. In an aspect, a method is provided for reducing a peak to average ratio of a transmit waveform. The method includes obtaining a primary scrambler sequence, generating a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining the primary and secondary scrambler sequences to produce a PAR reduction sequence. In another aspect, an apparatus is provided for reducing a peak to average ratio of a transmit waveform. The apparatus includes a secondary generator configured to generate a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining logic configured to combine a primary scrambler sequence and the secondary scrambler sequences to produce a PAR reduction sequence.
摘要翻译：降低OFDM发射信号的峰均比的方法和装置。在一方面，提供了一种降低发射波形的峰均比的方法。该方法包括：获得主加扰器序列，产生具有基于要加扰的数据的长度特性的次扰频序列，以及组合所述主加扰序列和次加扰序列以产生PAR减少序列。在另一方面，提供一种用于减小发射波形的峰均比的装置。该装置包括辅助发生器，其被配置为产生具有基于要加扰的数据的长度特性的二次扰频器序列，以及被配置为组合主加扰器序列和次加扰器序列以产生PAR减少序列的组合逻辑。

73. 发明申请

US20070217525A1 Frequency tracking which adapts to timing synchronization 有权
标题翻译：适应定时同步的频率跟踪
公开(公告)号：US20070217525A1
公开(公告)日：2007-09-20
申请号：US11376986
申请日：2006-03-15
申请人： Bojan Vrcelj , Raghuraman Krishnamoorthi , Seong Chung , Fuyun Ling
发明人： Bojan Vrcelj , Raghuraman Krishnamoorthi , Seong Chung , Fuyun Ling
IPC分类号： H04K1/10 , H04L27/06
CPC分类号： H04L27/2657 , H04L27/2607 , H04L27/2665 , H04L27/2678 , H04L27/2695
摘要： A frequency tracking method and apparatus is provided. A receiver receives OFDM symbols and determines associated frequency offset. A frequency error estimator selects a cross correlation window for determining frequency offset based on timing offset. A symbol timing estimator is used to determine the timing offset.
摘要翻译：提供了一种频率跟踪方法和装置。接收机接收OFDM符号并确定相关的频率偏移。频率误差估计器基于定时偏移来选择用于确定频率偏移的互相关窗口。使用符号定时估计器来确定定时偏移。

74. 发明申请

US20060250937A1 Method for transmission of time division multiplexed pilot symbols to aid channel estimation, time synchronization, and AGC bootstrapping in a multicast wireless system 有权
公开(公告)号：US20060250937A1
公开(公告)日：2006-11-09
申请号：US11372930
申请日：2006-03-09
申请人： Michael Wang , Bojan Vrcelj , Krishna Mukkavilli , Raghuraman Krishnamoorthi , Ashok Mantravadi
发明人： Michael Wang , Bojan Vrcelj , Krishna Mukkavilli , Raghuraman Krishnamoorthi , Ashok Mantravadi
IPC分类号： H04J11/00
CPC分类号： H04L27/2613 , H04L5/0007 , H04L5/0048 , H04L25/023
摘要： Systems and methods are provided for the transmission of waveforms to aid channel estimation, timing synchronization, and AGC bootstrapping in a wireless network. The method includes inserting at least one TDM pilot symbol located at a transition between wide area and local area waveforms to facilitate decoding of the transmission block.

75. 发明申请

US20060248135A1 Fast fourier transform twiddle multiplication 失效
标题翻译：快速傅立叶变换旋转乘法
公开(公告)号：US20060248135A1
公开(公告)日：2006-11-02
申请号：US11373433
申请日：2006-03-10
申请人： Kevin Cousineau , Raghuraman Krishnamoorthi
发明人： Kevin Cousineau , Raghuraman Krishnamoorthi
IPC分类号： G06F17/14
CPC分类号： H04L5/0064 , G06F17/142 , H04L5/0007 , H04L5/0048 , H04L5/0083 , H04L25/022 , H04L25/0226 , H04L27/265 , H04L27/2656
摘要： An FFT engine implementing a cycle count method of applying twiddle multiplications in multi-stages. When implementing a multistage FFT, the intermediate values need to be multiplied by various twiddle factors. The FFT engine utilizes a minimal number of multipliers to perform the twiddle multiplications in an efficient pipeline. Optimizing a number of complex multipliers based on an FFT radix and a number of values in each row of memory allows the FFT function to be performed using a reasonable amount of area and in a minimal number of cycles. Strategic ordering and grouping of the values allows the FFT operation to be performed in a fewer number of cycles.
摘要翻译：实现循环计数法的FFT引擎，用于多阶段应用旋转乘法。当实现多级FFT时，中间值需要乘以各种旋转因子。 FFT引擎利用最少数量的乘法器在有效的管道中执行旋转乘法。基于每一行存储器中的FFT基数和多个值来优化多个复数乘法器允许使用合理的面积和最小数量的周期来执行FFT功能。这些值的策略排序和分组允许以更少的周期执行FFT运算。

76. 发明申请

US20060227910A1 Receiver DC offset correction 审中-公开
标题翻译：接收机DC偏移校正
公开(公告)号：US20060227910A1
公开(公告)日：2006-10-12
申请号：US11373611
申请日：2006-03-09
申请人： Nangavalli Ramasubramanian , Raghuraman Krishnamoorthi , Krishna Mukkavilli
发明人： Nangavalli Ramasubramanian , Raghuraman Krishnamoorthi , Krishna Mukkavilli
IPC分类号： H03D1/04
CPC分类号： H04L25/06 , H03D3/006 , H03D3/008 , H04B1/30 , H04L27/38
摘要： A system and method are provided for correcting direct current (dc) offset in a wireless communications receiver. The method disconnects the mixer signal input from a received communication signal in an initialization state. An analog signal is accepted from the mixer output and converted into digital signal. A fine correction value is generated and subtracted from the digital signal. Thus, the digital signal amplitude in minimized in response to the initial fine correction value. In a communication state, the communication signals are received at the mixer signal input. The fine correction value is subtracted from a converted digital communication signal, so that the digital communication signal is supplied with a fine corrected dc offset. The method may also generate a coarse correction value to adjust mixer current in the initialization state, and a tracking correction value in the communication state.
摘要翻译：提供了用于校正无线通信接收机中的直流（dc）偏移的系统和方法。该方法在初始化状态下断开来自接收到的通信信号的混频信号输入。模拟信号从混频器输出接受并转换为数字信号。产生精细校正值并从数字信号中减去。因此，响应于初始精细校正值而最小化的数字信号幅度。在通信状态下，在混频器信号输入端接收通信信号。从转换的数字通信信号中减去精细校正值，从而向数字通信信号提供精细校正的直流偏移。该方法还可以产生粗调校正值以调整初始化状态下的混频器电流，以及通信状态下的跟踪校正值。

77. 发明申请

US20060215540A1 Efficient employment of digital upsampling using IFFT in OFDM systems for simpler analog filtering 有权
标题翻译：在OFDM系统中有效利用使用IFFT的数字上采样进行更简单的模拟滤波
公开(公告)号：US20060215540A1
公开(公告)日：2006-09-28
申请号：US11373001
申请日：2006-03-09
申请人： Raghuraman Krishnamoorthi , Fuyun Ling , Rajiv Vijayan
发明人： Raghuraman Krishnamoorthi , Fuyun Ling , Rajiv Vijayan
IPC分类号： H04J11/00
CPC分类号： H04L27/2644
摘要： Systems and methods are provided for transmitting OFDM information via IFFT up-sampling components that transmit data at a higher sampling rate than conventional systems to simplify filter requirements and mitigate leakage between symbols. In one embodiment, an NL point IFFT is performed on a zero inserted set of frequency domain symbols. In another embodiment, the NL point IFFT is further optimized by exploiting the fact that (N−1) L of the frequency domain symbols are zero. This enables an embodiment that consists of a pre-processor that multiplies the input samples by complex phase factors, followed by L point IFFTs.
摘要翻译：提供了系统和方法，用于通过IFFT上采样组件传输OFDM信息，该组件以比常规系统更高的采样速率传输数据，以简化滤波器要求并减轻符号之间的泄漏。在一个实施例中，对零插入的频域符号组执行NL点IFFT。在另一个实施例中，通过利用频域符号的（N-1）L为零的事实进一步优化NL点IFFT。这使得能够由预处理器组成的实施例，该预处理器将输入样本乘以复相位因子，随后是L点IFFT。

78. 发明申请

US20050063298A1 Synchronization in a broadcast OFDM system using time division multiplexed pilots 审中-公开
标题翻译：使用时分复用导频的广播OFDM系统中的同步
公开(公告)号：US20050063298A1
公开(公告)日：2005-03-24
申请号：US10931324
申请日：2004-08-31
申请人： Fuyun Ling , Alok Gupta , Raghuraman Krishnamoorthi , Ramaswamy Murali , Rajiv Vijayan , Bojan Vrcelj
发明人： Fuyun Ling , Alok Gupta , Raghuraman Krishnamoorthi , Ramaswamy Murali , Rajiv Vijayan , Bojan Vrcelj
IPC分类号： H04B3/10 , H04J20060101 , H04J1/16 , H04J11/00
CPC分类号： H04L27/2657 , H04L5/005 , H04L25/022 , H04L27/2613 , H04L27/2662 , H04L27/2665 , H04L2027/003
摘要： In an OFDM system, a transmitter broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least S1 identical pilot-1 sequences of length L1 and (2) an OFDM symbol for the second TDM pilot contains at least S2 identical pilot-2 sequences of length L2, where L2>L1, S1·L1=N, and S2·L2=N. The transmitter may also broadcast an FDM pilot. A receiver processes the first TDM pilot to obtain frame timing (e.g., by performing correlation between different pilot-1 sequences) and further processes the second TDM pilot to obtain symbol timing (e.g., by detecting for the start of a channel impulse response estimate derived from the second TDM pilot).
摘要翻译：在OFDM系统中，发射机在第一组子带上广播第一TDM导频，随后在每帧中的第二组子带上接收第二TDM导频。每个组中的子带从N个总子带中选出，使得（1）第一TDM导频的OFDM符号包含长度为L1的至少S1个相同的导频1序列，以及（2）第二TDM导频的OFDM符号包含至少S2个长度为L2的导频-2序列，其中L2> L1，S1.L1 = N，S2.L2 = N。发射机还可以广播FDM导频。接收机处理第一TDM导频以获得帧定时（例如，通过执行不同导频-1序列之间的相关）并且进一步处理第二TDM导频以获得符号定时（例如，通过检测导出的信道脉冲响应估计的开始从第二TDM导频）。

79. 发明授权

US09036567B2 Logical channel mapping for increased utilization of transmission resources 有权
标题翻译：用于增加传输资源利用率的逻辑信道映射
公开(公告)号：US09036567B2
公开(公告)日：2015-05-19
申请号：US12699596
申请日：2010-02-03
申请人： Raghuraman Krishnamoorthi , Gordon Kent Walker , Fuyun Ling
发明人： Raghuraman Krishnamoorthi , Gordon Kent Walker , Fuyun Ling
IPC分类号： H04W72/04 , H04N21/63 , H04N21/2383 , H04N21/2385 , H04N21/438
CPC分类号： H04N21/631 , H04N21/2383 , H04N21/2385 , H04N21/4382
摘要： Methods, systems, and apparatus, including computer programs encoded on computer readable storage media, for increasing utilization of transmission resources by mapping data from a block of layered codec data onto a plurality of logical channels for transmission of the mapped data. Resource utilization may also be improved by mapping data from at least two layers of a block of layered of codec data onto a logical channel that supports only a single data channel carried by a transmit modulation scheme.
摘要翻译：方法，系统和装置，包括在计算机可读存储介质上编码的计算机程序，用于通过将来自分层编解码器数据块的数据映射到用于传输映射数据的多个逻辑信道上的数据来增加传输资源的利用。也可以通过将来自编解码器数据分层的至少两层的数据映射到仅支持由发送调制方案承载的单个数据信道的逻辑信道上来提高资源利用。

80. 发明授权

US09008198B2 Methods and apparatus for timing synchronization based on transitional pilot symbols 有权
标题翻译：基于过渡导频符号的定时同步的方法和装置
公开(公告)号：US09008198B2
公开(公告)日：2015-04-14
申请号：US11765428
申请日：2007-06-19
申请人： Bojan Vrcelj , Krishna Kiran Mukkavilli , Ashok Mantravadi , Raghuraman Krishnamoorthi
发明人： Bojan Vrcelj , Krishna Kiran Mukkavilli , Ashok Mantravadi , Raghuraman Krishnamoorthi
IPC分类号： H04K1/10 , H04L27/28 , H04L27/26 , H04L5/00 , H04L7/08 , H04L25/02
CPC分类号： H04L27/2662 , H04L5/0048 , H04L7/08 , H04L25/0216 , H04L25/023 , H04L27/2613 , H04L27/2675 , H04L27/2695
摘要： Methods and apparatus for timing synchronization based on transitional pilot symbols. In an aspect, a method is provided for time tracking synchronization in an OFDM system. The method includes receiving at least one TDM pilot symbol comprising a plurality of modulated sub-carriers that are configured to provide a channel estimate having a length that extends up to a duration of an FFT used for data transmission. The method also includes determining one or both of an instantaneous and averaged channel estimates from the plurality of modulated sub-carriers, and calculating a timing offset based on one or both of the channel estimates. An apparatus includes a receiver configured to receive the at least one TDM pilot symbol, a channel estimator configured to determine the instantaneous and averaged channel estimates, and a time synchronizer configured to calculate a timing offset based on the channel estimates.
摘要翻译：基于过渡导频符号的定时同步的方法和装置。在一方面，提供了一种用于OFDM系统中的时间跟踪同步的方法。该方法包括：接收至少一个TDM导频符号，该TDM导频符号包括多个经调制的子载波，其被配置为提供具有延伸到用于数据传输的FFT的持续时间的长度的信道估计。该方法还包括确定来自多个调制子载波的瞬时和平均信道估计中的一个或两个，以及基于信道估计中的一个或两个来计算定时偏移。一种装置包括被配置为接收所述至少一个TDM导频符号的接收机，被配置为确定瞬时和平均信道估计的信道估计器，以及被配置为基于信道估计来计算定时偏移的时间同步器。

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