公开(公告)号：US20050135308A1

公开(公告)日：2005-06-23

申请号：US10968614

申请日：2004-10-18

申请人： Rajiv Vijayan ,  Gordon Walker ,  Raghu Krishnamoorthi ,  Ramaswamy Murali

发明人： Rajiv Vijayan ,  Gordon Walker ,  Raghu Krishnamoorthi ,  Ramaswamy Murali

IPC分类号： H04L27/28

CPC分类号： H04L27/0008 ,  H04L5/0007 ,  H04L5/0041 ,  H04L5/0044 ,  H04L5/0051 ,  H04L5/0064 ,  H04L25/022 ,  H04L25/0226 ,  H04L25/0228 ,  H04L27/2604 ,  H04L27/2605 ,  H04L27/2647 ,  Y02D70/10

摘要： Techniques for multiplexing multiple data streams using frequency division multiplexing (FDM) in an OFDM system are described. M disjoint “interlaces” are formed with U usable subbands. Each interlace is a different set of S subbands, where U=M·S. The subbands for each interlace are interlaced with the subbands for each of the other M−1 interlaces. M slots may be defined for each symbol period and assigned slot indices 1 through M. The slot indices may be mapped to interlaces such that (1) frequency diversity is achieved for each slot index and (2) the interlaces used for pilot transmission have varying distances to the interlaces used for each slot index, which improves channel estimation performance. Each data stream may be processed as data packets of a fixed size, and different numbers of slots may be used for each data packet depending on the coding and modulation scheme used for the data packet.

摘要翻译： 描述了在OFDM系统中使用频分复用（FDM）来复用多个数据流的技术。 M个不相交的“交错”与U个可用的子带形成。 每个交错是S个子带的不同集合，其中U = M.S。 用于每个交错的子带与用于其它M-1交错的每个子带进行隔行扫描。 可以为每个符号周期和分配的时隙索引1到M定义M个时隙。时隙索引可以被映射到交织，使得（1）针对每个时隙索引实现频率分集，以及（2）用于导频传输的交织具有不同的 到每个时隙索引用于交织的距离，这提高了信道估计性能。 每个数据流可以被处理为固定大小的数据分组，并且根据用于数据分组的编码和调制方案，每个数据分组可以使用不同数量的时隙。

公开(公告)号：US20050058089A1

公开(公告)日：2005-03-17

申请号：US10932586

申请日：2004-09-01

申请人： Rajiv Vijayan ,  Aamod Khandekar ,  Fuyun Ling ,  Gordon Walker ,  Ramaswamy Murali

发明人： Rajiv Vijayan ,  Aamod Khandekar ,  Fuyun Ling ,  Gordon Walker ,  Ramaswamy Murali

IPC分类号： H04H20/00 ,  H04J3/24 ,  H04L1/00 ,  H04L5/02 ,  H04L5/06 ,  H04L25/02 ,  H04L27/26 ,  H04W4/06 ,  H04W28/06 ,  H04W72/04

CPC分类号： H04W52/0209 ,  H04B7/12 ,  H04L1/0057 ,  H04L1/0065 ,  H04L1/0071 ,  H04L1/0083 ,  H04L5/0007 ,  H04L5/0044 ,  H04L5/0048 ,  H04L5/0053 ,  H04L5/06 ,  H04L25/0224 ,  H04L27/2602 ,  H04N21/2383 ,  H04N21/4382 ,  H04N21/6112 ,  H04W4/06 ,  H04W28/06 ,  H04W72/04 ,  Y02D70/166 ,  Y02D70/168 ,  Y02D70/442

摘要： Techniques for multiplexing and transmitting multiple data streams are described. Transmission of the multiple data streams occurs in “super-frames”. Each super-frame has a predetermined time duration and is further divided into multiple (e.g., four) frames. Each data block for each data stream is outer encoded to generate a corresponding code block. Each code block is partitioned into multiple subblocks, and each data packet in each code block is inner encoded and modulated to generate modulation symbols for the packet. The multiple subblocks for each code block are transmitted in the multiple frames of the same super-frame, one subblock per frame. Each data stream is allocated a number of transmission units in each super-frame and is assigned specific transmission units to achieve efficient packing. A wireless device can select and receive individual data streams.

摘要翻译： 描述用于复用和传输多个数据流的技术。 多个数据流的传输发生在“超帧”中。 每个超帧具有预定的持续时间并进一步分为多个（例如，四个）帧。 每个数据流的每个数据块被外部编码以生成相应的代码块。 每个码块被划分成多个子块，并且每个码块中的每个数据分组被内部编码和调制以产生分组的调制符号。 每个码块的多个子块在相同超帧的多个帧中传送，每帧一个子块。 每个数据流在每个超帧中被分配多个传输单元，并被分配特定的传输单元以实现有效的打包。 无线设备可以选择和接收各个数据流。

公开(公告)号：US20050020201A1

公开(公告)日：2005-01-27

申请号：US10616585

申请日：2003-07-09

申请人： Richard Lane ,  Gordon Walker ,  Ramaswamy Murali ,  Chinnappa Ganapathy

发明人： Richard Lane ,  Gordon Walker ,  Ramaswamy Murali ,  Chinnappa Ganapathy

IPC分类号： H04L29/06 ,  H04H1/00

CPC分类号： H04L65/4076 ,  H04L29/06027 ,  H04L65/607

摘要： In addition to global index chunks that indicate the order of program portions in a multimedia stream carrying multiple multiplexed programs, index blocks are provided in data chunks of the stream that point to times when particular program portions arrive. This information can be used at the physical or transport layer of a wireless battery-powered receiver by, e.g., a simple state machine to energize the analog receiving circuitry only for as long as necessary to receive information pertaining to a desired program, thereby conserving battery power.

摘要翻译： 除了指示携带多个多路复用程序的多媒体流中的程序部分的顺序的全局索引块之外，索引块被提供在指向特定程序部分到达的时间的数据流的数据块中。 该信息可以通过例如简单的状态机在无线电池供电的接收机的物理层或传输层上使用，以仅在需要接收与所需节目有关的信息的情况下激励模拟接收电路，从而节省电池 功率。

公开(公告)号：US20090175210A1

公开(公告)日：2009-07-09

申请号：US12180305

申请日：2008-07-25

申请人： Rajiv Vijayan ,  Aamod Khandekar ,  Fuyun Ling ,  Gordon Kent Walker ,  Ramaswamy Murali

发明人： Rajiv Vijayan ,  Aamod Khandekar ,  Fuyun Ling ,  Gordon Kent Walker ,  Ramaswamy Murali

IPC分类号： H04H20/71 ,  H04W72/04 ,  H04L27/28 ,  H04J11/00

CPC分类号： H04L5/0007 ,  H04L1/0065 ,  H04L1/0083 ,  H04L5/0039 ,  H04L5/0041 ,  H04L5/0044 ,  H04L5/0048 ,  H04L5/0064 ,  H04L5/0094

摘要： Techniques for multiplexing and transmitting multiple data streams are described. Transmission of the multiple data streams occurs in “super-frames”. Each super-frame has a predetermined time duration and is further divided into multiple (e.g., four) frames. Each data block for each data stream is outer encoded to generate a corresponding code block. Each code block is partitioned into multiple subblocks, and each data packet in each code block is inner encoded and modulated to generate modulation symbols for the packet. The multiple subblocks for each code block are transmitted in the multiple frames of the same super-frame, one subblock per frame. Each data stream is allocated a number of transmission units in each super-frame and is assigned specific transmission units to achieve efficient packing. A wireless device can select and receive individual data streams.

摘要翻译： 描述用于复用和传输多个数据流的技术。 多个数据流的传输发生在“超帧”中。 每个超帧具有预定的持续时间并进一步分为多个（例如，四个）帧。 每个数据流的每个数据块被外部编码以生成相应的代码块。 每个码块被划分成多个子块，并且每个码块中的每个数据分组被内部编码和调制以产生分组的调制符号。 每个码块的多个子块在相同超帧的多个帧中传送，每帧一个子块。 每个数据流在每个超帧中被分配多个传输单元，并被分配特定的传输单元以实现有效的打包。 无线设备可以选择和接收各个数据流。

公开(公告)号：US07336683B1

公开(公告)日：2008-02-26

申请号：US10464361

申请日：2003-06-17

申请人： Donald Brian Eidson ,  Abraham Krieger ,  Ramaswamy Murali

发明人： Donald Brian Eidson ,  Abraham Krieger ,  Ramaswamy Murali

IPC分类号： H04J3/00

CPC分类号： H04B7/18595 ,  H04L1/0089

摘要： An exemplary satellite communication system comprises a service provider unit communicably coupled to a number of subscriber units via satellite transmission. The service provider unit includes an encoder configured to encode source data into a serial transmit sequence, and is further capable of supporting at least two modes of operation. The serial transmit sequence includes a first unique word identifying a first mode of operation, and is followed by a first payload packet having a first number of channel symbols corresponding to a source packet encoded in accordance with the first mode of operation identified by the first unique word. The first payload packet is encapsulated by two unique words and the time interval between the two unique words is used to determine the first mode of operation identified by the first unique word.

摘要翻译： 示例性卫星通信系统包括通过卫星传输可通信地耦合到多个用户单元的服务提供商单元。 服务提供商单元包括被配置为将源数据编码为串行发送序列的编码器，并且还能够支持至少两种操作模式。 串行发送序列包括识别第一操作模式的第一唯一字，并且后面是第一有效载荷分组，其具有对应于根据由第一唯一的第一唯一标识的第一操作模式编码的源分组的第一数量的信道符号 字。 第一个有效载荷包被两个唯一字封装，并且两个唯一字之间的时间间隔用于确定由第一个唯一字识别的第一操作模式。

公开(公告)号：US07221680B2

公开(公告)日：2007-05-22

申请号：US10932586

申请日：2004-09-01

申请人： Rajiv Vijayan ,  Aamod Khandekar ,  Fuyun Ling ,  Gordon Kent Walker ,  Ramaswamy Murali

发明人： Rajiv Vijayan ,  Aamod Khandekar ,  Fuyun Ling ,  Gordon Kent Walker ,  Ramaswamy Murali

IPC分类号： H04B7/216

CPC分类号： H04W52/0209 ,  H04B7/12 ,  H04L1/0057 ,  H04L1/0065 ,  H04L1/0071 ,  H04L1/0083 ,  H04L5/0007 ,  H04L5/0044 ,  H04L5/0048 ,  H04L5/0053 ,  H04L5/06 ,  H04L25/0224 ,  H04L27/2602 ,  H04N21/2383 ,  H04N21/4382 ,  H04N21/6112 ,  H04W4/06 ,  H04W28/06 ,  H04W72/04 ,  Y02D70/166 ,  Y02D70/168 ,  Y02D70/442

摘要： Techniques for multiplexing and transmitting multiple data streams are described. Transmission of the multiple data streams occurs in “super-frames”. Each super-frame has a predetermined time duration and is further divided into multiple (e.g., four) frames. Each data block for each data stream is outer encoded to generate a corresponding code block. Each code block is partitioned into multiple subblocks, and each data packet in each code block is inner encoded and modulated to generate modulation symbols for the packet. The multiple subblocks for each code block are transmitted in the multiple frames of the same super-frame, one subblock per frame. Each data stream is allocated a number of transmission units in each super-frame and is assigned specific transmission units to achieve efficient packing. A wireless device can select and receive individual data streams.

摘要翻译： 描述用于复用和传输多个数据流的技术。 多个数据流的传输发生在“超帧”中。 每个超帧具有预定的持续时间并进一步分为多个（例如，四个）帧。 每个数据流的每个数据块被外部编码以生成相应的代码块。 每个码块被划分成多个子块，并且每个码块中的每个数据分组被内部编码和调制以产生分组的调制符号。 每个码块的多个子块在相同超帧的多个帧中传送，每帧一个子块。 每个数据流在每个超帧中被分配多个传输单元，并被分配特定的传输单元以实现有效的打包。 无线设备可以选择和接收各个数据流。

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）。

公开(公告)号：US06810502B2

公开(公告)日：2004-10-26

申请号：US09865958

申请日：2001-05-25

申请人： Donald Brian Eidson ,  Abraham Krieger ,  Ramaswamy Murali

发明人： Donald Brian Eidson ,  Abraham Krieger ,  Ramaswamy Murali

IPC分类号： H03M1303

CPC分类号： H04L1/005 ,  H03M13/09 ,  H03M13/15 ,  H03M13/2936 ,  H03M13/2948 ,  H03M13/2972 ,  H03M13/3776 ,  H03M13/3994 ,  H04L1/0054 ,  H04L1/0061 ,  H04L1/0065 ,  H04L1/0066

摘要： Iterative decoder employing multiple external code error checks to lower the error floor and/or improve decoding performance. Data block redundancy, sometimes via a cyclic redundancy check (CRC) or Reed Solomon (RS) code, enables enhanced iterative decoding performance. Improved decoding performance is achieved during interim iterations before the final iteration. A correctly decoded CRC block, indicating a decoded segment is correct with a high degree of certainty, assigns a very high confidence level to the bits in this segment and is fed back to inner and/or outer decoders (with interleaving, when appropriate) for improved iterative decoding. High confidence bits may be scattered throughout inner decoded frames to influence other bit decisions in subsequent iterations. Turbo decoders typically operate relatively well at regions where the BER is high; the invention improves iterative decoder operation at lower BERs, lowering the ‘BER floor’ that is sometimes problematic with conventional turbo decoders.

摘要翻译： 迭代解码器采用多个外部码错误检查来降低错误帧和/或提高解码性能。 有时通过循环冗余校验（CRC）或Reed Solomon（RS）代码进行数据块冗余，可实现增强的迭代解码性能。 在最终迭代之前的中间迭代期间，可以实现改进的解码性能。 一个正确解码的CRC块，指示解码的段是高度确定的正确的，为该段中的位分配非常高的置信度水平，并将其反馈给内部和/或外部解码器（适当时进行交织），以便 改进的迭代解码。 高置信位可能散布在整个内部解码帧中，以影响后续迭代中的其他位决策。 Turbo解码器通常在BER高的区域相对较好地工作; 本发明改进了在较低BER下的迭代解码器操作，降低了常规turbo解码器有时成问题的“BER地面”。

公开(公告)号：US06795512B1

公开(公告)日：2004-09-21

申请号：US09715877

申请日：2000-11-17

申请人： Donald Brian Eidson ,  Ramaswamy Murali ,  Abraham Krieger ,  Magnus H. Berggren

发明人： Donald Brian Eidson ,  Ramaswamy Murali ,  Abraham Krieger ,  Magnus H. Berggren

IPC分类号： H04L2706

CPC分类号： H04L25/067 ,  H04L1/0054 ,  H04L1/0055 ,  H04L25/025 ,  H04L2025/03598

摘要： A system for carrier phase tracking of symbols. In an embodiment employing a feedback structure, a symbol derotator pre-rotates a symbol by a derotation phase. A symbol and reliability estimation engine provides, responsive to the pre-rotated symbol, an estimate of the symbol and a reliability metric for the estimate. A tracking loop module determines a residual between the pre-rotated symbol and the symbol estimate, weights the residual by the reliability metric for the estimate, and determines a phase offset estimate responsive to the weighted residual. An accumulator then determines a next derotation phase responsive to the phase offset estimate. In an embodiment employing a feedforward structure, a symbol and reliability estimation engine provides an estimate of a symbol and a reliability metric for the estimate. A tracking loop module determines a residual between the symbol and the symbol estimate, weights the residual by the reliability metric for the estimate, and determines a derotation phase responsive to the weighted residual.

摘要翻译： 符号载波相位跟踪系统。 在采用反馈结构的实施例中，符号解旋器通过解旋相预先旋转符号。 符号和可靠性估计引擎响应于预旋转符号提供符号的估计和估计的可靠性度量。 跟踪环模块确定预旋转符号和符号估计之间的残差，将残差加权用于估计的可靠性度量，并且响应于加权残差确定相位偏移估计。 然后，累加器确定响应于相位偏移估计的下一个解旋相位。 在采用前馈结构的实施例中，符号和可靠性估计引擎提供用于估计的符号估计和可靠性度量。 跟踪循环模块确定符号和符号估计之间的残差，将残差加权估计的可靠性度量，并根据加权残差确定解旋相位。