PHASE CORRECTION FOR OFDM AND MIMO TRANSMISSIONS
    1.
    发明申请
    PHASE CORRECTION FOR OFDM AND MIMO TRANSMISSIONS 有权
    OFDM和MIMO传输的相位校正

    公开(公告)号:US20080056305A1

    公开(公告)日:2008-03-06

    申请号:US11751471

    申请日:2007-05-21

    IPC分类号: H04B3/10

    摘要: Techniques for performing phase correction for wireless communication are described. Received pilot symbols and received data symbols may be obtained from an orthogonal frequency division multiplexing (OFDM) and/or multiple-input multiple-output (MIMO) transmission. First phase information is obtained based upon the received pilot symbols. Second phase information is obtained based upon the received data symbols. The phase of the received data symbols is corrected based upon the first and second phase information (directly and/or indirectly). For example, the phase of the received data symbols may be corrected based upon the first phase information, detection may be performed on the phase corrected data symbols to obtain estimated data symbols, the second phase information may be obtained based upon the estimated data symbols, and the phase of the estimated data symbols may be corrected based upon the second phase information. The phase correction may also be performed in other manners.

    摘要翻译: 描述用于执行无线通信的相位校正的技术。 可以从正交频分复用(OFDM)和/或多输入多输出(MIMO)传输中获得接收到的导频符号和接收的数据符号。 基于接收到的导频符号获得第一相位信息。 基于接收到的数据符号获得第二相位信息。 基于第一和第二相位信息(直接和/或间接地)校正接收到的数据符号的相位。 例如,可以基于第一相位信息来校正接收到的数据符号的相位,可以对相位校正数据符号执行检测以获得估计的数据符号,可以基于估计的数据符号获得第二相位信息, 并且可以基于第二相位信息来校正估计数据符号的相位。 相位校正也可以以其他方式进行。

    METHOD AND APPARATUS FOR ALLOCATING DOWNLINK RESOURCES IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM
    2.
    发明申请
    METHOD AND APPARATUS FOR ALLOCATING DOWNLINK RESOURCES IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM 有权
    用于在多输入多输出(MIMO)通信系统中分配下行链路资源的方法和装置

    公开(公告)号:US20080013638A1

    公开(公告)日:2008-01-17

    申请号:US11766362

    申请日:2007-06-21

    IPC分类号: H04L27/28

    摘要: Techniques to schedule downlink data transmission to a number of terminals in a wireless communication system. In one method, one or more sets of terminals are formed for possible data transmission, with each set including a unique combination of one or more terminals and corresponding to a hypothesis to be evaluated. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to specific assignments of a number of transmit antennas to the one or more terminals in the hypothesis. The performance of each sub-hypothesis is then evaluated, and one of the evaluated sub-hypotheses is selected based on their performance. The terminal(s) in the selected sub-hypothesis are then scheduled for data transmission, and data is thereafter coded, modulated, and transmitted to each scheduled terminal from one or more transmit antennas assigned to the terminal.

    摘要翻译: 将无线通信系统中的下行链路数据传输调度到多个终端的技术。 在一种方法中,形成一组或多组终端用于可能的数据传输,每组包括一个或多个终端的唯一组合,并对应于待评估的假设。 可以针对每个假设进一步形成一个或多个子假设,其中每个子假设对应于假设中的一个或多个终端的多个发射天线的特定分配。 然后评估每个子假设的性能,并根据其性能选择评估的子假设之一。 然后将所选子假设中的终端调度用于数据传输,然后将数据从分配给终端的一个或多个发射天线编码,调制并发送到每个调度终端。

    Sphere detection and rate selection for a MIMO transmission
    3.
    发明申请
    Sphere detection and rate selection for a MIMO transmission 有权
    用于MIMO传输的球体检测和速率选择

    公开(公告)号:US20070162827A1

    公开(公告)日:2007-07-12

    申请号:US11349367

    申请日:2006-02-06

    IPC分类号: H03M13/00

    摘要: Techniques for performing sphere detection to recover data symbols sent in a MIMO transmission are described. In an aspect, sphere detection is performed for data symbols generated with at least two modulation schemes. In another aspect, sphere detection is performed for the data symbols in an order determined based on at least one attribute of the data symbols, which may be error probabilities, modulation schemes, and/or link margins for the data symbols. In yet another aspect, rates for multiple data streams detected with sphere detection are selected based on channel state information. Signal qualities of the data streams may be estimated based on the channel state information, e.g., (1) an upper triangular matrix used for sphere detection and/or (2) an assumption that interference from data streams already detected is canceled. The rates for the data streams may be selected based on the estimated signal qualities.

    摘要翻译: 描述了用于执行球体检测以恢复在MIMO传输中发送的数据符号的技术。 在一个方面,对用至少两个调制方案产生的数据符号执行球体检测。 在另一方面,以数据符号的至少一个属性确定的顺序对数据符号执行球体检测,数据符号可以是数据符号的错误概率,调制方案和/或链接余量。 在另一方面,基于信道状态信息选择用球检测检测的多个数据流的速率。 可以基于信道状态信息来估计数据流的信号质量,例如(1)用于球体检测的上三角矩阵和/或(2)已经检测到的来自数据流的干扰被消除的假设。 可以基于估计的信号质量来选择数据流的速率。

    Efficient computation for eigenvalue decomposition and singular value decomposition of matrices
    4.
    发明申请
    Efficient computation for eigenvalue decomposition and singular value decomposition of matrices 有权
    矩阵特征值分解和奇异值分解的有效计算

    公开(公告)号:US20060106902A1

    公开(公告)日:2006-05-18

    申请号:US11096839

    申请日:2005-03-31

    IPC分类号: G06F15/00

    摘要: For eigenvalue decomposition, a first set of at least one variable is derived based on a first matrix being decomposed and using Coordinate Rotational Digital Computer (CORDIC) computation. A second set of at least one variable is derived based on the first matrix and using a look-up table. A second matrix of eigenvectors of the first matrix is then derived based on the first and second variable sets. To derive the first variable set, CORDIC computation is performed on an element of the first matrix to determine the magnitude and phase of this element, and CORDIC computation is performed on the phase to determine the sine and cosine of this element. To derive the second variable set, intermediate quantities are derived based on the first matrix and used to access the look-up table.

    摘要翻译: 对于特征值分解,基于正在分解的第一矩阵并使用坐标旋转数字计算机(CORDIC)计算来导出至少一个变量的第一组。 基于第一矩阵并使用查找表导出第二组至少一个变量。 然后基于第一和第二变量集导出第一矩阵的特征向量的第二矩阵。 为了导出第一变量集,对第一矩阵的元素执行CORDIC计算,以确定该元素的幅度和相位,并且在相位上执行CORDIC计算以确定该元素的正弦和余弦。 为了导出第二变量集,基于第一矩阵导出中间量并用于访问查找表。

    Power-efficient multi-antenna wireless device
    5.
    发明申请
    Power-efficient multi-antenna wireless device 有权
    功率高效的多天线无线设备

    公开(公告)号:US20050250452A1

    公开(公告)日:2005-11-10

    申请号:US11047917

    申请日:2005-01-31

    IPC分类号: H04J99/00 H04B1/16 H04B1/00

    摘要: A power-efficient wireless device is equipped with multiple (N) antennas. Each antenna is associated with a transmitter unit and a receiver unit. The wireless device also has processing units used to perform various digital processing tasks. The transmitter units, receiver units, and processing units may be selectively enabled or disabled. In an idle state, the wireless device may enable only a subset (e.g., one) of the N receiver units and one or few processing units for signal detection and acquisition. For active communication, the wireless device may enable Ntx transmitter units for data transmission and/or Nrx receiver units for data reception, where 1≧Ntx≧N and 1≧Nrx≧N. The enabled processing units may also be clocked at a lower frequency whenever data is transmitted or received at a data rate lower than the highest data rate. The wireless device may go to sleep whenever possible to conserve power.

    摘要翻译: 功率高效的无线设备配备有多(N)个天线。 每个天线与发射机单元和接收机单元相关联。 无线设备还具有用于执行各种数字处理任务的处理单元。 可以选择性地启用或禁用发射机单元,接收机单元和处理单元。 在空闲状态下,无线设备可以仅使得N个接收机单元中的子集(例如,一个)和用于信号检测和获取的一个或几个处理单元。 对于主动通信,无线设备可以使用用于数据传输的N x x> transmitter transmitter transmitter transmitter transmitter and and or or or or or or x x x x x x x x x x x x x x x x x x x x x x x > = N和1> = N = N。 每当以低于最高数据速率的数据速率发送或接收数据时,启用的处理单元也可以以更低的频率被计时。 无线设备可能会尽可能地睡眠以节省电力。

    Wireless communication network with extended coverage range
    7.
    发明申请
    Wireless communication network with extended coverage range 有权
    无线通信网络覆盖范围扩大

    公开(公告)号:US20060285604A1

    公开(公告)日:2006-12-21

    申请号:US11158494

    申请日:2005-06-21

    IPC分类号: H04L27/00 H04L1/02

    摘要: A wireless communication network supports 802.11b/g and a range extension mode, which supports at least one data rate lower than the lowest data rate in 802.11b/g. A transmitting station (which may be an access point or a user terminal) includes first and second processors. The first processor performs differential modulation and spectral spreading for a first set of at least one data rate (e.g., 1 and 2 Mbps) supported by 802.11b/g. The second processor performs forward error correction (FEC) encoding, symbol mapping, and spectral spreading for a second set of at least one data rate (e.g., 250, 500, and 1000 Kbps) supported by the range extension mode. The transmitting station can send a transmission at a data rate supported by either 802.11b/g or the range extension mode, e.g., depending on the desired coverage range for the transmission. A receiving station performs the complementary processing to recover the transmission.

    摘要翻译: 无线通信网络支持802.11b / g和范围扩展模式,其支持在802.11b / g中至少一个数据速率低于最低数据速率。 发送站(其可以是接入点或用户终端)包括第一和第二处理器。 第一处理器对由802.11b / g支持的至少一个数据速率(例如1和2Mbps)的第一组执行差分调制和频谱扩展。 第二处理器对范围扩展模式支持的至少一个数据速率(例如,250,500和1000Kbps)的第二组执行前向纠错(FEC)编码,符号映射和频谱扩展。 发射台可以以802.11b / g或范围扩展模式支持的数据速率发送传输,例如,取决于传输的期望覆盖范围。 接收站进行补充处理以恢复传输。

    Efficient computation of spatial filter matrices for steering transmit diversity in a MIMO communication system

    公开(公告)号:US20060002496A1

    公开(公告)日:2006-01-05

    申请号:US10882491

    申请日:2004-06-30

    IPC分类号: H04L1/02

    摘要: Techniques for efficiently computing spatial filter matrices are described. The channel response matrices for a MIMO channel may be highly correlated if the channel is relatively static over a range of transmission spans. In this case, an initial spatial filter matrix may be derived based on one channel response matrix, and a spatial filter matrix for each transmission span may be computed based on the initial spatial filter matrix and a steering matrix used for that transmission span. The channel response matrices may be partially correlated if the MIMO channel is not static but does not change abruptly. In this case, a spatial filter matrix may be derived for one transmission span l and used to derive an initial spatial filter matrix for another transmission span m. A spatial filter matrix for transmission span m may be computed based on the initial spatial filter matrix, e.g., using an iterative procedure.

    Coding scheme for a wireless communication system
    10.
    发明申请
    Coding scheme for a wireless communication system 有权
    无线通信系统的编码方案

    公开(公告)号:US20050276344A1

    公开(公告)日:2005-12-15

    申请号:US11208263

    申请日:2005-08-18

    摘要: Coding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of “transmission channels” at different information bit rates based on the channels' achieved SNR. A base code is used in combination with common or variable puncturing to achieve different coding rates required by the transmission channels. The data (i.e., information bits) for a data transmission is encoded with the base code, and the coded bits for each channel (or group of channels with the similar transmission capabilities) are punctured to achieve the required coding rate. The coded bits may be interleaved (e.g., to combat fading and remove correlation between coded bits in each modulation symbol) prior to puncturing. The unpunctured coded bits are grouped into non-binary symbols and mapped to modulation symbols (e.g., using Gray mapping). The modulation symbol may be “pre-conditioned” and prior to transmission.

    摘要翻译: 能够基于信道实现的SNR以不同的信息比特率在多个“传输信道”上发送数据的(例如,OFDM)通信系统的编码技术。 基本码与公共或可变的打孔组合使用以实现传输信道所需的不同的编码速率。 针对数据传输的数据(即,信息比特)用基本码进行编码,并且针对每个信道(或具有相似传输能力的信道组)的编码比特被打孔以实现所需的编码率。 在穿孔之前,编码比特可以被交织(例如,以抵消衰落并消除每个调制符号中的编码比特之间的相关性)。 未经穿孔的编码比特被分组成非二进制符号并映射到调制符号(例如,使用灰色映射)。 调制符号可以是“预调节”并且在传输之前。