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。

    Resource allocation for MIMO-OFDM communication systems

    公开(公告)号:US20060039312A1

    公开(公告)日:2006-02-23

    申请号:US11248890

    申请日:2005-10-11

    IPC分类号: H04B7/204

    摘要: Techniques to schedule terminals for data transmission on the downlink and/or uplink in a MIMO-OFDM system based on the spatial and/or frequency “signatures” of the terminals. A scheduler forms one or more sets of terminals for possible (downlink or uplink) data transmission for each of a number of frequency bands. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to (1) specific assignments of transmit antennas to the terminal(s) in the hypothesis (for the downlink) or (2) a specific order for processing the uplink data transmissions from the terminal(s) (for the uplink). The performance of each sub-hypothesis is then evaluated (e.g., based on one or more performance metrics). One sub-hypothesis is then selected for each frequency band based on the evaluated performance, and the one or more terminals in each selected sub-hypothesis are then scheduled for data transmission on the corresponding frequency band.

    Multiple-input, multiple-output (MIMO) systems with multiple transmission modes
    3.
    发明申请
    Multiple-input, multiple-output (MIMO) systems with multiple transmission modes 有权
    具有多种传输模式的多输入多输出(MIMO)系统

    公开(公告)号:US20050094598A1

    公开(公告)日:2005-05-05

    申请号:US10985400

    申请日:2004-11-10

    摘要: Techniques to transmit data on a number of transmission channels in a multi-channel communication system using multiple transmission schemes requiring less channel-state information (CSI). These schemes may include a partial-CSI transmission scheme that transmits a single data stream on each transmit antenna selected for use and a “beam-forming” transmission scheme that allocates all transmit power to a single transmission channel having the best performance. Each transmission scheme may provide good or near-optimum performance for a specific range of operating conditions (or operating SNRs). These multiple transmission schemes may then be combined in a piece-wise fashion to form a “multi-mode” transmission scheme that covers the full range of operating conditions supported by the MIMO system. The specific transmission scheme to be used for data transmission at any given moment would then be dependent on the specific operating condition experienced by the system at that moment.

    摘要翻译: 使用需要较少信道状态信息(CSI)的多个传输方案在多信道通信系统中在多个传输信道上传输数据的技术。 这些方案可以包括在被选择使用的每个发射天线上发送单个数据流的部分CSI传输方案以及将所有发射功率分配给具有最佳性能的单个传输信道的“波束形成”传输方案。 每个传输方案可以为特定范围的操作条件(或操作SNR)提供良好或接近最佳的性能。 然后,这些多个传输方案可以以分段方式组合以形成覆盖由MIMO系统支持的全部操作条件的“多模式”传输方案。 在任何给定时刻用于数据传输的具体传输方案将取决于系统在此刻经历的特定操作条件。

    Receiver structures for spatial spreading with space-time or space-frequency transmit diversity
    4.
    发明申请
    Receiver structures for spatial spreading with space-time or space-frequency transmit diversity 有权
    用于空间时空或空间 - 频率发射分集的空间扩展的接收机结构

    公开(公告)号:US20060050770A1

    公开(公告)日:2006-03-09

    申请号:US11042126

    申请日:2005-01-24

    IPC分类号: H04L1/02 H04B1/707

    摘要: A receiving entity obtains received symbols for a data transmission having at least one data symbol stream sent with space-time transmit diversity (STTD). The receiving entity derives an overall channel response matrix in accordance with the STTD encoding scheme used for the data transmission, derives a spatial filter matrix based on the overall channel response matrix, and performs spatial matched filtering on a vector of received symbols for each 2-symbol interval to obtain a vector of detected symbols for the 2-symbol interval. The receiving entity may perform post-processing (e.g., conjugation) on the detected symbols if needed. Alternatively, the receiving entity derives a spatial filter matrix based on an effective channel response matrix, performs spatial matched filtering on the received symbols for each symbol period to obtain detected symbols for that symbol period, and combines multiple estimates obtained for each data symbol sent with STTD.

    摘要翻译: 接收实体获得具有用空时传输分集(STTD)发送的至少一个数据符号流的数据传输的接收符号。 接收实体根据用于数据传输的STTD编码方案导出整体信道响应矩阵,基于整个信道响应矩阵导出空间滤波器矩阵,并且对每个2-信道的接收符号的向量执行空间匹配滤波, 符号间隔以获得用于2符号间隔的检测符号的向量。 如果需要,接收实体可以在检测到的符号上执行后处理(例如,共轭)。 或者,接收实体基于有效信道响应矩阵导出空间滤波器矩阵,对于每个符号周期对接收到的符号执行空间匹配滤波,以获得该符号周期的检测符号,并且将针对每个符号周期发送的每个数据符号获得的多个估计合并 STTD。

    Reduced complexity detection and decoding for a receiver in a communication system
    5.
    发明申请
    Reduced complexity detection and decoding for a receiver in a communication system 有权
    降低通信系统中接收机的复杂度检测和解码

    公开(公告)号:US20070116143A1

    公开(公告)日:2007-05-24

    申请号:US11345976

    申请日:2006-02-01

    IPC分类号: H04L23/02 H04L1/02 H03D1/00

    摘要: Techniques for performing detection and decoding at a receiver are described. In one scheme, the receiver obtains R received symbol streams for M data streams transmitted by a transmitter, performs receiver spatial processing on the received symbols to obtain detected symbols, performs log-likelihood ratio (LLR) computation independently for each of D best data streams, and performs LLR computation jointly for the M−D remaining data streams, where M>D≧1 and M>1. The D best data streams may be selected based on SNR and/or other criteria. In another scheme, the receiver performs LLR computation independently for each of the D best data streams, performs LLR computation jointly for the M−D remaining data streams, and reduces the number of hypotheses to consider for the joint LLR computation by performing a search for candidate hypotheses using list sphere detection, Markov chain Monte Carlo, or some other search technique.

    摘要翻译: 描述在接收机处执行检测和解码的技术。 在一种方案中,接收机获得用于由发射机发送的M个数据流的R个接收符号流,对接收到的符号执行接收机空间处理以获得检测符号,对于每个D个最佳数据流独立地执行对数似然比(LLR)计算 并且为MD剩余数据流共同执行LLR计算,其中M> D> = 1且M> 1。 可以基于SNR和/或其他标准来选择D个最佳数据流。 在另一方案中,接收机对于每个D最佳数据流独立地执行LLR计算,为MD剩余数据流共同执行LLR计算,并且通过执行候选假设的搜索来减少对于联合LLR计算考虑的假设的数量 使用列表球体检测,马尔科夫链蒙特卡罗或其他搜索技术。

    METHOD AND APPARATUS FOR ALLOCATING DOWNLINK RESOURCES IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM
    6.
    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
    7.
    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
    8.
    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。