Reallocation of excess power for full channel-state information (CSI) multiple-input, multiple-output (MIMO) systems

    公开(公告)号:US20060116155A1

    公开(公告)日:2006-06-01

    申请号:US11330733

    申请日:2006-01-11

    IPC分类号: H04B7/00 H04Q7/20

    摘要: Techniques to allocate the total transmit power to the transmission channels in a multi-channel communication system such that higher overall system spectral efficiency and/or other benefits may be achieved. The total transmit power may be initially allocated to the transmission channels based on a particular power allocation scheme (e.g., the water-filling scheme). The initial allocation may result in more power being allocated to some transmission channels than needed to achieve the required SNR (e.g., the SNR needed to achieve the maximum allowed data rate), which would then result in these transmission channels being operated in the saturation region. In such situations, the techniques reallocate the excess transmit power of transmission channels operated in the saturation region to other transmission channels operated below the saturation region. In this way, higher data rate may be achieved for the “poorer” transmission channels without sacrificing the performance of the “better” transmission channels.

    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.

    Reduced complexity detection and decoding for a receiver in a communication system
    3.
    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。

    Power control for partial channel-state information (CSI) multiple-input, multiple-output (MIMO) systems
    4.
    发明申请
    Power control for partial channel-state information (CSI) multiple-input, multiple-output (MIMO) systems 有权
    部分信道状态信息(CSI)多输入多输出(MIMO)系统的功率控制

    公开(公告)号:US20050130694A1

    公开(公告)日:2005-06-16

    申请号:US11049319

    申请日:2005-02-01

    摘要: Techniques for controlling the transmit power for a number of data streams in a wireless multi-channel (e.g., MIMO) communication system. In one method, a number of received symbol streams are initially processed in accordance with a particular (e.g., CCMI, CCMI-SC, MMSE, or MMSE-SC) receiver processing technique to provide a number of detected data streams. The post-detection SNRs of the detected data streams are estimated, and each SNR that exceeds a setpoint is identified. This setpoint may correspond to (1) the SNR needed to achieve the maximum allowed spectral efficiency or (2) the target SNR needed to achieve a specified spectral efficiency. A new (or adjusted) transmit power for each detected data stream associated with a post-detection SNR that exceeds the setpoint is determined and used for the data stream. Different power control schemes are provided for different classes of receiver processing techniques with different characteristics.

    摘要翻译: 用于在无线多信道(例如,MIMO)通信系统中控制多个数据流的发射功率的技术。 在一种方法中,根据特定(例如,CCMI,CCMI-SC,MMSE或MMSE-SC)接收机处理技术最初处理多个接收到的符号流,以提供多个检测到的数据流。 估计检测到的数据流的检测后SNR,并且识别超过设定点的每个SNR。 该设定点可以对应于(1)实现最大允许频谱效率所需的SNR或(2)实现特定频谱效率所需的目标SNR。 确定与用于超过设定点的检测后SNR相关联的每个检测到的数据流的新(或调整的)发射功率并将其用于数据流。 为不同类型的具有不同特性的接收机处理技术提供不同的功率控制方案。

    High speed media access control with legacy system interoperability
    6.
    发明申请
    High speed media access control with legacy system interoperability 有权
    具有传统系统互操作性的高速媒体访问控制

    公开(公告)号:US20050135318A1

    公开(公告)日:2005-06-23

    申请号:US10964330

    申请日:2004-10-13

    摘要: Techniques for MAC processing for efficient use of high throughput systems that is backward compatible with various types of legacy systems are disclosed. In one aspect a first signal is transmitted according to a legacy transmission format to reserve a portion of a shared medium, and communication according to a second transmission format transpires during the reserved portion. In another aspect, a communication device may contend for access on a legacy system, and then communicate according to a new class communication protocol with one or more remote communication devices during the access period. In another aspect, a device may request access to a shared medium according to a legacy protocol, and, upon grant of access, the device may communicate with or facilitate communication between one or more remote stations according to a new protocol.

    摘要翻译: 公开了用于有效利用与各种类型的遗留系统向后兼容的高吞吐量系统的MAC处理技术。 在一个方面,根据传统的传输格式传输第一信号以保留共享介质的一部分,并且在保留部分期间发送根据第二传输格式的通信。 在另一方面,通信设备可以竞争在遗留系统上进行访问,然后在访问周期期间根据新的类通信协议与一个或多个远程通信设备进行通信。 在另一方面,设备可以根据传统协议请求对共享介质的访问,并且在授权访问时,设备可以根据新协议与一个或多个远程站通信或促进一个或多个远程站之间的通信。

    Efficient computation for eigenvalue decomposition and singular value decomposition of matrices
    7.
    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。

    Iterative detection and decoding for a MIMO-OFDM system
    8.
    发明申请
    Iterative detection and decoding for a MIMO-OFDM system 审中-公开
    MIMO-OFDM系统的迭代检测和解码

    公开(公告)号:US20050157811A1

    公开(公告)日:2005-07-21

    申请号:US11081260

    申请日:2005-03-15

    摘要: Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs). Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and “dual-maxima” approximation.

    摘要翻译: 用于迭代地检测和解码在无线(例如,MIMO-OFDM)通信系统中发送的数据的技术。 迭代检测和解码通过在检测器和解码器之间迭代地传递软(多位)“先验”信息来执行。 检测器接收调制符号,执行与在发射机处执行的符号映射互补的检测功能,并为发送的编码比特提供软判决符号。 软判决符号中的“外在信息”然后由解码器解码以提供其外在信息,其包括检测器在检测过程中使用的先验信息。 可以重复检测和解码多次。 可以使用对数似然比(LLR)来表示软判决符号和先验信息。 提供技术以减少与导出LLR相关联的计算复杂度,包括干扰归零以隔离每个发射信号和“双最大值”近似。

    BROADCAST TRANSMISSION WITH SPATIAL SPREADING IN A MULTI-ANTENNA COMMUNICATION SYSTEM
    10.
    发明申请
    BROADCAST TRANSMISSION WITH SPATIAL SPREADING IN A MULTI-ANTENNA COMMUNICATION SYSTEM 有权
    在多天线通信系统中具有空间扩展的广播传输

    公开(公告)号:US20080031372A1

    公开(公告)日:2008-02-07

    申请号:US11870380

    申请日:2007-10-10

    IPC分类号: H04L27/28

    摘要: An access point in a multi-antenna system broadcasts data using spatial spreading to randomize an “effective” channel observed by each user terminal for each block of data symbols broadcast by the access point. At the access point, data is coded, interleaved, and modulated to obtain ND data symbol blocks to be broadcast in NM transmission spans, where ND≧1 and NM>1. The ND data symbol blocks are partitioned into NM data symbol subblocks, one subblock for each transmission span. A steering matrix is selected (e.g., in a deterministic or pseudo-random manner from among a set of L steering matrices) for each subblock. Each data symbol subblock is spatially processed with the steering matrix selected for that subblock to obtain transmit symbols, which are further processed and broadcast via NT transmit antennas and in one transmission span to user terminals within a broadcast coverage area.

    摘要翻译: 多天线系统中的接入点使用空间扩展广播数据,以随机化由接入点广播的每个数据符号块由每个用户终端观察到的“有效”信道。 在接入点,对数据进行编码,交织和调制,以获得要在N N个传输跨度中广播的N个D个数据符号块,其中N < / SUB >> = 1和N&lt; 1&gt; 1。 N N个数据符号块被划分为N个M个数据符号子块,每个传输跨度的一个子块。 对于每个子块,选择导向矩阵(例如,从一组L个导引矩阵中以确定性或伪随机方式)。 利用为该子块选择的导引矩阵来对每个数据符号子块进行空间处理,以获得发射符号,其进一步经由N T T个发射天线处理和广播,并且在一个传输跨度内广播覆盖范围内的用户终端 区。