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    Multiple stage hybrid spectrum sensing methods and systems for cognitive radio
    5.
    发明授权
    Multiple stage hybrid spectrum sensing methods and systems for cognitive radio 有权
    用于认知无线电的多级混合频谱感测方法和系统

    公开(公告)号：US08761677B2

    公开(公告)日：2014-06-24

    申请号：US13408175

    申请日：2012-02-29

    申请人： Kyungtae Kim ,  Yan Xin ,  Sampath Rangarajan

    发明人： Kyungtae Kim ,  Yan Xin ,  Sampath Rangarajan

    IPC分类号： H04B15/00 ,  H04B17/00

    CPC分类号： H04W16/14 ,  H04L27/0006 ,  H04W72/1226

    摘要： Systems and methods for detecting unused channels in a cognitive radio system are described. In one method, data is communicated on a particular channel for a secondary receiver. In addition, a set of channels is iteratively scanned by collecting samples for each channel and for each iteration of the scanning. Here, iterations of the scanning progressively removes channels from the set of channels based on the collected samples and updates states of the channels in the set based on the collected samples to obtain a set of candidate channels. In response to detecting a pre-determined condition, communications on the particular channel are precluded and at least one of the candidate channels is evaluated by collecting additional samples on each of the channels. Further, at least one of the candidate channels is selected based on the evaluation for utilization by the one or more secondary receivers for data communication.

    摘要翻译： 描述了用于在认知无线电系统中检测未使用信道的系统和方法。 在一种方法中，数据在用于辅助接收机的特定信道上传送。 此外，通过收集每个通道的样本和扫描的每次迭代，迭代地扫描一组通道。 这里，扫描的迭代基于收集的采样逐渐地从信道集合中去除信道，并且基于收集的样本更新集合中的信道的状态以获得一组候选信道。 响应于检测到预定条件，排除特定信道上的通信，并且通过在每个信道上收集附加样本来评估候选信道中的至少一个。 此外，基于用于数据通信的一个或多个次要接收机的利用的评估来选择至少一个候选信道。

    MU-MIMO-OFDMA multi-rank CQI and precoder signaling schemes
    7.
    发明授权
    MU-MIMO-OFDMA multi-rank CQI and precoder signaling schemes 有权
    MU-MIMO-OFDMA多级CQI和预编码器信令方案

    公开(公告)号：US08705392B2

    公开(公告)日：2014-04-22

    申请号：US13080416

    申请日：2011-04-05

    申请人： Narayan Prasad ,  Guosen Yue ,  Mohammad A. Khojastepour ,  Meilong Jiang ,  Sampath Rangarajan

    发明人： Narayan Prasad ,  Guosen Yue ,  Mohammad A. Khojastepour ,  Meilong Jiang ,  Sampath Rangarajan

    IPC分类号： H04L12/26 ,  H04W4/00 ,  H04B7/02

    CPC分类号： H04W24/08 ,  H04B7/0452 ,  H04B7/0465 ,  H04B7/0486 ,  H04W52/346 ,  H04W72/0406 ,  H04W72/085

    摘要： Methods and systems for determining attributes of communication channels of MU-MIMO users in an (OFDMA) system are disclosed. One method includes receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band. The method further includes determining one or more signal quality measures for the at least one sub-band based on the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band in accordance with at least one of single-user scheduling rules or multi-user scheduling rules. In addition, the method includes transmitting to the base station an indication of the one or more signal quality measures and at least one tag identifying each signal quality measure as being determined in accordance with the single-user scheduling rules or the multi-user scheduling rules.

    摘要翻译： 公开了一种用于确定（OFDMA）系统中MU-MIMO用户的通信信道属性的方法和系统。 一种方法包括从基站接收对于连续子载波的至少一个子带，对由基站在...上共同调度的流的总数的估计或上限的指示 至少一个子带。 所述方法还包括基于由所述基站在所述至少一个子带上调度的流的总数的估计或所述上限来确定所述至少一个子带的一个或多个信号质量度量 根据单用户调度规则或多用户调度规则中的至少一个。 此外，该方法包括向基站发送一个或多个信号质量测量的指示，以及标识每个信号质量测量的至少一个标签，根据单用户调度规则或多用户调度规则确定 。

    Beamforming systems and methods for link layer multicasting
    9.
    发明授权
    Beamforming systems and methods for link layer multicasting 有权
    波束成形系统和链路层组播方法

    公开(公告)号：US08615047B2

    公开(公告)日：2013-12-24

    申请号：US13194132

    申请日：2011-07-29

    申请人： Mohammad A. Khojastepour ,  Sampath Rangarajan

    发明人： Mohammad A. Khojastepour ,  Sampath Rangarajan

    IPC分类号： H04L27/00

    CPC分类号： H04B7/0617 ,  H04B7/0626 ,  H04B7/0632

    摘要： Beamforming systems and methods are disclosed. In accordance with one method, an optimization problem that is based on channel matrices for a plurality of receivers is solved to obtain corresponding multipliers for each of the channel matrices. In addition, a determination of whether a maximum eigenvalue of a particular matrix that is based on the channel matrices and the multipliers has a multiplicity of one is made. Further, the method includes applying an eigenvector of the particular matrix for the maximum eigenvalue as a beamforming matrix to data symbols if the maximum eigenvalue has a multiplicity of one. Moreover, data signals are transmitted to the receivers in accordance with the beamforming matrix.

    摘要翻译： 公开了波束形成系统和方法。 根据一种方法，解决了基于多个接收机的信道矩阵的优化问题，以获得每个信道矩阵的相应乘法器。 此外，确定基于信道矩阵和乘法器的特定矩阵的最大特征值是否具有多重性。 此外，该方法包括将最大特征值的特定矩阵的特征向量作为波束成形矩阵应用于数据符号，如果最大特征值具有多个1。 此外，根据波束形成矩阵将数据信号发送到接收机。

    Reverse indexing methods and systems
    10.
    发明授权
    Reverse indexing methods and systems 有权
    反向索引方法和系统

    公开(公告)号：US08594248B2

    公开(公告)日：2013-11-26

    申请号：US12940761

    申请日：2010-11-05

    申请人： Mohammad A. Khojastepour ,  Sampath Rangarajan

    发明人： Mohammad A. Khojastepour ,  Sampath Rangarajan

    IPC分类号： H04L27/06

    CPC分类号： H04L27/28 ,  H04L5/0051 ,  H04L5/0053 ,  H04L5/0094 ,  H04L27/30

    摘要： Methods and systems for reversing indexing signal option selections are disclosed. The signal options can be any of a variety of options that permit the establishment of a communication link, including modulation format, coding rate, precoding index and assigned subbands. The selected options can be represented as a vector and the index can be determined by employing a worth function for a particular selected vector element that is dependent on a selection occurrence count of the element and on an element position count of the element. In particular, the index can be the summation of worth function values for each selected element.

    摘要翻译： 公开了用于反转索引信号选项选择的方法和系统。 信号选项可以是允许建立通信链路的各种选项中的任一种，包括调制格式，编码率，预编码索引和分配的子带。 所选择的选项可以被表示为向量，并且可以通过对依赖于元素的选择发生次数和元素的元素位置计数的特定选定向量元素采用值函数来确定索引。 特别地，索引可以是每个选定元素的值函数值的总和。