公开(公告)号：US20110305299A1

公开(公告)日：2011-12-15

申请号：US13213510

申请日：2011-08-19

Applicant: Narayan Prasad ,  Mohammad Amir Khojastepour ,  Sampath Rangarajan

Inventor： Narayan Prasad ,  Mohammad Amir Khojastepour ,  Sampath Rangarajan

IPC: H04L25/49

CPC classification number: H04B7/0417 ,  H04B7/0469 ,  H04B7/0486 ,  H04B7/0632 ,  H04B7/0639 ,  H04B7/0669

Abstract: A precoding scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the multi antenna transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices that includes matrices having a structure matched to that of the eigenvectors of the spatial covariance matrix, wherein the spatial covariance matrix is modeled as a Hermitian and Toeplitz matrix parameterized by a single complex-valued scalar.

Abstract translation: 相应地确定其中估计下行链路信道并由多天线发射机使用的最佳预编码矩阵的预编码方案。 从包括具有与空间协方差矩阵的特征向量的结构匹配的矩阵的矩阵的码本中选择最佳预编码矩阵，其中空间协方差矩阵被建模为由单个复值标量参数化的Hermitian和Toeplitz矩阵 。

公开(公告)号：US20110255582A1

公开(公告)日：2011-10-20

申请号：US13088955

申请日：2011-04-18

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

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

IPC: H04B7/02 ,  H04B17/00

CPC classification number: H04B7/0452 ,  H04J11/0046 ,  H04L5/0023 ,  H04L25/03331 ,  H04L27/0008 ,  H04L27/0012 ,  H04L27/34 ,  H04W72/042 ,  H04W72/12

Abstract: Systems, methods and apparatuses for jointly demodulating data signals are disclosed. In accordance with the method, pilot signals are received from a base station and are processed. In addition, from a set of expected co-scheduled data streams, a subset of the co-scheduled data streams that are actually transmitted by the base station are determined based on the pilot signals. Further, a group of the transmitted co-scheduled data streams are selected from the determined subset. The data signals are received and jointly demodulated by employing the selected group of co-scheduled data streams and by suppressing non-selected data streams from the determined subset.

Abstract translation: 公开了用于联合解调数据信号的系统，方法和装置。 根据该方法，从基站接收导频信号并进行处理。 另外，从一组期望的共同调度数据流中，基于导频信号确定由基站实际发送的协同调度数据流的子集。 此外，从确定的子集中选择一组发送的协调调度数据流。 通过采用所选择的协同调度数据流组并通过从所确定的子集抑制未选择的数据流来接收和联合地解调数据信号。

公开(公告)号：US20110243018A1

公开(公告)日：2011-10-06

申请号：US13080403

申请日：2011-04-05

Applicant: NARAYAN PRASAD ,  Guosen Yue ,  Mohammad A. Khojastepour ,  Meilong Jiang ,  Sampath Rangarajan

Inventor： NARAYAN PRASAD ,  Guosen Yue ,  Mohammad A. Khojastepour ,  Meilong Jiang ,  Sampath Rangarajan

IPC: H04L12/26

CPC classification number: H04W24/08 ,  H04B7/0452 ,  H04B7/0465 ,  H04B7/0486 ,  H04W52/346 ,  H04W72/0406 ,  H04W72/085

Abstract: 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 and an indication of a fraction of a transmit power at the base station that is applied to streams that are scheduled for transmission to a particular user. The method further includes determining one or more signal quality measures for the at least one sub-band based on at least one of the fraction or 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 addition, an indication of the one or more signal quality measures is transmitted to the base station in the method.

Abstract translation: 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 至少一个子带和在基站处的发送功率的一小部分的指示，其被应用于被调度用于传输到特定用户的流。 该方法还包括基于由基站对其进行调度的流的总数的分数或估计或上限中的至少一个来确定至少一个子带的一个或多个信号质量度量 该至少一个子带。 此外，在该方法中向基站发送一个或多个信号质量测量的指示。

公开(公告)号：US07924933B2

公开(公告)日：2011-04-12

申请号：US11857273

申请日：2007-09-18

Applicant: Narayan Prasad ,  Xiaodong Wang ,  Mohammad Madihian

Inventor： Narayan Prasad ,  Xiaodong Wang ,  Mohammad Madihian

IPC: H04L1/02

CPC classification number: H04L1/20 ,  H04L1/208 ,  H04L25/03305 ,  H04L25/03318 ,  H04L25/03993

Abstract: A method includes the steps of: i) listing out all possibilities for first symbol of a two stream signal; ii) determining a second symbol of the two stream signal for each said first symbol listed out, iii) evaluating a metric for each said first symbol and second symbol pair, iv) determining the exact maximum log likelihood ratio for all bits associated with said first symbol using said metrics, v) decoding a codeword-1 using the maximum log likelihood ratios, vi) re-encoding said codeword-1, vii) modulating said re-encoded codeword-1, viii) subtracting said modulated re-encoded codeword-1 from said two stream signal, ix) determining metrics for all possibilities for second symbol in the signal obtained in viii, x) determining the maximum log likelihood ratios for all bits associated with second symbol, and xi) decoding said codeword-2 using the maximum log likelihood ratios for all bits associated with said second symbol.

Abstract translation: 一种方法包括以下步骤：i）列出双流信号的第一符号的所有可能性; ii）为列出的每个所述第一符号确定两个流信号的第二符号，iii）评估每个所述第一符号和第二符号对的度量，iv）确定与所述第一符号和第二符号对相关联的所有位的精确最大对数似然比 符号，使用所述度量，v）使用最大对数似然比对码字-1进行解码，vi）重新编码所述码字-1，vii）调制所述重新编码的码字-1，viii）减去所述经调制的重编码码字 - 1）从所述两个流信号中ix确定在viii中获得的信号中的第二符号的所有可能性的度量，x）确定与第二符号相关联的所有比特的最大对数似然比，以及xi）使用 与所述第二符号相关联的所有位的最大对数似然比。

公开(公告)号：US07852802B2

公开(公告)日：2010-12-14

申请号：US11554957

申请日：2006-10-31

Applicant: Narayan Prasad ,  Xiaodong Wang ,  Mohammad Madihian

Inventor： Narayan Prasad ,  Xiaodong Wang ,  Mohammad Madihian

IPC: H04W4/00

CPC classification number: H04B7/0697

Abstract: A joint scheduling and grouping technique provides uplink throughput maximization for space-division multiple access (SDMA) systems under proportional fairness constraints. In a slow-fading narrowband MIMO multiple access channel (MAC) multiple users, each equipped with multiple transmit antennas, communicate to a receiver equipped with multiple receive antennas. The users are unaware of the channel state information (CSI) whereas the receiver has perfect CSI and employs a successive group decoder (SGD). For an open-loop system, an optimum successive group decoder (OSGD) simultaneously minimizes the common outage probability and the individual outage probability of each user, over all SGDs of permissible decoding complexity. For each channel realization, the OSGD maximizes the error exponent of the decodable set of users. An adaptive SGD retains the outage optimality of the OSGD and minimizes decoding complexity. The SGD yields symmetric capacity gains commensurate with the decoding complexity allowed. The OSGD offers significantly improved performance at low decoding complexity.

Abstract translation: 联合调度和分组技术在比例公平约束下为空分多址（SDMA）系统提供上行吞吐量最大化。 在具有多个发射天线的慢衰落窄带MIMO多址信道（MAC）多用户中，与配备有多个接收天线的接收机通信。 用户不知道信道状态信息（CSI），而接收机具有完美的CSI并采用连续的组解码器（SGD）。 对于开环系统，最佳连续组解码器（OSGD）同时将所有SGD的常用中断概率和每个用户的单独中断概率最小化，从而允许解码复杂度。 对于每个通道实现，OSGD使可解码的用户组的错误指数最大化。 自适应SGD保留OSGD的中断最优性，并最大限度地降低解码复杂度。 SGD产生与允许的解码复杂度相称的对称容量增益。 OSGD在低解码复杂度下提供显着改进的性能。

公开(公告)号：US20100091729A1

公开(公告)日：2010-04-15

申请号：US12549546

申请日：2009-08-28

Applicant: Kai Yang ,  Narayan Prasad ,  Xiaodong Wang

Inventor： Kai Yang ,  Narayan Prasad ,  Xiaodong Wang

IPC: H04W72/04 ,  H04L27/28

CPC classification number: H04W72/0453 ,  H04L5/0007 ,  H04L5/0039 ,  H04L5/0044 ,  H04L5/0071 ,  H04L5/0076

Abstract: Systems and methods are disclosed to allocate resources in discrete Fourier transform spread orthogonal frequency division multiple access (DFT-S-OFDMA) networks, which involve determining a reward for each user when assigned a frequency chunk (FC) of subcarriers, where each FC is a set of contiguous subcarriers; splitting each user into one or more sub-users, with each sub-user having identical rewards; and assigning resources with a message-passing based FC allocation.

Abstract translation: 公开了系统和方法来分配离散傅立叶变换扩展正交频分多址（DFT-S-OFDMA）网络中的资源，这些网络涉及当分配子载波的频率块（FC）时确定每个用户的奖励，其中每个FC 一组连续的副载波; 将每个用户分成一个或多个子用户，每个子用户具有相同的奖励; 并使用基于消息传递的FC分配来分配资源。

公开(公告)号：US20090323619A1

公开(公告)日：2009-12-31

申请号：US12493044

申请日：2009-06-26

Applicant: Ali Tajer ,  Narayan Prasad ,  Xiaodong Wang

Inventor： Ali Tajer ,  Narayan Prasad ,  Xiaodong Wang

IPC: H04W72/00

CPC classification number: H04W72/08 ,  H04W16/14 ,  H04W16/28

Abstract: Systems and methods are disclosed for designing beamforming vectors for and allocating transmission rates to secondary users in a wireless cognitive network with secondary (cognitive) users and primary (license-holding) users by performing distributed beamforming design and rate allocation for the secondary users to maximize a minimum weighted secondary rate; and granting simultaneous spectrum access to the primary and secondary users subject to one or more co-existence constraints.

Abstract translation: 公开了系统和方法，用于通过对次要用户执行分布式波束成形设计和速率分配来设计用于辅助（认知）用户和主（许可证持有）用户的无线认知网络中的次级用户的波束成形向量并分配传输速率，以使次要用户最大化 最低加权次要率; 并允许同时进行频谱接入到受到一个或多个共存限制的主要和次要用户。

公开(公告)号：US20090276679A1

公开(公告)日：2009-11-05

申请号：US12435249

申请日：2009-05-04

Applicant: Narayan Prasad ,  Xiaodong Wang

Inventor： Narayan Prasad ,  Xiaodong Wang

IPC: H03M13/00

CPC classification number: H04L1/1845 ,  H03M13/09 ,  H03M13/6306 ,  H03M13/6337

Abstract: A method for decoding of multiple wireless signals by a chase combining hybrid-automatic-repeat-request CC-HARQ receiver includes demodulating wireless signals received from respective mobile sources using an effective channel matrix and decision statistics; updating log-likelihood-ratios LLRs and decoding the received codewords using the corresponding updated LLRs; determining set of correctly decoded codewords using a cyclic redundancy check; updating the effective channel matrix and decision statistics responsive to the step of determining; and resetting the effective channel matrix and decision statistics in the event that the number of decoding errors for a codeword exceeds its maximum limit after storing the updated LLRs of all remaining erroneously decoded codewords for which the number of decoding errors is below the respective maximum limit.

Abstract translation: 通过追踪组合混合自动重复请求CC-HARQ接收机对多个无线信号进行解码的方法包括使用有效信道矩阵和判定统计解调从相应移动源接收的无线信号; 更新对数似然比LLR并使用相应的更新的LLR对接收的码字进行解码; 使用循环冗余校验来确定正确解码的码字集合; 响应于确定步骤更新有效信道矩阵和决策统计; 并且在存储解码错误数量低于相应最大限制的所有剩余的错误解码的码字的更新的LLR之后，在码字的解码错误的数量超过其最大限制的情况下重置有效信道矩阵和判定统计。

公开(公告)号：US20080298486A1

公开(公告)日：2008-12-04

申请号：US12048440

申请日：2008-03-14

Applicant: LUCA VENTURINO ,  NARAYAN PRASAD ,  XIAODONG WANG ,  MOHAMMAD MADIHIAN

Inventor： LUCA VENTURINO ,  NARAYAN PRASAD ,  XIAODONG WANG ,  MOHAMMAD MADIHIAN

IPC: H04L27/28

CPC classification number: H04L27/2601 ,  H04L5/0007 ,  H04L5/003 ,  H04L5/0032 ,  H04L5/0037 ,  H04L5/0042 ,  H04L5/0044 ,  H04L5/0058 ,  H04L5/006 ,  H04L5/0066 ,  H04W16/10

Abstract: A multi-cell Orthogonal Frequency-Division Multiple Access (OFDMA) based wireless system and method with full spectral reuse co-channel interference mitigation via base station coordination in a downlink channel includes a plurality of base stations configured to handle communications with mobile units. A central controller is configured to mitigate interference between base stations via jointly optimizing coordinated scheduling and power allocation in accordance with a sub-optimal iterative solution. Five methods provide the solution, which include: 1) Improved Iterative Water-Filling (I-IWF); 2) Iterative Spectrum Balancing (ISB); 3) Successive Convex Approximation for Low-complexity (SCALE); 4) Opportunistic Base Station Selection (OBSS) and 5) Per-tone binary power control (PT-BPC).

Abstract translation: 一种基于多小区正交频分多址接入（OFDMA）的无线系统和方法，具有通过基站协调在下行链路信道中进行全频谱复用同信道干扰减轻的方法，包括：被配置为处理与移动单元的通信的多个基站。 中央控制器被配置为通过根据次优迭代解联合优化协调调度和功率分配来减轻基站之间的干扰。 五种方法提供了解决方案，其中包括：1）改进的迭代灌水（I-IWF）; 2）迭代频谱平衡（ISB）; 3）低复杂度（SCALE）的连续凸近似; 4）机会基站选择（OBSS）和5）全音调二进制功率控制（PT-BPC）。

公开(公告)号：US20080225974A1

公开(公告)日：2008-09-18

申请号：US11857269

申请日：2007-09-18

Applicant: Narayan Prasad ,  Xiaodong Wang ,  Mohammad Madihian

Inventor： Narayan Prasad ,  Xiaodong Wang ,  Mohammad Madihian

IPC: H04L23/02

CPC classification number: H04L1/0054 ,  H04L25/03203 ,  H04L25/03286 ,  H04L25/03305

Abstract: A method includes the steps of i) listing out all possibilities for a first symbol of a two stream signal; ii) determining a second symbol of the two stream signal for each of the first symbol listed out, iii) evaluating a metric for each of the first symbol and second symbol pair, iv) listing out all possibilities for second symbol, v) determining a first symbol for each choice of the second symbol listed out, vi) evaluating a metric for each of the second symbol and first symbol pair, vii) determining an exact maximum log likelihood ratio for all bits using the metrics, and viii) decoding codeword(s) in the two stream signal using the determined exact maximum log likelihood ratio for all bits.

Abstract translation: 一种方法包括以下步骤：i）列出两个流信号的第一符号的所有可能性; ii）确定所列出的第一符号中的每一个的两个流信号的第二符号，iii）评估第一符号和第二符号对中的每一个的度量，iv）列出第二符号的所有可能性，v）确定 vi）对所述第二符号和第一符号对中的每个符号对的每一个的度量进行评估，vii）使用所述度量确定所有比特的精确最大对数似然比，以及viii）解码码字（ s）在两个流信号中，使用所确定的所有比特的精确最大对数似然比。