公开(公告)号：US09450657B2

公开(公告)日：2016-09-20

申请号：US14465053

申请日：2014-08-21

Applicant: NEC Laboratories America, Inc.

Inventor： Guosen Yue ,  Narayan Prasad ,  Sampath Rangarajan ,  Samet Oymak

IPC: H04L1/06 ,  H04L5/00 ,  H04W72/04 ,  H04B7/04

CPC classification number: H04B7/0465 ,  H04B7/0439 ,  H04B7/0443 ,  H04B7/0452 ,  H04B7/0469 ,  H04B7/0617 ,  H04L5/0037 ,  H04W52/367 ,  H04W52/42

Abstract: A method and system are provided. The method includes providing transmit precoders for a multiple-input and multiple-output communication system having a plurality of transmit antennas. The plurality of transmit antennas are for forming, using precoding, a plurality of channels such that each of the plurality of channels are configurable to serve a respective one of a plurality of users. The providing step includes imposing a respective average transmit antenna power constraint on each of the plurality of transmit antennas. The providing step further includes determining a diagonal precoder responsive to applying column scaling to a downlink channel matrix having a plurality of rows and a plurality of columns. The providing step additionally includes generating, from the diagonal precoder, a weighted precoder in accordance with the respective average antenna power constraint by optimizing a weighted sum-rate obtained upon transmitting respective signals over the plurality of channels.

Abstract translation: 提供了一种方法和系统。 该方法包括为具有多个发射天线的多输入和多输出通信系统提供发射预编码器。 多个发射天线用于使用预编码形成多个信道，使得多个信道中的每一个可配置为服务于多个用户中的相应一个。 提供步骤包括在多个发射天线中的每一个上施加相应的平均发射天线功率约束。 所述提供步骤还包括：响应于对具有多个行和多个列的下行链路信道矩阵应用列缩放来确定对角预编码器。 提供步骤还包括从对角线预编码器根据相应的平均天线功率约束，通过优化通过多个信道发送各个信号而获得的加权和频率来生成加权预编码器。

公开(公告)号：US09071471B2

公开(公告)日：2015-06-30

申请号：US14214497

申请日：2014-03-14

Applicant: NEC Laboratories America, Inc.

Inventor： Guosen Yue ,  Sampath Rangarajan

IPC: H03K9/02 ,  H04L27/02

CPC classification number: H04L27/02 ,  H04L27/3405 ,  H04L27/38

Abstract: Disclosed are methods and structures for soft symbol and variance estimation for QAM constellations including a big-flipping framework and efficient methods for soft symbol estimation and variance estimation for QAM. Disclosed are efficient Gray mapping which provides a much lower complexity, i.e., log N for N-QAM for both squared and non-squared QAM constellations. Also disclosed is an approximation method that avoids multiplications completely while exhibiting only a slight performance degradation. Finally, a low complexity method for variance estimations, particularly second moment estimations for both squared and non-squared QAM constellations with Gray mapping are disclosed. Advantageously—using the disclosed methods—the complexity of the second moment estimation is reduced to O((log N)^2) for an N-QAM symbol for both squared and non-squared QAM.

Abstract translation: 公开了用于QAM星座的软符号和方差估计的方法和结构，包括大翻转框架和用于QAM的软符号估计和方差估计的有效方法。 公开的是高效的格雷映射，其提供了低得多的复杂度，即对于平方和非平方QAM星座的N-QAM的log N。 还公开了一种近似方法，其在仅显示轻微的性能降级的情况下完全避免乘法。 最后，公开了用于方差估计的低复杂度方法，特别是具有灰度映射的平方和非平方QAM星座的二次矩估计。 有利地，使用所公开的方法 - 对于平方和非平方QAM的N-QAM符号，第二时刻估计的复杂度被减小到O（（log N）2）。

公开(公告)号：US20140362784A1

公开(公告)日：2014-12-11

申请号：US14295422

申请日：2014-06-04

Applicant: NEC Laboratories America, Inc.

Inventor： Guosen Yue ,  Narayan Prasad ,  Sampath Rangarajan

IPC: H04L5/00 ,  H04W24/10 ,  H04B7/04

CPC classification number: H04B7/0478 ,  H04B7/0456 ,  H04B7/0486 ,  H04B7/0617 ,  H04B7/0626 ,  H04B7/063 ,  H04B7/0639 ,  H04B7/0658 ,  H04B7/066 ,  H04B7/0697 ,  H04L5/0023 ,  H04L5/0057

Abstract: A method implemented in a base station used in a wireless communications system is disclosed. The method comprises receiving, from a user equipment, rank indication (RI), a first precoding matrix indicator (PMI), and a second PMI (codebook index i2), wherein values 0-15 are assigned to the second PMI IPMI2 for RI=1 and values 0-3 are assigned to the second PMI IPMI2 for each of RI=2, RI=3, and RI=4, and wherein codebook index i2 comprises IPMI2 for RI=1. Other methods, apparatuses, and systems also are disclosed.

Abstract translation: 公开了一种在无线通信系统中使用的基站中实现的方法。 该方法包括从用户设备接收秩指示（RI），第一预编码矩阵指示符（PMI）和第二PMI（码本索引i2），其中值0-15被分配给第二PMI IPMI2用于RI = 1和值0-3被分配给RI = 2，RI = 3和RI = 4中的每一个的第二PMI IPMI2，并且其中码本索引i2包括RI = 1的IPMI2。 还公开了其它方法，装置和系统。

公开(公告)号：US20140044061A1

公开(公告)日：2014-02-13

申请号：US13948409

申请日：2013-07-23

Applicant: NEC Laboratories America, Inc.

Inventor： Guosen Yue ,  Narayan Prasad ,  Meilong Jiang ,  Sampath Rangarajan

IPC: H04W72/04

CPC classification number: H04J11/0053 ,  H04B7/024 ,  H04B7/0456 ,  H04B7/063 ,  H04B7/0632 ,  H04L1/0026 ,  H04L1/0068 ,  H04L1/0077 ,  H04L5/0035 ,  H04L5/0044 ,  H04L5/0048 ,  H04L5/005 ,  H04L5/0053 ,  H04L5/0057 ,  H04L5/0073 ,  H04L5/0091 ,  H04W24/10 ,  H04W72/042

Abstract: A communications method implemented in a transmission point (TP) used in a coordinated multipoint transmission and reception (CoMP) system is disclosed. The communications method comprises transmitting, to a user equipment (UE), attributers for up to four indicators indicating at least physical downlink shared channel (PDSCH) resource element (RE) mapping, and transmitting, to the UE, one of the four indicators, each of which is conveyed in 2 bits, wherein the four indicators comprises ‘00’, ‘01’, ‘10’, and ‘11’ corresponding to a first set, a second set, a third set, and a fourth set of parameters, respectively. Other methods, apparatuses, and systems are also disclosed.

Abstract translation: 公开了在协调多点发送和接收（CoMP）系统中使用的传输点（TP）中实现的通信方法。 所述通信方法包括：向用户设备（UE）发送最多指示至少物理下行链路共享信道（PDSCH）资源元素（RE）映射的四个指示符的属性，并向所述UE发送所述四个指示符之一， 其中每一个以2位传送，其中四个指示符包括对应于第一组，第二组，第三组和第四组参数的“00”，“01”，“10”和“11” ， 分别。 还公开了其它方法，装置和系统。

公开(公告)号：US09025692B2

公开(公告)日：2015-05-05

申请号：US14247643

申请日：2014-04-08

Applicant: NEC Laboratories America, Inc.

Inventor： Guosen Yue ,  Narayan Prasad ,  Meilong Jiang ,  Sampath Rangarajan

IPC: H04L27/00 ,  H04B7/04 ,  H04L25/03 ,  H04L1/18 ,  H04L1/06

CPC classification number: H04B7/0456 ,  H04L1/0618 ,  H04L1/1896 ,  H04L25/03343 ,  H04L2025/03426

Abstract: A method implemented in a user terminal is disclosed. The method comprises obtaining known precoding matrix P of rank r and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank r′, forming an approximate channel covariance matrix, estimating a minimum mean square error receiver SINR for each layer to be retransmitted responsive to said forming, and finding a retransmission precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ. Other methods, apparatuses, and systems also are disclosed.

Abstract translation: 公开了一种在用户终端中实现的方法。 该方法包括获得秩r的已知预编码矩阵P以及在原始传输中使用的调制和编码方案分配以及期望的重传秩r'，形成近似信道协方差矩阵，估计每层的最小均方误差接收机SINR 响应于所述形成重新发送，并从上一个码本中找到重新发送预编码矩阵，其使在上行链路多输入多输出MIMO混合自动重传请求HARQ中进行重新发送的预编码选择最大化的和速率。 还公开了其它方法，装置和系统。

公开(公告)号：US20150092556A1

公开(公告)日：2015-04-02

申请号：US14496190

申请日：2014-09-25

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad ,  Sampath Rangarajan ,  Guosen Yue ,  Yi Xu

IPC: H04B7/04 ,  H04W72/04 ,  H04W28/08 ,  H04L5/00

CPC classification number: H04B7/0452 ,  H04L5/0025 ,  H04L5/0035 ,  H04L5/0037 ,  H04L5/006 ,  H04L5/0062

Abstract: Methods are provided. A method includes determining respective weighted likelihoods corresponding to a plurality of users in a multiple-input multiple-output communication system. The method further includes forming a plurality of user groups from the plurality of users using an iterative K-means clustering technique applied to the plurality of users. The iterative K-means clustering technique is responsive to the respective weighted likelihoods.

Abstract translation: 提供方法。 一种方法包括确定在多输入多输出通信系统中对应于多个用户的各个加权似然度。 该方法还包括使用应用于多个用户的迭代K均值聚类技术从多个用户形成多个用户组。 迭代K均值聚类技术响应各自的加权似然度。

公开(公告)号：US20140341064A1

公开(公告)日：2014-11-20

申请号：US14449307

申请日：2014-08-01

Applicant: NEC Laboratories America, Inc.

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

IPC: H04W24/10 ,  H04B7/04

CPC classification number: H04W24/10 ,  H04B7/0417 ,  H04B7/0452 ,  H04B7/0469 ,  H04B7/0486 ,  H04B7/0626 ,  H04B7/063 ,  H04B7/065

Abstract: A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. The method includes transmitting to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule, and transmitting to the base station a second CSI report determined according to an MU-MIMO rule. Other methods, apparatuses, and systems also are disclosed.

Abstract translation: 公开了一种在配置成在多用户（MU）多输入多输出（MIMO）无线通信系统中使用的用户设备中实现的方法。 该方法包括向基站发送根据单用户（SU）MIMO规则确定的第一信道状态信息（CSI）报告，以及向基站发送根据MU-MIMO规则确定的第二CSI报告。 还公开了其它方法，装置和系统。

公开(公告)号：US20140233414A1

公开(公告)日：2014-08-21

申请号：US14248048

申请日：2014-04-08

Applicant: NEC Laboratories America, Inc.

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

IPC: H04W24/08

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

Abstract: A method for determining attributes of communication channels of multi-user (MU)-multiple input multiple output (MIMO) users in an orthogonal frequency division multiplexing based multiple access (OFDMA) system is disclosed. The method comprises 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 or 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, 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, and transmitting to the base station an indication of the one or more signal quality measures. Other methods, apparatuses, and systems also are disclosed.

Abstract translation: 公开了一种用于在基于正交频分复用的多址（OFDMA）系统中确定多用户（MU） - 多输入多输出（MIMO））用户的通信信道的属性的方法。 该方法包括从基站接收对于连续子载波的至少一个子带，在基站上共同调度的流的总数的估计或上限的指示 至少一个子带或基站处的发射功率的一小部分的指示，其被施加到被调度用于传输到特定用户的流，确定用于所述至少一个子带的一个或多个信号质量度量 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分数或估计或上限中的至少一个，并且向所述基站发送所述一个的所述一个 或更多的信号质量措施。 还公开了其它方法，装置和系统。

公开(公告)号：US20140226745A1

公开(公告)日：2014-08-14

申请号：US14258378

申请日：2014-04-22

Applicant: NEC Laboratories America, Inc.

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

IPC: H04B7/04 ,  H04L27/34

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

Abstract: A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed.

Abstract translation: 公开了一种在多用户多输入多输出（MU-MIMO）无线通信系统中使用的用户设备中实现的方法。 该方法包括从基站接收用户设备的第一调制类型的指示，接收用户设备的第一数据信号，为共同调度的用户设备接收第二数据信号，其中第二调制类型为 共同调度的用户设备对于用户设备是未知的，并且确定第二调制类型。 还公开了其它方法，系统和装置。

公开(公告)号：US20130229992A1

公开(公告)日：2013-09-05

申请号：US13749869

申请日：2013-01-25

Applicant: NEC LABORATORIES AMERICA, INC.

Inventor： Guosen Yue ,  Narayan Prasad ,  Meilong Jiang ,  Sampath Rangarajan

IPC: H04W28/04

CPC classification number: H04W28/044 ,  H04B7/024 ,  H04B7/0486 ,  H04L5/001 ,  H04L5/0035 ,  H04L5/0044 ,  H04L5/0051 ,  H04W74/085

Abstract: A method implemented in a mobile communications network supporting coordinated multiple point transmission and reception (CoMP) is disclosed. The method includes transmitting, to a user equipment (UE), data in a physical downlink shared channel (PDSCH), and transmitting a reference signal to the UE, wherein a union of resource elements (REs) allocated for reference signals transmitted from a subset of a plurality of transmission points (TPs) in a CoMP set are excluded from resource mapping for transmitting the data to the UE. Other methods, systems, and apparatuses also are disclosed.

Abstract translation: 公开了一种在支持协调多点发送和接收（CoMP）的移动通信网中实现的方法。 该方法包括向用户设备（UE）发送物理下行链路共享信道（PDSCH）中的数据，以及向UE发送参考信号，其中分配给用于从子集发送的参考信号的资源元素（RE）的并集 从用于向UE发送数据的资源映射中排除CoMP集合中的多个传输点（TP）。 还公开了其它方法，系统和装置。