公开(公告)号：US10021684B2

公开(公告)日：2018-07-10

申请号：US15676517

申请日：2017-08-14

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad ,  Yasaman Ghasempour ,  Mohammad Khojastepour ,  Sampath Rangarajan

IPC: H04B7/04 ,  H04W72/04 ,  H04B7/0452

CPC classification number: H04W72/042 ,  H04B7/0452 ,  H04L25/03343 ,  H04L25/03898

Abstract: A computer-implemented method is provided for downlink scheduling in a MU-MIMO telecommunication system. The method includes identifying for each of multiple virtual users which collectively form a ground set of virtual users, a respective transmit precoder and receive beamformer combination that maximizes a difference between two submodular set functions applied over the ground set of virtual users, from among a plurality of combinations formed from a respective one of a plurality of transmit precoders and a respective one of a plurality of receive beamformers. The method includes transmitting data from at least some multiple virtual users, based on a downlink transmission schedule determined from the respective transmit precoder and receive beamformer combination identified for the at least some multiple virtual users. The ground set is formed from respective combinations of multiple actual users and the plurality of receive beamformers. The functions correspond to an achievable virtual user transmission rate.

公开(公告)号：US10020859B2

公开(公告)日：2018-07-10

申请号：US14156064

申请日：2014-01-15

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad ,  Guosen Yue ,  Sampath Rangarajan

IPC: H04B7/06 ,  H04B7/0452 ,  H04B7/024 ,  H04L5/00

CPC classification number: H04B7/0632 ,  H04B7/024 ,  H04B7/0452 ,  H04B7/0617 ,  H04B7/0639 ,  H04L5/0048 ,  H04L5/0073

Abstract: A method implemented in a base station used in a wireless communications system where different antenna arrays are employed for transmissions to different co-scheduled users in a cell is disclosed. The method includes configuring multiple channel state information (CSI) processes for a user equipment (UE), and configuring, for the UE, a plurality of non-zero power (NZP) CSI reference signal (RS) resources, each of which is associated with an antenna array. Other apparatuses, systems, and methods also are disclosed.

公开(公告)号：US20180084532A1

公开(公告)日：2018-03-22

申请号：US15676517

申请日：2017-08-14

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad ,  Yasaman Ghasempour ,  Mohammad Khojastepour ,  Sampath Rangarajan

IPC: H04W72/04 ,  H04B7/0452

CPC classification number: H04W72/042 ,  H04B7/0452 ,  H04L25/03343

Abstract: A computer-implemented method is provided for downlink scheduling in a MU-MIMO telecommunication system. The method includes identifying for each of multiple virtual users which collectively form a ground set of virtual users, a respective transmit precoder and receive beamformer combination that maximizes a difference between two submodular set functions applied over the ground set of virtual users, from among a plurality of combinations formed from a respective one of a plurality of transmit precoders and a respective one of a plurality of receive beamformers. The method includes transmitting data from at least some multiple virtual users, based on a downlink transmission schedule determined from the respective transmit precoder and receive beamformer combination identified for the at least some multiple virtual users. The ground set is formed from respective combinations of multiple actual users and the plurality of receive beamformers. The functions correspond to an achievable virtual user transmission rate.

公开(公告)号：US09906340B2

公开(公告)日：2018-02-27

申请号：US15015333

申请日：2016-02-04

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad ,  Sampath Rangarajan ,  Yasushi Maruta ,  Duong Pham ,  Arun Gurung ,  Caroline Liang ,  Patricia Wells ,  Robert Arnott

IPC: H04W72/08 ,  H04W72/06 ,  H04L5/00 ,  H04W24/02 ,  H04W72/04 ,  H04B7/024 ,  H04B7/06 ,  H04W84/04 ,  H04W88/02 ,  H04W88/08

CPC classification number: H04L5/0035 ,  H04B7/024 ,  H04B7/0626 ,  H04L5/0057 ,  H04L5/006 ,  H04L5/0064 ,  H04W24/02 ,  H04W72/0406 ,  H04W72/06 ,  H04W72/082 ,  H04W72/085 ,  H04W84/042 ,  H04W88/02 ,  H04W88/08

Abstract: A method and transmitting device are provided for coordinated multi-point transmission scheduling by a transmitting device over one or more heterogeneous wireless networks that include a set of clusters. Each of the clusters has a set of transmission points for serving a set of user equipment devices. The method includes determining constraints imposed on any of the user equipment devices. The method further includes receiving channel state information feedback from the user equipment devices. The method also includes obtaining user weights and buffer sizes. The method additionally includes iteratively determining a weighted sum of user rates based on the constraints, the channel state information feedback, the user weights, and the buffer sizes. The iteratively determining step determines the weighted sum of user rates based on an initial weighted sum of user rates determined for the user equipment devices without the constraints.

公开(公告)号：US09847818B2

公开(公告)日：2017-12-19

申请号：US14295422

申请日：2014-06-04

Applicant: NEC Laboratories America, Inc.

Inventor： Guosen Yue ,  Narayan Prasad ,  Sampath Rangarajan

IPC: H04B7/04 ,  H04B7/0456 ,  H04B7/06 ,  H04L5/00

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.

公开(公告)号：US09148818B2

公开(公告)日：2015-09-29

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: H04W4/00 ,  H04W28/04 ,  H04B7/02 ,  H04B7/04 ,  H04L5/00

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。

公开(公告)号：US09130620B2

公开(公告)日：2015-09-08

申请号：US14083537

申请日：2013-11-19

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad

IPC: H04B7/04 ,  H04B7/02

CPC classification number: H04B7/0456 ,  H04B7/024 ,  H04B7/0465

Abstract: There is provided a method for generating transmit precoders for a communication system having a plurality of transmitters and a plurality of receivers forming a plurality of transmitter-receiver pairs. Each of the transmitters and receivers has a respective plurality of antennas. The method includes initializing the transmit precoders. The method further includes updating a plurality of receiver filters and a plurality of slack variables using closed form expressions. The method also includes updating the transmit precoders responsive to an output of said prior updating step. The method additionally includes iteratively repeating the updating steps until convergence is reached to obtain a final set of transmit precoders. The transmit precoders are updated to perform precoding for multiple stream data transmission for each of the plurality of transmitter-receiver pairs on each of a plurality of slots under a per-antenna power constraint imposed on each of the plurality of antennas.

Abstract translation: 提供了一种用于生成具有多个发射机的通信系统和形成多个发射机 - 接收机对的多个接收机的发射预编码器的方法。 每个发射机和接收机具有相应的多个天线。 该方法包括初始化发送预编码器。 该方法还包括使用闭合形式表达式更新多个接收器滤波器和多个松弛变量。 该方法还包括响应于所述先前更新步骤的输出更新发送预编码器。 该方法另外包括迭代地重复更新步骤，直到达到收敛以获得最终的发送预编码集合。 更新发射预编码器以在施加在多个天线中的每一个上的每天线功率约束下，在多个时隙中的每一个上对多个发射机 - 接收机对中的每一个执行多个流数据传输的预编码。

公开(公告)号：US09124319B2

公开(公告)日：2015-09-01

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: H04L27/34 ,  H04B7/04 ,  H04L25/03 ,  H04L27/00 ,  H04W72/12

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：US09094145B2

公开(公告)日：2015-07-28

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 ,  H04J11/00 ,  H04L5/00 ,  H04L1/00 ,  H04B7/04 ,  H04W24/10 ,  H04B7/02 ,  H04B7/06

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：US20150208256A1

公开(公告)日：2015-07-23

申请号：US14603723

申请日：2015-01-23

Applicant: NEC Laboratories America, Inc.

Inventor： Narayan Prasad ,  Mustafa Arslan ,  Sampath Rangarajan

IPC: H04W24/04 ,  H04L5/00 ,  H04W28/02 ,  H04W72/08

CPC classification number: H04W28/0236 ,  H04L5/0037 ,  H04L5/0058 ,  H04L5/0073 ,  H04L5/0076 ,  H04W24/02 ,  H04W72/1273

Abstract: We show that for any given muting fraction, a more constrained version of the problem of interest can be optimally solved in an efficient manner. In addition, the obtained solution is also a near-optimal solution for the original problem (for the given muting ratio). This allows us provide an algorithm that offers a good solution to the original problem with a tractable complexity. We also derive a lower complexity greedy that offers good performance and a certain worst-case performance guarantee. Simulations over an example LTE HetNet topology reveal the superior performance of the proposed algorithms and underscore the benefits of jointly exploiting partial muting of the macro and load balancing.

Abstract translation: 我们表明，对于任何给定的静噪分数，可以以有效的方式最佳地解决感兴趣问题的更受约束的版本。 此外，所获得的解决方案也是原始问题的近似最优解（对于给定的静噪比）。 这允许我们提供一种算法，为原来的问题提供一个很好的解决方案，容易复杂。 我们还推出了一个较低复杂性的贪心，提供了良好的性能和一些最坏的性能保证。 通过示例LTE HetNet拓扑的仿真揭示了所提出的算法的优越性能，并强调了共同利用宏和负载均衡的部分静音的好处。