Nec Laboratories America, Inc.

Nec Corporation

Future Wei Technologies, Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Other

Guosen Yue

Sampath Rangarajan

Narayan Prasad

Meilong Jiang

Mohammad Ali Khojastepour

Xiaodong Wang

Mohammad Madihian

Xiao-Feng Qi

Fu-Hsuan Chiu

Xiadong Wang

Yan Xin

Kai Li

Chen Gong

Momin A Uppal

Hongwei Kong

Xiaoxin Qiu

Honghai Zhang

Sungeun Lee

Mohammad A Khajehnejad

Xiao Feng Qi

Weng Chon Ao

Bohan Zhang

Sam Path Rangarajan

Li Zhang

Chuxiang Li

Yi Xu

Samet Oymak

A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed.

Codebook construction

A hybrid combination of analog RF beamforming and digital pre-coding is used to improve signal-to-noise ratio and mitigate interference as between an RF base station and a plurality of wireless receivers within a cell area of the base station. Feedback overhead for beamforming training may be reduced by using indices for identifying the preferred beams of each wireless receiver. Scheduling for channel training may be based on identifying non-colliding ones of the RF beams and assigning these to corresponding wireless receivers which can best use the assigned beams in shared transmission slots.

Multiuser MIMO for large antenna systems with hybrid beamforming

A device comprises a memory that stores instructions executed by one or more processors to obtain a plurality of received signals transmitted by a user equipment from a plurality of antenna elements in a cellular network. A plurality of received signals transmitted by a user equipment from a plurality of antenna elements in a cellular network are obtained, and a plurality of complex channel values are calculated in an angle domain for a horizontal arrival angle and a vertical arrival angle per a received ray in a plurality of received rays in response to the plurality of received signals. An expected value of the plurality of channel values are calculated to obtain a power value for the horizontal arrival angle and vertical arrival angle having a time delay per the received ray.

High dimensional (HiDi) radio environment characterization and representation

Receivers including estimation unit (EU) circuits and related processing techniques for wireless systems are provided. Efficient expressions for quadrature amplitude modulation (QAM) symbol mean and variance calculations are utilized with efficient expressions and implementations that are adaptive to different orders of QAM formats. An EU circuit includes a mean estimation unit (MEU) circuit and/or second moment estimation unit (SEU) circuit. Each estimation unit circuit is configured to receive a variable QAM normalization factor so that the circuit can be adapted to different QAM orders. Each MEU or SEU circuit can be configured for sequential and/or parallel processing. A pool including multiple MEU circuits and/or a pool including multiple SEU circuits is provided in one embodiment, with a control unit for configuring and reconfiguring the pools of circuits for mean and variance estimation for data streams of QAM symbols.

Hardware virtualization for mean and variance estimations of QAM symbols

A method for adaptive user equipment (UE) grouping and beamforming includes the assignment each of a plurality of user equipment (UE) devices into a respective UE group of a plurality of UE groups. Each UE group has at least one UE device. A UE device is reassigned from the respective UE group to which it was previously assigned to an updated UE group. An updated respective beamforming vector is generated for the updated UE group until the updated respective beamforming vector for each UE group produces a largest average UE rate for the updated UE group.

Adaptively grouped user equipment multicasting and beamforming

Provided are an apparatus and method for pre-coding data based on quantized channel state information and channel statistics. In use, channel statistics are collected. Further, one or more reference signals are sent to a wireless device via at least one channel. Thereafter, quantized channel state information is received that corresponds to the at least one channel, where the quantized channel state information is sent by the wireless device based on the one or more reference signals. Data is pre-coded based on the quantized channel state information and the channel statistics. Further, the pre-coded data is transmitted to the wireless device.

Apparatus and method for pre-coding data based on channel statistics

The disclosure relates to technology for iterative localization and channel estimation in a communication system. A radio network node detects user location information from user equipment in a geographic region, where the geographic region includes a location cluster having multiple location levels. A location signature profile is formed for each level based on the location signature of a corresponding location level in the cluster, and a filter is generated for each level based on the location signature. Upon application of the filter that matches the location level of the location user information, the channel is estimated and the user location information is updated based on the channel estimation. The process is repeated until the user location information converges with a preselected convergence value.

Channel estimation in large scale MIMO systems using iterative location based spatial filtering

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.

Channel feedback for vertical and full-dimensional beamforming

A device comprises a memory that stores instructions executed by one or more processors to obtain a plurality of received signals transmitted by a user equipment from a plurality of antenna elements in a cellular network. A plurality of complex channel values are calculated in an angle domain for a horizontal arrival angle and a vertical arrival angle per a received ray in a plurality of received rays in response to the plurality of received signals. A frequency-offset estimation is calculated and applied to the plurality of complex channel values. The plurality of offset complex channel values are transformed to a plurality of channel values in a time domain. A time-offset estimation is calculated and applied to the plurality of channel values. An expected value of the plurality of channel values is obtained to obtain a power angle delay profile for the geographical location of the user equipment.

Circuits for producing signals representative of mean and variance estimations for quadrature amplitude modulation (QAM) are provided where the circuits comprise: sequentially repeated first circuit modules and sequentially repeated second circuit modules configured for producing updates in the corresponding estimation iterations. In one embodiment, a closest negative integer power of 2 is used as a substitute multiplicand when multiplying together two or more outputs of hyperbolic function generating units where the substituted for output is less than one. Size and complexity of the corresponding multiplier can then be reduced.

Efficient methods and recursive/scalable circuit architectures for QAM symbol mean and variance estimations

Embodiments provide systems and methods for selecting almost-blank sub-frames (ABSs) in wireless networks. ABSs may be utilized as part of enhanced inter-cell interference cancellation (eICIC). In an embodiment, an ABS pattern is selected in a distributed fashion without use of a direct interface between neighboring base stations. Embodiments operate with a hybrid self-organizing network (SON) that includes a centralized self-organizing network (cSON) unit and a distributed self-organizing network (dSON) unit. The cSON may provide the dSON with information about a plurality of ABS patterns, and the dSON may utilize the information received from the cSON to select an ABS pattern from the plurality of ABS patterns. In some embodiments, a base station may select neighboring base stations to perform eICIC based on a reference signal received power (RSRP).

Methods and systems for almost blank subframe (ABS) pattern selection for small cells

In some aspects, the disclosure is directed to methods and systems for intelligent transmit power management. Output power levels may be dynamically determined responsive to REM measurements, user equipment (UE) signal reports, information received from other cells (e.g. via X2 application protocol (X2AP) or other such communication protocols), or any combination of these or other information in an iterative level conditioning and limit checking process.

Transmit power management design and implementation

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 i), wherein values 0-15 are assigned to the second PMI Ifor RI=1 and values 0-3 are assigned to the second PMI Ifor each of RI=2, RI=3, and RI=4, and wherein codebook index icomprises Ifor RI=1. Other methods, apparatuses, and systems also are disclosed.

Channel state information (CSI) feedback and subsampling

Methods relating to managing operations of small cells are provided. One method includes receiving, from a management system configured to manage one or more operations of a plurality of small cells, a plurality of fractional frequency reuse (FFR) patterns for a frequency range. Each FFR pattern is configured to define a plurality of cell groupings, each including one or more of the plurality small cells. Each of the plurality of cell groupings is configured to transmit downlink transmissions over a different one of a plurality of frequency bands within the frequency range. The method further includes selecting a first FFR pattern from among the plurality of FFR patterns received from the management system and transmitting downlink transmissions in accordance with the first FFR pattern.

Growing community of inventors

Plainsboro, NJ, United States of America

Guosen Yue