公开(公告)号：US20240284291A1

公开(公告)日：2024-08-22

申请号：US18290477

申请日：2021-10-15

Applicant: NEC Corporation

Inventor： Kazushi MURAOKA ,  Toshiki TAKEUCHI ,  Yasushi MARUTA

IPC: H04W36/32 ,  H04W64/00

CPC classification number: H04W36/324 ,  H04W36/322 ,  H04W64/003

Abstract: In order to control radio communication with a terminal apparatus in accordance with a movement situation of the terminal apparatus, a radio control apparatus is configured to estimate a location of the terminal apparatus, estimate a type of the terminal apparatus, predict movement of the terminal apparatus based on the estimated location, predict a future location of the terminal apparatus, estimate, based on the estimated type, a reception level of a radio signal at the future location for each communication parameter, and determine the communication parameter to be used for the terminal apparatus at the future location, based on an estimation result of the reception level.

公开(公告)号：US20230075680A1

公开(公告)日：2023-03-09

申请号：US17899086

申请日：2022-08-30

Applicant: NEC CORPORATION ,  OSAKA UNIVERSITY ,  THE DOSHISHA

Inventor： Takanobu DOI ,  Kazushi MURAOKA ,  Naoto ISHII ,  Takumi TAKAHASHI ,  Shinsuke IBI

IPC: H04B7/08

Abstract: A wireless receiving apparatus generates an N′×B′ weight matrix W whose columns are orthogonal to each other by decomposing an estimated N′×M′ channel matrix into the N′×B′ weight matrix W and a B′×M′ matrix containing two or more non-zero matrix elements in each column, where B′ is an integer less than or equal to N′-1 and greater than or equal to M′. Alternatively, the wireless receiving apparatus generates a combination of an N′×B′ sub-weight matrix W1 and at least one second sub-weight matrix, where the product of the sub-weight matrix W1 with the at least one second sub-weight matrix is equal to the weight matrix W. The wireless receiving apparatus performs receive beamforming on received signals of N′ receiving antennas using the weight matrix W or the sub-weight matrix W1. The wireless receiving apparatus then performs a BP algorithm using receive-beamformed signals.

公开(公告)号：US20210021446A1

公开(公告)日：2021-01-21

申请号：US17043308

申请日：2019-01-30

Applicant: NEC CORPORATION

Inventor： Jun SHIKIDA ,  Kazushi MURAOKA ,  Naoto ISHII

IPC: H04L25/02 ,  H04L27/26

Abstract: A radio apparatus (10) includes an estimation unit (2) configured to calculate an estimated value of a channel response for each of a plurality of antennas, a padding unit (3) configured to generate a first antenna-space channel vector having dimensions larger than the number of the antennas by combining the estimated value with a padding value, a spatial transformation unit (4) configured to calculate a first beam-space channel vector by spatial transforming the first antenna-space channel vector, a noise suppression unit (5) configured to generate a second beam-space channel vector by suppressing at least one element of the first beam-space channel vector, an inverse spatial transformation unit (6) configured to calculate a second antenna-space channel vector by inversely and spatial transforming the second beam-space channel vector, and an extraction unit (7) configured to determine an estimated value of each channel based on the second antenna-space channel vector.

公开(公告)号：US20190356400A1

公开(公告)日：2019-11-21

申请号：US16472935

申请日：2017-08-16

Applicant: NEC Corporation

Inventor： Kazushi MURAOKA

IPC: H04B17/318 ,  H04W8/00 ,  H04W52/36

Abstract: A wireless terminal (1) includes at least one memory (706), at least one processor coupled to the at least one memory (706); and an RF transceiver (701) capable of performing device-to-device (D2D) communication. The wireless terminal (1) receives a discovery signal transmitted from another wireless terminal (1) by using the RF transceiver (701), estimates a transmission power value of a transmission terminal of the discovery signal in accordance with a type of the discovery signal, and determines an inter-terminal path loss between the wireless terminals by using the estimated transmission power value and the received power value of the discovery signal. In this way, the inter-terminal path loss is estimated without the need for receiving notification regarding a transmission power value from a base station (2) to the terminal (1) when ProSe direct discovery is used.

公开(公告)号：US20180176759A1

公开(公告)日：2018-06-21

申请号：US15736057

申请日：2016-03-31

Applicant: NEC Corporation

Inventor： Kazushi MURAOKA

IPC: H04W8/00 ,  H04W72/04

CPC classification number: H04W8/005 ,  H04L5/0007 ,  H04L5/005 ,  H04W72/044 ,  H04W92/18

Abstract: A radio terminal (1) selects, from a resource pool in a discovery period, NTX subframes for NTX times of transmission of a discovery signal in the discovery period based on a first value n1 of a resource value autonomously selected by the radio terminal (1) or a first value n1 of a parameter received from a base station (2). The NTX subframes selected based on the value n1 are selected so as to share at least one common subframe with NTX subframes selected based on a second value, different from the first value n1, and so as to include at least one subframe different from any of the NTX subframes selected based on the second value. It is thus, for example, possible to attenuate decline in reception quality of a discovery signal due to interference resulting from In-Band Emissions (IBE) when direct discovery of D2D communication is performed.

公开(公告)号：US20160165535A1

公开(公告)日：2016-06-09

申请号：US15041767

申请日：2016-02-11

Applicant: NEC CORPORATION

Inventor： Toshifumi NAKAMURA ,  Kojiro HAMABE ,  Masayuki ARIYOSHI ,  Kazushi MURAOKA

IPC: H04W52/02 ,  H04W24/02

CPC classification number: H04W52/0206 ,  H04W24/02 ,  H04W28/0289 ,  H04W52/0203 ,  H04W52/0274 ,  H04W52/04 ,  H04W52/325 ,  H04W72/0406 ,  H04W88/08 ,  Y02D70/00 ,  Y02D70/164

Abstract: Because it is not possible to sufficiently reduce the number base stations that start uselessly in spite of being in a low traffic state, it is not possible to lower interference between adjacent cells and power consumption sufficiently. A base station starts transmission of a control signal with predetermined power when communication between another base station and a mobile station is started and a first predetermined condition is satisfied.

Abstract translation: 由于尽管处于低流量状态，不可能充分地减少开始无用的数量基站，而是不可能相对减小相邻小区之间的干扰和功耗。 当开始另一基站与移动台之间的通信并且满足第一预定条件时，基站开始发送具有预定功率的控制信号。

公开(公告)号：US20230170970A1

公开(公告)日：2023-06-01

申请号：US17992365

申请日：2022-11-22

Applicant: NEC Corporation

Inventor： Jun SHIKIDA ,  Kazushi MURAOKA ,  Toshiki TAKEUCHI

IPC: H04B7/06 ,  H04B17/309

CPC classification number: H04B7/0695 ,  H04B17/309

Abstract: Provided is a control apparatus configured to acquire a measurement result including information on reception qualities of a plurality of beams, update a database including information representing a relationship between the plurality of beams for each of a plurality of propagation environments, based on the measurement result, and perform selection processing for selecting a beam using the database.

公开(公告)号：US20230054311A1

公开(公告)日：2023-02-23

申请号：US17881152

申请日：2022-08-04

Applicant: NEC Corporation

Inventor： Masaaki TANIO ,  Naoto ISHII ,  Kazushi MURAOKA

IPC: H03M3/00

Abstract: A delta-sigma modulation apparatus performs delta-sigma modulation on a first signal as an input signal and outputs a second signal, outputs, using the second signal and a third signal generated through a transmission process of the second signal, a fourth signal that is an approximated value of a signal which is generated through at least part of the transmission process, and performs the delta-sigma modulation on the first signal using the fourth signal and outputs the second signal.

公开(公告)号：US20220337341A1

公开(公告)日：2022-10-20

申请号：US17673093

申请日：2022-02-16

Applicant: NEC CORPORATION ,  OSAKA UNIVERSITY ,  THE DOSHISHA

Inventor： Kazushi MURAOKA ,  Takanobu Doi ,  Naoto Ishii ,  Takumi Takahashi ,  Seiichi Sampei ,  Shinsuke Ibi

IPC: H04L1/00 ,  H04B7/0452

Abstract: A method implemented in a computer system includes training a network, which is obtained by unfolding an iterative algorithm for demodulation or demodulation and decoding, using a machine learning technique with a loss function that takes into account non-Gaussianity of a log-likelihood ratio (LLR) distribution calculated from an output of the network. The method further includes producing a first set of learned parameters of that iterative algorithm.

公开(公告)号：US20210344524A1

公开(公告)日：2021-11-04

申请号：US16975294

申请日：2019-03-08

Applicant: NEC CORPORATION

Inventor： Jun SHIKIDA ,  Kazushi MURAOKA ,  Naota ISHII

IPC: H04L25/02

Abstract: A wireless apparatus includes a channel estimation part that acquires an estimated impulse response which is an estimate value of an impulse response of a channel between a wireless terminal and the wireless apparatus, a tap location error detection part that detects a tap location error between estimated impulse responses at different time points out of the estimated impulse responses, and a channel prediction part that calculates a predicted impulse response which is an impulse response of the channel at a future time point by using the estimated impulse responses and the tap location error.