公开(公告)号：US20240146581A1

公开(公告)日：2024-05-02

申请号：US17977605

申请日：2022-10-31

Applicant: NEC Corporation

Inventor： Prakash CHAKI ,  Jun Shikida ,  Kazushi Muraoka ,  Takanobu Doi

IPC: H04L25/02

CPC classification number: H04L25/0212 ,  H04L25/022 ,  H04L25/0224

Abstract: A communication device includes: a wireless transceiver configured to communicate with another communication device through a wireless channel; and at least one processor configured to execute instructions to: a) estimate at least one first channel response of the wireless channel based on a predetermined signal received from the another communication device; and b) predict a second channel response based on the at least one first channel response by an extrapolation method for signal transmission to the another communication device at a time instant where no channel estimation is performed.

公开(公告)号：US10819404B2

公开(公告)日：2020-10-27

申请号：US16616681

申请日：2018-05-28

Applicant: NEC Corporation

Inventor： Jun Shikida ,  Naoto Ishii

IPC: H04B7/0456 ,  H04L25/02 ,  H04W16/28 ,  H04B17/318

Abstract: A wireless apparatus includes a first weight multiplication part, a channel estimation part, a channel response conversion part, and a second weight generation part. The first weight multiplication part includes first weights, each of which corresponds to an individual one of a plurality of beams, and multiplies a signal(s) corresponding to a reference signal(s) transmitted from a wireless terminal(s) by the first weights. The channel estimation part estimates first channel responses for the respective beams by using the signals obtained by the multiplication by the first weights. The channel response conversion part converts the first channel responses into second channel responses by using the first weights. The second weight generation part generates second weights used for wireless communication with the wireless terminal(s) by using the second channel responses.

公开(公告)号：US20250113212A1

公开(公告)日：2025-04-03

申请号：US18833009

申请日：2022-03-08

Applicant: NEC Corporation

Inventor： Jun Shikida ,  Kazushi Muraoka

IPC: H04W16/28 ,  H04B17/309 ,  H04B17/318

Abstract: An object of the present disclosure is to provide a wireless communication apparatus, a wireless communication system, a scheduling method, and a non-transitory computer-readable medium which are capable of reducing an amount of calculation for selecting a combination of wireless devices to be spatially multiplexed while suppressing degradation of communication quality. A wireless communication apparatus according to the present disclosure includes: an acquisition unit that acquires measurement results of reception quality of a plurality of beams received by a plurality of wireless devices from each of the plurality of wireless devices; a calculation unit that calculates degrees of similarity in the reception quality between the plurality of wireless devices based on the measurement results; and a selection unit that selects a combination of wireless devices to be spatially multiplexed from among the plurality of wireless devices based on the degrees of similarity.

公开(公告)号：US20230388157A1

公开(公告)日：2023-11-30

申请号：US18031253

申请日：2020-10-27

Applicant: NEC Corporation

Inventor： Jun Shikida ,  Kazushi Muraoka

IPC: H04L25/02 ,  G06F17/16

CPC classification number: H04L25/0248 ,  G06F17/16

Abstract: An eigenvalue decomposition apparatus includes: first generation means for inputting a first matrix and generating a 2×2-dimensional third matrix using a plurality of elements included in a second matrix based on the first matrix; first calculation means for calculating a two-dimensional eigenvector that corresponds to a maximum eigenvalue of the third matrix; first update means for generating a fourth matrix obtained by reducing the dimension of the second matrix by using the two-dimensional eigenvector, updating the second matrix based on the fourth matrix, and determining, when the number of elements included in the fourth matrix is one, the element included in the fourth matrix to be an eigenvalue of the first matrix; and second calculation means for determining the eigenvector of the first matrix using the two-dimensional eigenvectors calculated before the number of elements included in the fourth matrix becomes one.

公开(公告)号：US09998937B2

公开(公告)日：2018-06-12

申请号：US14890981

申请日：2014-05-12

Applicant: NEC Corporation

Inventor： Hiroto Sugahara ,  Jun Shikida ,  Hiroaki Aminaka ,  Toshifumi Nakamura

IPC: H04W24/08 ,  H04W24/02 ,  H04L5/00 ,  H04L12/26

CPC classification number: H04W24/08 ,  H04L5/006 ,  H04L43/0882 ,  H04W24/02

Abstract: A method and a device for estimating a communication load, as well as a radio station and an upper-level apparatus in a radio communication system, are provided that can estimate a communication load in a target network with high accuracy by using received quality information. A communication load estimation function (1) for estimating a communication load in a network (NW) estimates the communication load in the network by using at least a first quality indicator (Q1), which is a quality measurement value including entire received power, and a second quality indicator (Q2), which is a quality measurement value including the signal-to-noise-and-interference ratio of a reference signal.

公开(公告)号：US11418227B2

公开(公告)日：2022-08-16

申请号：US17282469

申请日：2019-08-27

Applicant: NEC Corporation

Inventor： Jun Shikida ,  Naoto Ishii

IPC: H04B1/10 ,  H04B7/0456 ,  H04B7/06 ,  H04B7/10 ,  H04L25/02

Abstract: A radio apparatus capable of reducing the amount of calculation required to suppress an interference signal is provided. A radio apparatus (1) includes a spatial transformation unit (2) configured to perform a spatial transformation on a received signal including a desired signal and an interference signal received by a plurality of antennas, and thereby calculate a first beam-space received signal vector, a beam selecting unit (3) configured to select at least two elements from the first beam-space received signal vector and generate a second beam-space received signal vector, and an interference suppression synthesis unit (4) configured to estimate a covariance matrix of an interference noise signal including a noise signal and the interference signal included in the second beam-space received signal vector, generate a reception weight by using this covariance matrix, and detect the desired signal based on the reception weight and the second beam-space received signal vector.

公开(公告)号：US11251856B2

公开(公告)日：2022-02-15

申请号：US17228832

申请日：2021-04-13

Applicant: NEC Corporation

Inventor： Jun Shikida ,  Naoto Ishii

IPC: H04B7/10 ,  H04L1/02 ,  H04B7/08

Abstract: A control apparatus includes a determination unit configured to determine first and second reception weight matrixes by using first and second channel matrixes between first and second radio apparatuses and the first and second terminals, a first calculation unit configured to calculate a data channel matrix of a data signal transmitted from the first radio apparatus to the first terminal by using the first channel matrix and the first reception weight matrix, a second calculation unit configured to calculate an interference channel matrix of interference to the second terminal caused by the first radio apparatus by using a third channel matrix between the first radio apparatus and the second terminal and the second reception weight matrix, and a third calculation unit configured to calculate a transmission weight matrix for transmitting a data signal so that the interference is suppressed by using the data channel matrix and the interference channel matrix.

公开(公告)号：US11196468B2

公开(公告)日：2021-12-07

申请号：US17078595

申请日：2020-10-23

Applicant: NEC CORPORATION

Inventor： Jun Shikida ,  Naoto Ishii

IPC: H04B7/0456 ,  H04L5/00

Abstract: A control apparatus includes a calculation unit configured to calculate, for each of radio apparatuses, a combination of a pre-coding weight and a post-coding weight using a first channel information matrix based on estimated values of channel responses between each of the radio apparatuses and each of terminals, a selection unit configured to select one combination from the combinations calculated using the first channel information matrices as a first combination, and an orthogonalization unit configured to generate a second channel information matrix for each of the radio apparatuses by projecting each first channel information matrix onto the subspace that is orthogonal to the post-coding weight included in the first combination. The calculation unit calculates a combination for each of the radio apparatuses using a second channel information matrix, and the selection unit selects one combination from the combinations calculated using the second channel information matrix as a second combination.

公开(公告)号：US10992499B2

公开(公告)日：2021-04-27

申请号：US17043308

申请日：2019-01-30

Applicant: NEC CORPORATION

Inventor： Jun Shikida ,  Kazushi Muraoka ,  Naoto Ishii

IPC: H04B7/06 ,  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.