公开(公告)号：US12057898B2

公开(公告)日：2024-08-06

申请号：US17797883

申请日：2020-03-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hayato Fukuzono ,  Keita Kuriyama ,  Masafumi Yoshioka ,  Takafumi Hayashi

IPC: H04B7/04 ,  H04B7/0413 ,  H04L25/02 ,  H04L27/26

CPC classification number: H04B7/0413 ,  H04L25/0212 ,  H04L27/2607

Abstract: A transmission apparatus including the number of antennas different from a reception apparatus and performing transmission by SC-MIMO to and from the reception apparatus includes a training signal generation unit that generates a known signal predetermined, a CP addition unit that adds a CP to each symbol of a transmission signal including the known signal, a weight generation unit that generates a transmission weight based on a transposed adjugate matrix that is a product of a channel matrix estimated based on the known signal by the reception apparatus and a complex conjugate transpose of the channel matrix, and a transmission beam formation unit that uses the transmission weight to form a transmission beam for the transmission signal where the CP is added.

公开(公告)号：US12199710B2

公开(公告)日：2025-01-14

申请号：US17909206

申请日：2020-03-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Takafumi Hayashi

IPC: H04B7/06 ,  H04B7/08

Abstract: A wireless communication method in a wireless communication system which includes a radio transmitting station apparatus having a plurality of antennas and a radio receiving station apparatus having an antenna and which performs transmission and reception of a radio signal with a single carrier. The wireless communication method includes: estimating a communication path matrix based on a training signal; transforming the estimated communication path matrix into a frequency domain, transforming a complex conjugate transposed matrix of each of a unitary matrix and an adjoint matrix obtained by performing singular value decomposition for each frequency with respect to the transformed frequency domain communication path matrix into a time domain, and adopting each as a reception weight matrix and a transmission weight matrix; performing transmission beam formation based on the transmission weight matrix; and performing reception beam formation based on the reception weight matrix.

公开(公告)号：US11870517B2

公开(公告)日：2024-01-09

申请号：US17602192

申请日：2020-03-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Tsutomu Tatsuta

IPC: H04B7/0456 ,  H04B7/005 ,  H04B7/06 ,  H04B7/08

CPC classification number: H04B7/0456 ,  H04B7/005 ,  H04B7/06 ,  H04B7/08

Abstract: According to the present invention, in a wireless communication system that performs single carrier MIMO transmission between a transmitting station device and a receiving station device, the transmitting station device includes a time-domain linear equalization unit, a propagation path characteristics estimation unit configured to receive a training signal and estimate a transfer function matrix of propagation path characteristics, a filter tap calculation unit configured to calculate filter tap coefficients for the time-domain linear equalization unit based on the transfer function matrix by a predefined approach, and a transmission mode determination unit configured to make the filter tap calculation unit calculate the filter tap coefficients when the transfer function matrix meets a predefined condition, and to change a transmission mode and determine the transmission mode that meets the predefined condition when the transfer function matrix does not meet the predefined condition. The receiving station device includes a training signal generation unit configured to generate the training signal for use in estimation of propagation path characteristics and transmit the training signal to the transmitting station device.

公开(公告)号：US11901980B2

公开(公告)日：2024-02-13

申请号：US17909161

申请日：2020-03-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Takafumi Hayashi

IPC: H04B7/04 ,  H04B7/0456

CPC classification number: H04B7/0456

Abstract: A wireless communication method in a wireless communication system which includes a radio transmitting station apparatus having a plurality of antennas and a radio receiving station apparatus having an antenna and which performs transmission and reception of a radio signal with a single carrier, the wireless communication method including: the radio receiving station apparatus or the radio transmitting station apparatus estimating a communication path matrix based on a training signal; the radio receiving station apparatus or the radio transmitting station apparatus transforming the communication path matrix into a frequency domain, calculating a pseudo inverse matrix for each frequency with respect to the transformed frequency domain communication path matrix, and transforming the calculated pseudo inverse matrix into a time domain and adopting as a transmission weight matrix; and the radio transmitting station apparatus forming a transmission beam based on the transmission weight matrix.

公开(公告)号：US11736168B2

公开(公告)日：2023-08-22

申请号：US17636180

申请日：2019-09-06

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Tsutomu Tatsuta

IPC: H04B7/06 ,  H04B7/0413

CPC classification number: H04B7/0617 ,  H04B7/0413

Abstract: A transmitting station device at least comprises a training signal generation unit, and a receiving station device at least comprises a communication path estimation unit which estimates a communication path response from the known signal, and a beam forming unit which performs a beam forming process using a weight to suppress inter-stream interference, a channel fluctuation amount calculation unit which calculates as a channel fluctuation amount a difference between the communication path responses estimated in a manner of one following another in time, and a weight calculation unit which calculates a new weight using an updated value of the weight calculated based on the channel fluctuation amount are included in one of the transmitting station device and the receiving station device. This can significantly reduce the amount of calculation related to update of a weight.

公开(公告)号：US11283492B2

公开(公告)日：2022-03-22

申请号：US17287066

申请日：2019-10-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Tsutomu Tatsuta

IPC: H04B7/0417 ,  H04L27/01 ,  H04L25/03

Abstract: According to the present invention, a transmitting station apparatus includes: a plurality of modulation units that modulates a plurality of streams into which transmission data is divided to generate a plurality of first data signals; a training signal generation unit that generates a known training signal; a linear equalization unit that linearly equalizes the plurality of first data signals using a tap coefficient for removing inter-antenna interference and inter-symbol interference and outputs second data signals on which transmission beam forming and equalization are simultaneously performed; and a plurality of transmitting station communication units that transmit the training signal or the second data signals to a receiving station apparatus and receive the tap coefficient from the receiving station apparatus, and a receiving station apparatus includes: a coefficient estimation unit that estimates a channel impulse response from the training signal and calculates the tap coefficient based on the channel impulse response; and a receiving station communication unit that receives the second data signals or the training signal and transmits the tap coefficient calculated by the coefficient estimation unit to the transmitting station apparatus.

公开(公告)号：US12166549B2

公开(公告)日：2024-12-10

申请号：US17635457

申请日：2019-08-20

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Tsutomu Tatsuta

IPC: H04B7/0452 ,  H04B7/06 ,  H04B17/336

Abstract: In a wireless communication system for performing single-carrier MIMO transmission, a transmitting station apparatus includes a training signal generation unit and a transmit beamforming unit that performs transmit beamforming processing using transmit weights and a receiving station apparatus includes a communication path estimation unit, an interference amount determination unit that determines whether or not a residual inter-stream interference exceeds a predetermined threshold value, a receive weight calculation unit that calculates a receive weight used for receive beamforming processing when the residual inter-stream interference exceeds the threshold value, and a receive beamforming unit that performs receive beamforming processing for suppressing residual inter-stream interferences using the receive weight.

公开(公告)号：US12088374B2

公开(公告)日：2024-09-10

申请号：US17630227

申请日：2019-08-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hayato Fukuzono ,  Keita Kuriyama ,  Masafumi Yoshioka ,  Tsutomu Tatsuta

IPC: H04B7/06 ,  H04B7/0452 ,  H04L27/26

CPC classification number: H04B7/0617 ,  H04B7/0452 ,  H04B7/0626 ,  H04L27/2607

Abstract: A transmission station device includes a training signal generation unit, a CP addition unit, and a transmission beamforming unit that performs transmission beamforming processing in a time domain using a transmission weight for removing inter-antenna interference. A reception station device includes a CP removal unit, a channel estimation unit, and an equalization unit that performs equalization processing for removing inter-symbol interference in a frequency domain using a reception weight. Either of the transmission station device or the reception station device is provided with a weight calculation unit that calculates the transmission weight and the reception weight based on the channel response, an effective CIR length calculation unit that calculates an effective CIR length between antennas, and a CP length setting unit that sets, to the CP length, a maximum CIR length among the CIR lengths of respective items of the reception weight.

公开(公告)号：US11929797B2

公开(公告)日：2024-03-12

申请号：US17797758

申请日：2020-03-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hayato Fukuzono ,  Keita Kuriyama ,  Masafumi Yoshioka ,  Takafumi Hayashi

IPC: H04K1/10 ,  H04B7/0413 ,  H04L25/02 ,  H04L27/26 ,  H04L27/28

CPC classification number: H04B7/0413 ,  H04L25/0202 ,  H04L27/2607

Abstract: A transmission apparatus including the number of antennas different from a reception apparatus and performing transmission by SC-MIMO to and from the reception apparatus includes a training signal generation unit that generates a known signal predetermined, a CP addition unit that adds a CP to each symbol of a transmission signal including the known signal, a weight generation unit that multiplies a channel matrix estimated based on the known signal by the reception apparatus by a pseudo-inverse matrix obtained by a predetermined number of iterative calculations to generate a transmission weight that is diagonalizable, and a transmission beam formation unit that uses the transmission weight to form a transmission beam for the transmission signal where the CP is added.

公开(公告)号：US11843429B2

公开(公告)日：2023-12-12

申请号：US17602152

申请日：2020-03-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Masafumi Yoshioka ,  Tsutomu Tatsuta

IPC: H04B7/02 ,  H04B7/0456

CPC classification number: H04B7/0456

Abstract: According to the present invention, in a wireless communication system that performs single carrier MIMO transmission between a transmitting station device and a receiving station device, the transmitting station device including: a time-domain linear equalization unit configured to remove inter-symbol interference and inter-stream interference from a data signal to be transmitted to the receiving station device; a propagation path characteristics estimation unit configured to receive a training signal which is transmitted by the receiving station device and estimate a transfer function matrix of propagation path characteristics; and a filter tap calculation unit configured to calculate filter tap coefficients for the time-domain linear equalization unit by representing the estimated transfer function matrix as a matrix polynomial, taking an inverse response of the matrix polynomial as a transmit weight matrix, and approximating the transmit weight matrix with Neumann series, and the receiving station device including a training signal generation unit configured to generate the training signal for use in estimation of propagation path characteristics and transmit it to the transmitting station device.