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：US11838167B2

公开(公告)日：2023-12-05

申请号：US17596064

申请日：2020-05-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hayato Fukuzono ,  Tomohiro Tokuyasu ,  Keita Kuriyama ,  Hiroyuki Furuya ,  Yu Ono ,  Tsutomu Tatsuta ,  Tomohiro Nakayama

IPC: H04L27/36 ,  H04W72/08 ,  H04W28/18 ,  H04W72/54

CPC classification number: H04L27/36 ,  H04W28/18 ,  H04W72/54

Abstract: Provided is a wireless communication system configured to accommodate a plurality of circuits to transmit a signal from a transmitter to a receiver, the system including a number-of-circuits observation unit configured to observe the number of circuits among the plurality of circuits through which communication is being performed; a quality observation unit configured to observe a quality of each of a plurality of communications; a determination unit configured to determine a modulation scheme for transmitting a signal based on the number of circuits observed by the number-of-circuits observation unit, the quality of each of the plurality of communications observed by the quality observation unit, and a required throughput of each of the plurality of circuits; and a modulation unit configured to modulate the signal using the modulation scheme determined by the determination unit.

公开(公告)号：US11677597B2

公开(公告)日：2023-06-13

申请号：US17595055

申请日：2019-05-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hayato Fukuzono ,  Keita Kuriyama ,  Tomohiro Tokuyasu ,  Tsutomu Tatsuta

IPC: H04L27/01

CPC classification number: H04L27/01

Abstract: A wireless communication device includes an estimation observation unit that observes a channel condition by estimating a tendency of a long delay wave and a channel fluctuation from a received signal in which a training signal is added to a data frame, a first equalizer that compensates for the received signal, a second equalizer that compensates for the received signal with a property of having a higher long delay wave tolerance and a lower channel fluctuation tolerance than the first equalizer, and a control unit that performs control which switches such that the first equalizer or the second equalizer performs compensation for the received signal, on the basis of the channel condition observed by the estimation observation unit.

公开(公告)号：US11489557B2

公开(公告)日：2022-11-01

申请号：US17433443

申请日：2020-02-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Tsutomu Tatsuta

IPC: H04B7/005 ,  H04B1/04 ,  H04B7/0417 ,  H04L27/01

Abstract: In the present invention, a transmitting station apparatus includes a training signal generation unit, a transmission end linear equalization unit configured to output a plurality of second data signals obtained by equalizing IAI of a plurality of first data signals by using a transmission end transfer function for equalizing IAI, and a transmitting station communication unit configured to transmit a training signal or the plurality of second data signals to a receiving station apparatus and receive information on the transmission end transfer function from the receiving station apparatus, and the receiving station apparatus includes a communication path estimation unit configured to estimate a communication path response from the training signal received by the receiving station communication unit, a reception end coefficient calculation unit configured to calculate the transmission end transfer function and a reception end transfer function for equalizing ISI, based on the communication path response, and a reception end linear equalization unit configured to output a plurality of third data signals obtained by equalizing ISI from the plurality of second data signals received by the receiving station communication unit by using the reception end transfer function.

公开(公告)号：US11979898B2

公开(公告)日：2024-05-07

申请号：US17596160

申请日：2020-05-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomohiro Tokuyasu ,  Hiroyuki Furuya ,  Hayato Fukuzono ,  Yu Ono ,  Tsutomu Tatsuta ,  Tomohiro Nakayama

IPC: H04W72/542 ,  H04W72/23

CPC classification number: H04W72/542 ,  H04W72/23

Abstract: A wireless communication system includes a plurality of sets of base station devices and terminal station devices configured to perform communications in an equal frame length using a time division duplex scheme, the communications of the plurality of sets being simultaneously operated in adjacent areas, in which each of the base station devices includes a control unit configured to control a transmission timing of a downlink signal transmitted from the base station device itself based on a communication distance between the base station device and the terminal station device of each of the sets or a reception timing of a downlink signal in the terminal station device such that reception timings of downlink signals transmitted from the base station device itself and other base station devices in the terminal station devices of the sets fall within a predetermined range determined in advance.

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：US11646772B2

公开(公告)日：2023-05-09

申请号：US17433475

申请日：2020-02-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keita Kuriyama ,  Hayato Fukuzono ,  Tsutomu Tatsuta

IPC: H03H7/30 ,  H04B7/0417 ,  H04B7/005

CPC classification number: H04B7/0417 ,  H04B7/005

Abstract: A transmitting station apparatus includes a training signal generation unit, a transmission end linear equalization unit configured to equalize data signals by a transmission end transfer function, and a transmitting station communication unit configured to transmit a training signal or a plurality of data signals and receive information of the transmission end transfer function from a receiving station apparatus. The receiving station apparatus includes a communication path estimation unit configured to estimate a communication path response from the training signal, a reception end coefficient calculation unit configured to calculate the transmission end transfer function with an adjugate matrix of a transfer function matrix H of the communication path response as a transfer function and a reception end transfer function with an inverse of a determinant of the transfer function matrix H as a transfer function, and a reception end linear equalization unit configured to equalize reception signals by using the reception end transfer function. The reception end linear equalization unit determines whether the determinant of the transfer function matrix H is a minimum phase, performs a forward direction equalization in a case of the minimum phase, and performs an inverse direction equalization in a case of a non-minimum phase.

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.