公开(公告)号：US11552714B2

公开(公告)日：2023-01-10

申请号：US17197754

申请日：2021-03-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kohki Shibahara ,  Takayuki Mizuno ,  Akira Isoda ,  Yutaka Miyamoto

IPC: H04B10/69 ,  H04B1/10 ,  H04B10/2581 ,  H04J14/04 ,  H04J14/06

Abstract: A signal receiving apparatus includes at least one signal separating apparatus that separates a specific signal from a plurality of received signals. Each of the at least one signal separating apparatus includes a spatial filtering unit that separates at least one equalized signal and a decision signal outputting unit that generates a first decision signal by deciding the equalized signal and outputs the generated first decision signal. The spatial filtering unit separates the at least one equalized signal by multiplying at least the plurality of received signals among the plurality of received signals and either the first decision signal output from the decision signal outputting unit or a second decision signal output from another signal separating apparatus by predetermined weighting coefficients.

公开(公告)号：US12034269B2

公开(公告)日：2024-07-09

申请号：US17258408

申请日：2019-07-05

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takayuki Mizuno ,  Koki Shibahara ,  Akira Isoda ,  Takayuki Kobayashi ,  Yutaka Miyamoto

IPC: H01S3/067 ,  H01S3/094 ,  H01S3/10 ,  H01S3/30 ,  H04B10/2581 ,  H04B10/291 ,  H04B10/293 ,  H04J14/04

CPC classification number: H01S3/30 ,  H01S3/06737 ,  H01S3/06779 ,  H01S3/094007 ,  H01S3/10015 ,  H04B10/2581 ,  H04B10/2916 ,  H04B10/293 ,  H04J14/04

Abstract: An optical amplifier repeater system includes an optical fiber propagating a light beam in a plurality of propagation modes and an optical amplifier repeater amplifying the light beam propagated through the optical fiber. The optical amplifier repeater includes an optical demultiplexer demultiplexing the light beam in the plurality of propagation modes propagated through the optical fiber into a plurality of single-mode light beams, an optical amplifier amplifying, by simultaneous pumping, intensities of the plurality of single-mode light beams using a light beam generated by one pumping light source, an optical multiplexer multiplexing the plurality of single-mode light beams amplified by the optical amplifier into a light beam in the plurality of propagation modes, and an optical intensity adjusting unit adjusting the intensity of each of the plurality of single-mode light beams at least one of before or after the amplification by the optical amplifier. The optical intensity adjusting unit performs the adjustment by amplifying or attenuating the optical intensity of each of the plurality of single-mode light beams in an individual optical path through which the single-mode light beam is propagated.

公开(公告)号：US10985846B2

公开(公告)日：2021-04-20

申请号：US16492917

申请日：2018-03-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kohki Shibahara ,  Takayuki Mizuno ,  Akira Isoda ,  Yutaka Miyamoto

IPC: H04B10/69 ,  H04B1/10 ,  H04B10/2581 ,  H04J14/04 ,  H04J14/06

Abstract: A signal receiving apparatus includes at least one signal separating apparatus that separates a specific signal from a plurality of received signals. Each of the at least one signal separating apparatus includes a spatial filtering unit that separates at least one equalized signal and a decision signal outputting unit that generates a first decision signal by deciding the equalized signal and outputs the generated first decision signal. The spatial filtering unit separates the at least one equalized signal by multiplying at least the plurality of received signals among the plurality of received signals and either the first decision signal output from the decision signal outputting unit or a second decision signal output from another signal separating apparatus by predetermined weighting coefficients.

公开(公告)号：US11476635B2

公开(公告)日：2022-10-18

申请号：US16640242

申请日：2018-08-24

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takayuki Mizuno ,  Akira Isoda ,  Kohki Shibahara ,  Mitsunori Fukutoku ,  Yutaka Miyamoto

IPC: H01S3/23 ,  H01S3/067 ,  H01S3/094 ,  H01S3/0941 ,  H01S3/30 ,  H04B10/297 ,  H01S3/16

Abstract: An optically amplified repeater system includes optical transmission paths, a multi-channel optical amplifier, one or more Raman amplification pumping light sources, and a wavelength multiplexer. The multi-channel optical amplifier includes K simultaneous pumping light sources, N optical amplification media, and one or more optical couplers, and simultaneously amplifies, with the K simultaneous pumping light sources, light intensities of optical signals that pass through the N optical amplification media and propagate through the optical transmission paths. Light intensities of the wavelength band of the optical signals is Raman amplified by the Raman amplification pumping light. A light intensity of the Raman amplification pumping light output from the one or more Raman amplification pumping light sources is determined in accordance with characteristic differences between the optical signals passing through the optical transmission paths.

公开(公告)号：US11349564B2

公开(公告)日：2022-05-31

申请号：US17263733

申请日：2019-08-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akira Isoda ,  Takayuki Mizuno ,  Koki Shibahara ,  Takayuki Kobayashi ,  Yutaka Miyamoto

IPC: H04B10/08 ,  H04B10/077 ,  H04B10/25 ,  H04J14/06

Abstract: A crosstalk estimation system includes: a light source unit that generates a polarization-multiplexed light, which is a polarized light having multiplexed polarizations, of each wavelength in a sideband of a modulated signal and emits the polarization-multiplexed light of each wavelength; a multiplexer that multiplexes the modulated signal with the polarization-multiplexed light for each core, which is associated with one of the wavelengths; a transmission line that transmits the modulated signal multiplexed with the polarization-multiplexed light of each wavelength through a different core; a separation unit that separates the polarization-multiplexed light from the modulated signal multiplexed with the polarization-multiplexed light for each core; a measurement unit that generates light intensity data on the polarization-multiplexed light of each wavelength; and an estimation unit that estimates a crosstalk between the cores based on a difference in light intensity between the polarization-multiplexed light of the wavelengths.