公开(公告)号：US20240421910A1

公开(公告)日：2024-12-19

申请号：US18274148

申请日：2021-02-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Yoichi FUKADA ,  Akihiro TANABE ,  Ryo MIYATAKE

IPC: H04B10/516 ,  H04J14/02

Abstract: An optical transmission apparatus includes: a distributing unit which distributes a laser beam based on a first oscillation frequency; a phase modulator which generates, using the laser beam based on the first oscillation frequency, a phase-modulated signal that is an optical signal phase-modulated in accordance with a modulated signal; a multiplexing unit which multiplexes a laser beam based on a second oscillation frequency and the phase-modulated signal; a detecting unit which generates a frequency-modulated signal by performing detection processing on a result of multiplexing of the laser beam based on the second oscillation frequency and the phase-modulated signal; and an intensity modulator which generates, using the laser beam based on the first oscillation frequency, an optical signal intensity-modulated in accordance with the frequency-modulated signal.

公开(公告)号：US20240356654A1

公开(公告)日：2024-10-24

申请号：US18683712

申请日：2021-08-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Yoichi FUKADA ,  Akihiro TANABE ,  Ryo MIYATAKE

IPC: H04B10/54 ,  H04B10/508 ,  H04J1/00

CPC classification number: H04B10/54 ,  H04B10/508 ,  H04J1/00

Abstract: There is provided a signal amplification method executed by an optical reception device, the method including: an electrical conversion step of converting an optical intensity modulation signal according to a frequency modulation signal which is converted from a frequency division multiplexing signal into the frequency modulation signal; a delay control step of controlling a delay amount of the frequency modulation signal based on a center frequency of the frequency modulation signal and a shift amount of a highest frequency of the frequency modulation signal; a delay detection step of demodulating the frequency modulation signal into the frequency division multiplexing signal by executing demodulation processing based on delay detection on the frequency modulation signal of which the delay amount is controlled; an amplification factor derivation step of deriving an amplification factor of the demodulated frequency division multiplexing signal based on the delay amount; and an amplification step of amplifying the demodulated frequency division multiplexing signal by the amplification factor.

公开(公告)号：US20230275658A1

公开(公告)日：2023-08-31

申请号：US18016367

申请日：2020-07-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiaki SHITABA ,  Tomoaki YOSHIDA ,  Akihiro TANABE ,  Takashi MITSUI

IPC: H04B10/077 ,  H04B10/61

CPC classification number: H04B10/077 ,  H04B10/614

Abstract: In an optical transmission system including a plurality of optical transmitting units and a relay device, the plurality of optical transmitting units include a frequency modulation conversion unit that converts an input signal into a frequency modulation signal through frequency modulation conversion processing, a multiplexing unit that multiplexes monitoring signals with different frequencies with the frequency modulation signal, and an optical modulation unit that converts the frequency modulation signal that is an electric signal in which the monitoring signals are multiplexed into optical signals having different wavelengths, and the relay device includes a photoelectric conversion unit that acquires a combined signal obtained by combining optical signals having different wavelengths from each other and converts the combined signal into an electric signal, and a measuring unit that measures transmission quality of the plurality of monitoring signals included in the electric signal.

公开(公告)号：US20230254060A1

公开(公告)日：2023-08-10

申请号：US18012076

申请日：2020-07-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akihiro TANABE ,  Toshiaki SHITABA ,  Takashi MITSUI ,  Tomoaki YOSHIDA

IPC: H04J14/02

CPC classification number: H04J14/0298

Abstract: An apparatus includes a reception processing unit configured to output a frequency division multiplexed signal obtained from a transmission signal transmitted over the wired communication network, an output control unit configured to output, in a case that apparatus identifying data matches signal specifying data, a frequency band specifying data indicating a frequency band corresponding to the signal specifying data, the apparatus identifying data being for requesting signal quality degradation, and the signal specifying data specifying a carrier signal requesting signal quality degradation among a plurality of carrier signals included in the frequency division multiplexed signal, a disturbing signal generation unit configured to generate a disturbing signal in a frequency band corresponding to the frequency band specifying data output by the output control unit, and a multiplexing unit configured to multiplex the frequency division multiplexed signal and the disturbing signal to output.

公开(公告)号：US20220140906A1

公开(公告)日：2022-05-05

申请号：US17426817

申请日：2020-01-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MITSUI ,  Toshiaki SHITABA ,  Akihiro TANABE ,  Kengo HORIKOSHI ,  Hisao YOSHINAGA

IPC: H04B10/293 ,  H04B10/572

Abstract: An optical transmission system includes: a first optical transmitting unit for transmitting a first optical signal having a first wavelength; a second optical transmitting unit for transmitting a second optical signal having a second wavelength; an output adjustment unit for acquiring the first optical signal and the second optical signal, adjusting signal intensities of the acquired optical signals, and outputting the optical signals; a multiplexer for multiplexing the first optical signal and the second optical signal that have been subjected to signal intensity adjustment and outputting a multiplexed signal; an amplifier for amplifying the multiplexed signal; a first optical receiving unit for receiving the amplified first optical signal; and a second optical receiving unit for receiving the amplified second optical signal. The output adjustment unit adjusts the signal intensities of the first optical signal and the second optical signal such that the signal intensity of the first optical signal received by the first optical receiving unit is larger than or equal to a first predetermined value, and the signal intensity of the second optical signal received by the second optical receiving unit is larger than or equal to a second predetermined value.