ESTIMATION METHOD, OPTICAL RECEIVING APPARATUS, AND COMPUTER PROGRAM

    公开(公告)号:US20250038860A1

    公开(公告)日:2025-01-30

    申请号:US18717067

    申请日:2022-01-04

    Abstract: An estimation method in an optical transmission system that performs communication by a digital coherent system including an optical transmission device and an optical reception device, the estimation method including calculating a ratio of a linearly transformed amount after converting a tap coefficient of a digital filter included in the optical reception device into a frequency domain signal by digital Fourier transform, and estimating a physical quantity related to at least a response between the optical transmission device and the optical reception device based on amplitude and phase information of the ratio of the calculated linearly transformed amount.

    OPTICAL TRANSMISSION SYSTEM
    2.
    发明申请

    公开(公告)号:US20210367670A1

    公开(公告)日:2021-11-25

    申请号:US17291170

    申请日:2019-11-07

    Abstract: An optical transmission system including an optical transmitter and an optical receiver, wherein the optical transmitter includes a signal coding unit that performs non-linear block coding on an M (M is an integer greater than or equal to 1)-value symbol sequence or a bit sequence input as data information to generate an L (L is an integer greater than or equal to 2, L>M)-value symbol sequence that corresponds to the M-value symbol sequence or the bit sequence in one-to-one correspondence, a digital-to-analog conversion unit that converts the generated L-value symbol sequence to an analog signal, and a modulator that generates an optical modulation signal by performing modulation based on the analog signal, and the optical receiver includes a light receiving unit that receives the optical modulation signal transmitted from the optical transmitter and converts the optical modulation signal to an electrical signal, and a signal decoding unit that restores the M-value symbol sequence or the bit sequence by performing processing that is the reverse of processing performed by the signal coding unit, on the electrical signal.

    OPTICAL RECEIVING APPARATUS AND WAVEFORM DISTORTION COMPENSATION METHOD

    公开(公告)号:US20220094440A1

    公开(公告)日:2022-03-24

    申请号:US17420845

    申请日:2020-01-06

    Abstract: An optical receiving device that divides receive signals obtained by receiving an optical signal using a coherent detection scheme into a plurality of frequency bands, matches timing of the receive signals along a time axis between the frequency bands resulting from the division, performs a combining process of combining the receive signals contained in the plurality of frequency bands, and compensates the receive signals for waveform distortion either before or after the combining process, includes: a first wavelength dispersion compensation unit adapted to compensate the receive signals for waveform distortion in each of the frequency bands resulting from the division; a first nonlinear compensation unit adapted to compensate the receive signals belonging to each of the frequency bands and timed with each other in a time domain for a nonlinear optical effect; and a second wavelength dispersion compensation unit adapted to compensate the receive signals belonging to each of the frequency bands and compensated for the nonlinear optical effect for wavelength dispersion in each of the frequency bands.

    WAVELENGTH DISPERSION COMPENSATION APPARATUS, WAVELENGTH DISPERSION COMPENSATION METHOD, AND OPTICAL RECEIVING APPARATUS

    公开(公告)号:US20220038180A1

    公开(公告)日:2022-02-03

    申请号:US17278627

    申请日:2019-08-27

    Abstract: Provided is a chromatic dispersion compensation method including: dividing a reception signal obtained by receiving an optical signal using a coherent detection scheme into a plurality of frequency bands; adjusting a timing on a time axis of the reception signal for each of the divided frequency bands; performing combination processing for combining the reception signals included in the plurality of frequency bands; performing chromatic dispersion compensation on the reception signal at any timing before or after the combination processing; selecting, before the combination processing, sections in which overlapping parts determined based on lengths of overlap parts are generated; outputting the reception signal for each of the selected sections as a division processing block; and removing the overlap parts from both ends of a processing block generated by combination of the division processing blocks in the combination processing so as to be continuous on a frequency axis.

    OPTICAL TRANSMISSION CONTROL METHOD AND OPTICAL TRANSMISSION SYSTEM

    公开(公告)号:US20210211218A1

    公开(公告)日:2021-07-08

    申请号:US17059238

    申请日:2019-05-20

    Abstract: An optical transmission system includes an optical transmitter, an optical receiver, and a control apparatus. The control apparatus repeatedly performs an adjustment process for adjusting power of an optical signal of a frequency band to be adjusted while switching the frequency band to be adjusted between at least two frequency bands including at least a frequency band where stimulated Raman scattering occurs among frequency bands that are multiplexed in a multiplexed optical signal transmitted by the optical transmission system. In the adjustment process, when power of an optical signal of the frequency band to be adjusted transmitted from the optical transmitter has been changed, the control apparatus determines the power of the optical signal of the frequency band to be adjusted on the basis of a signal quality measured by the optical receiver that has received the optical signal.

Patent Agency Ranking