公开(公告)号：US11539431B1

公开(公告)日：2022-12-27

申请号：US17577488

申请日：2022-01-18

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Zhiping Jiang ,  Junho Chang ,  Choloong Hahn

IPC: H04B10/079

Abstract: The disclosed systems and methods for optical filter fault localization. The optical filter fault localization is based on: i) determining an accumulated noise density at frequencies where ASE noise is filtered out by a faulty optical filter in an optical signal; ii) comparing the accumulated noise density with predicted accumulated noise densities, the predicted accumulated noise densities representing noises predicted from a plurality of optical filters to a receiver; and iii) determining, based on the comparison of the accumulated noise density and the predicted accumulated noise densities, a location of the faulty optical filter.

公开(公告)号：US11528050B1

公开(公告)日：2022-12-13

申请号：US17518928

申请日：2021-11-04

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Zhiping Jiang ,  Xuefeng Tang ,  Junho Chang

IPC: H04B1/44 ,  H04B1/10 ,  H04B1/04 ,  H04B1/54 ,  H04B1/16

Abstract: The disclosed systems and methods for detecting mirror crosstalk between frequency bands equally above and below the center frequency of a Digital Subcarrier Multiplexing system include: a transmitter configured to insert zero-power symbols on half the frequency bands below center frequency, and insert other zero-power symbols, partially overlapping in time with the first zero-power symbols, on the other half of the frequency bands above center frequency. A receiver zeroes out ASE and other noises during the overlapping portion of all the zero-power symbols, then uses the power detected during the remaining portion of each zero-power symbol in each frequency band to accurately evaluate the mirror crosstalk from the corresponding frequency band on the opposite side of center frequency.

公开(公告)号：US20250132828A1

公开(公告)日：2025-04-24

申请号：US18492905

申请日：2023-10-24

Applicant: Huawei Technologies Co., Ltd.

Inventor： Zhiping Jiang ,  Choloong Hahn ,  Junho Chang

IPC: H04B10/079

Abstract: A method for monitoring impairment includes: receiving a first received waveform sent by the coherent receiver; obtaining a second received waveform including a first sub-waveform and a second sub-waveform with a relative first delay therebetween according to the first received waveform; obtaining a template at a predetermined location on the fiber link according to the second received waveform, wherein the template is used for representing a nonlinear noise by a first sub-signal waveform and a second sub-signal waveform at the predetermined location that are respectively obtained from the first sub-waveform and the second sub-waveform and have the first delay therebetween; obtaining a correlation between the second received waveform and the template; changing a value of the first delay to obtain values of the correlation corresponding to different values of the first delay; and outputting a value of the first delay corresponding to a maximum value of the correlation as impairment estimation.

公开(公告)号：US20250088283A1

公开(公告)日：2025-03-13

申请号：US18464825

申请日：2023-09-11

Applicant: Huawei Technologies Co., Ltd.

Inventor： Zhiping Jiang ,  Choloong Hahn ,  Junho Chang

IPC: H04B10/58 ,  H04B10/2543 ,  H04B10/61

Abstract: A method for monitoring generalized optical signal-to-noise ratio (gOSNR) is provided, which is applied to monitoring of an optical signal received by a coherent receiver through a fiber link. The method includes: obtaining a first received waveform; obtaining a signal part of the first received waveform; obtaining a noise part of the first received waveform according to the signal part and the first received waveform; obtaining a first correlation between the noise part and a first template at a predetermined location on the fiber link, the first correlation indicating a signal power at the predetermined location; obtaining a second correlation between the noise part and a second template at the predetermined location on the fiber link, the second correlation indicating a signal power and noise power at the predetermined location; and obtaining gOSNR at the predetermined location according to the first correlation and the second correlation.