公开(公告)号：US5146359A

公开(公告)日：1992-09-08

申请号：US759036

申请日：1991-09-05

Applicant: Takanori Okoshi ,  Shinji Yamashita

Inventor： Takanori Okoshi ,  Shinji Yamashita

IPC: H04B10/148

CPC classification number: H04B10/61 ,  H04B10/613 ,  H04B10/63 ,  H04B10/64

Abstract: A double-stage phase-diversity receiver divides one signal into a plurality of signals. These divided signals are mixed with first-stage local oscillation signals having predetermined phase relations to thereby provide a plurality of electrical baseband signals. These electrical signals are up-converted by using second-stage local oscillation signals having a predetermined phase relation. The up-converted IF signals are added, and are then demodulated by a heterodyne scheme.

Abstract translation: 双级相位分集接收器将一个信号分成多个信号。 这些分频信号与具有预定相位关系的第一级本地振荡信号混合，从而提供多个电基带信号。 这些电信号通过使用具有预定相位关系的第二级本地振荡信号进行上变频。 加上变换的IF信号，然后通过外差方案进行解调。

公开(公告)号：US5115332A

公开(公告)日：1992-05-19

申请号：US553744

申请日：1990-07-18

Applicant: Takao Naito ,  Terumi Chikama ,  Shigeki Watanabe ,  Tetsuya Kiyonaga ,  Yoshihito Onoda ,  Hideo Kuwahara

Inventor： Takao Naito ,  Terumi Chikama ,  Shigeki Watanabe ,  Tetsuya Kiyonaga ,  Yoshihito Onoda ,  Hideo Kuwahara

IPC: H04B10/2513 ,  H04B10/61 ,  H04B10/63 ,  H04B10/64

CPC classification number: H04B10/61 ,  H04B10/2513 ,  H04B10/613 ,  H04B10/63 ,  H04B10/64

Abstract: A receiver for coherent optical communication in a phase diversity system. An optical hybrid circuit receives a signal beam and receives a local-oscillator beam which has a predetermined phase shift. The optical hybrid circuit branches each beam into pairs, each pair having one signal beam and one local-oscillator beam. These beam pairs are output to first and second photodetectors which each apply a photoelectric conversion, thus producing first and second output signals. The output signals are output to an electrical 90.degree. hybrid circuit which shifts the first signal by 90.degree. and adds it to the second signal to produce a first output signal, and shifts the second signal by 90.degree. and adds it to the first signal to produce a second output signal. The first and second output signals are applied to first and second demodulators, respectively, which delay the signals by a delay corresponding to their frequency. The demodulators output the delayed signals to an adder which adds the two signals to produce an output signal. As a result, the receiver is capable of compensating the wavelength dispension is an optical fiber to secure an enhanced receiving sensitivity.

公开(公告)号：US20240137127A1

公开(公告)日：2024-04-25

申请号：US18353224

申请日：2023-07-17

Applicant: Fujitsu Limited

Inventor： GUOXIU HUANG ,  Hisao NAKASHIMA

IPC: H04B10/50 ,  H04B10/61

CPC classification number: H04B10/50572 ,  H04B10/613

Abstract: An optical transmitter includes a signal processor and transmission circuit. The signal processor modulates a first signal to generate a first modulated signal, determines a modulo amplitude that is larger than an amplitude of the first modulated signal, inserts a second modulated signal into the first modulated signal to generate a transmission signal, corrects a symbol of the transmission signal by using an amplitude of one or a plurality of previous symbols to generate a pre-equalized signal, and performs modulo calculation based on the modulo amplitude on the pre-equalized signal. The transmission circuit generates a modulated optical signal based on an output signal of the signal processor and transmits the modulated optical signal to a reception node. An amplitude of the second modulated signal is equal to the modulo amplitude.

公开(公告)号：US20240121006A1

公开(公告)日：2024-04-11

申请号：US18264667

申请日：2021-12-08

Applicant: ZTE CORPORATION

Inventor： Jingsong BEI ,  Zhengxuan LI ,  Yiming ZHONG ,  Bo YANG ,  Yingxiong SONG

IPC: H04B10/61

CPC classification number: H04B10/613 ,  H04B10/6166

Abstract: A coherent detection method and device, and an optical transmission system are disclosed. The method may include: acquiring an optical transmission signal and a local oscillator signal, where a frequency value of the local oscillator signal differs from a frequency value of the optical transmission signal by a preset offset frequency value, the preset offset frequency value being smaller than a symbol rate value of the optical transmission signal; obtaining a coupled signal according to the optical transmission signal and the local oscillator signal; converting the coupled signal into an analog signal; sampling the analog signal according to a preset sampling frequency value and converting the analog signal into a plurality digital signals; and processing two digital signals among the plurality of digital signals so that a phase difference between the two digital signals to is 90 degrees.

公开(公告)号：US11711147B2

公开(公告)日：2023-07-25

申请号：US17326770

申请日：2021-05-21

Applicant: MELLANOX TECHNOLOGIES, LTD.

Inventor： Nikolaos (Nikos) Argyris ,  Yoav Rosenberg ,  Dimitrios Kalavrouziotis ,  Paraskevas Bakopoulos ,  Elad Mentovich

IPC: H04B10/40 ,  H04B10/61 ,  H04B10/112 ,  H04B10/50

CPC classification number: H04B10/40 ,  H04B10/1127 ,  H04B10/503 ,  H04B10/613

Abstract: A transceiver comprises a transmitter including a light source, a modulator coupled to the light source, a driver that drives the modulator according to a set of driving conditions to cause the modulator to output optical signals based on light from the light source, and an output that passes first portions of the optical signals output by the modulator. The transceiver further comprises a first detector that detects second portions of the optical signals output from the modulator, and a receiver including a second detector that detects optical signals from an external transmitter.

公开(公告)号：US20180152242A1

公开(公告)日：2018-05-31

申请号：US15723462

申请日：2017-10-03

Applicant: Fujitsu Optical Components Limited

Inventor： Masayuki Kurisu ,  Shuichi Yasuda

IPC: H04B10/079 ,  H04B10/61 ,  H04J14/06

CPC classification number: H04B10/0795 ,  H04B10/60 ,  H04B10/613 ,  H04B10/616 ,  H04B10/6166 ,  H04J14/02 ,  H04J14/06

Abstract: An optical receiver includes a processor. The processor calculates first through fourth optical intensities that respectively indicate input optical intensities of in-phase component in the first polarization, quadrature component in the first polarization, in-phase component in the second polarization and quadrature component in the second polarization. The processor calculates polarization dependent intensity ratio and phase dependent intensity ratio based on the first through fourth optical intensities. The processor calculates an input optical intensity of a polarization multiplexed optical signal based on an optical intensity of one of the first through fourth amplifiers, the polarization dependent intensity ratio, and the phase dependent intensity ratio.

公开(公告)号：US20180123699A1

公开(公告)日：2018-05-03

申请号：US15616844

申请日：2017-06-07

Applicant: California Institute of Technology

Inventor： Seyed Mohammadreza Fatemi ,  Seyed Ali Hajimiri ,  Behrooz Abiri ,  Aroutin Khachaturian

IPC: H04B10/61

CPC classification number: H04B10/613 ,  G01S3/782 ,  G01S3/785 ,  H04B10/11 ,  H04B10/40 ,  H04B10/50 ,  H04B10/504 ,  H04B10/60 ,  H04B10/616 ,  H04B10/673 ,  H04B10/674

Abstract: A sparse optical phased array transmitter/receiver includes, in part, a multitude of transmitting/receiving elements that are sparsely positioned. Accordingly, the transmitting/receiving elements are not uniformly distributed at equal distance intervals along a one-dimensional, two-dimensional, or a three-dimensional array. The positions of the transmitting/receiving elements may or may not conform to an ordered pattern.

公开(公告)号：US20180102838A1

公开(公告)日：2018-04-12

申请号：US15728957

申请日：2017-10-10

Applicant: Fujitsu Limited

Inventor： Cheng JU ,  Zhenning TAO

IPC: H04B10/079 ,  H04B10/61

CPC classification number: H04B10/0795 ,  H04B10/0731 ,  H04B10/079 ,  H04B10/40 ,  H04B10/50 ,  H04B10/503 ,  H04B10/60 ,  H04B10/61 ,  H04B10/613

Abstract: A measuring method and apparatus of frequency response characteristic imbalance of an optical receiver, in which by transmitting at least one single-frequency signal in an I branch or a Q branch of an optical transmitter, an amplitude ratio and phase imbalance of the I branch and the Q branch of the optical receiver are directly calculated according to at least one pair of received signals extracted from the I branch and the Q branch of the optical receiver of which frequencies are split due to a frequency difference between lasers of the optical transmitter and the optical receiver, with no need of many times of changes of central wavelengths of lasers of the optical transmitter and the optical receiver for performing measurement for many times, and measurement of frequency response characteristic imbalance of the optical receiver may be achieved through one time of measurement, which is simple in process and accurate in measurement result.

公开(公告)号：US09800348B2

公开(公告)日：2017-10-24

申请号：US14546976

申请日：2014-11-18

Applicant: Futurewei Technologies, Inc.

Inventor： Mahdi Zamani ,  Zhuhong Zhang ,  Chuandong Li

IPC: H04B10/61

CPC classification number: H04B10/6161 ,  H04B10/613 ,  H04B10/614

Abstract: An apparatus comprises a front end configured to receive an optical signal, and convert the optical signal into a plurality of digital signals, and a processing unit coupled to the front end and configured to determine a best-match chromatic dispersion (CD) estimate in the optical signal by optimizing a cost function based on signal peaks of the plurality of digital signals.

公开(公告)号：US20170163406A1

公开(公告)日：2017-06-08

申请号：US15369211

申请日：2016-12-05

Applicant: The Arizona Board of Regents on Behalf of the University of Arizona

Inventor： Stanley Johnson ,  Milorad Cvijetic

IPC: H04L7/00 ,  H04L5/00 ,  H04B10/61

CPC classification number: H04L7/0075 ,  H04B10/613 ,  H04B10/616 ,  H04B10/6161 ,  H04L5/0007

Abstract: An optical receiver includes a detector and frame synchronizer. The detector receives an optical OFDM bit stream having a plurality of frames. Each frame has an in-phase and quadrature phase component. Each component has an OFDM symbol-bearing data payload and a synchronization header. The synchronization header includes a single synchronization pulse. The frame synchronizer detects the synchronization header on each phase component. The frame synchronizer includes first and second pairs of digital comparators for each of the in-phase and quadrature phase components. The first and second pairs of digital comparators associated with each phase component establishes different and adjustable threshold windows that is symmetric about a zero amplitude of the synchronization pulse of the respective phase component. Each frame is synchronized when the synchronization pulse respectively associated therewith is detected as having an amplitude extending beyond at least one of the windows established for one of the phase components.