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公开(公告)号：US20170005733A1
公开(公告)日：2017-01-05
申请号：US15202634
申请日：2016-07-06
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger
CPC classification number: H04B10/6165 , H04B10/61 , H04B10/611 , H04B10/614 , H04L25/03057
Abstract: A receiver for an optical communications system which corrects distortion of a received signal. A clock recovery system utilising a feedback and feedforward system are provided. The feedback loop comprises a phase detector and a clock source, while the feedforward loop comprises the phase detector and a delay element for delaying the output of distortion correction system. The feedback loop has a significantly lower bandwidth than the feedforward path. There are also provided methods of optimising tap weights and of acquiring initial tap weights.
Abstract translation: 一种用于校正接收信号失真的光通信系统的接收机。 提供了一种利用反馈和前馈系统的时钟恢复系统。 反馈回路包括相位检测器和时钟源，而前馈回路包括相位检测器和用于延迟失真校正系统的输出的延迟元件。 反馈回路具有比前馈路径显着更低的带宽。 还提供了优化抽头权重和获取初始抽头权重的方法。
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公开(公告)号：US09935720B2
公开(公告)日：2018-04-03
申请号：US15644084
申请日：2017-07-07
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger , Thomas Duthel , Joerg Leykauf , Karsten Michaelsen
IPC: H04B10/61 , H04B10/532 , H04L27/00 , H04B10/516 , H04B10/556
CPC classification number: H04B10/6164 , H04B10/5161 , H04B10/532 , H04B10/5561 , H04L7/0075 , H04L27/00
Abstract: A system includes a laser configured to generate a tunable optical frequency. The system also includes an optical transmitter to map baseband data to symbols represented in a digital modulation constellation, add a frequency offset to the digital modulation constellation to cause the digital modulation constellation to rotate at a rate equal to the added frequency offset, modulate the optical frequency with the rotating digital modulation constellation, and transmit the resulting modulated optical frequency. The system also includes an optical receiver to receive the transmitted modulated optical frequency and, using the tunable optical frequency, detect the rotating digital modulation constellation conveyed by the received modulated optical frequency.
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Patent Agency Ranking
公开(公告)号：US10122470B2
公开(公告)日：2018-11-06
申请号：US15202634
申请日：2016-07-06
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger
Abstract: A receiver for an optical communications system which corrects distortion of a received signal. A clock recovery system utilizing a feedback and feedforward system are provided. The feedback loop comprises a phase detector and a clock source, while the feedforward loop comprises the phase detector and a delay element for delaying the output of distortion correction system. The feedback loop has a significantly lower bandwidth than the feedforward path. There are also provided methods of optimizing tap weights and of acquiring initial tap weights.
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公开(公告)号：US09991953B1
公开(公告)日：2018-06-05
申请号：US15398897
申请日：2017-01-05
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger , Thomas Duthel
IPC: H04B10/073 , H04B10/50
CPC classification number: H04B10/0731 , H04B10/5057
Abstract: A self-calibration procedure for an optical transmitter is provided. During the self-calibration procedure, a phase bias of an optical modulator of the optical transmitter is set so that an in-phase path and a quadrature path of the optical modulator are in phase. Stimulus signals are supplied to the in-phase and quadrature paths of the optical modulator, over a frequency range. Detection, with a photodetector, is made of an optical output of the optical modulator at a plurality of frequency steps over the frequency range. A photodetector converts an optical output of the optical modulator to an electrical signal. First and second measurement values are generated from the electrical signal output from the photodetector. A frequency spectrum and/or time delay is computed from the first and second measurement values for each frequency step value over the frequency range.
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公开(公告)号：US09735888B2
公开(公告)日：2017-08-15
申请号：US14921222
申请日：2015-10-23
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger , Thomas Duthel , Joerg Leykauf , Karsten Michaelsen
IPC: H04B10/00 , H04B10/61 , H04L7/00 , H04B10/532 , H04B10/556 , H04B10/516
CPC classification number: H04B10/6164 , H04B10/5161 , H04B10/532 , H04B10/5561 , H04L7/0075 , H04L27/00
Abstract: In an optical receiver, an optical local oscillator (LO) frequency is generated. A modulated optical frequency is received at the optical receiver. An LO-signal frequency offset between the received modulated optical frequency and the optical LO frequency is determined. A determination is made as to whether the LO-signal frequency offset is in one of multiple predefined non-overlapping target windows that cover respective non-zero LO-signal frequency offsets. If it is determined that the LO-signal frequency offset is not in one of the target windows, the optical LO frequency is tuned to drive the LO-signal frequency offset toward one of the target windows to ensure the LO-signal frequency offset is non-zero.
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公开(公告)号：US20170117969A1
公开(公告)日：2017-04-27
申请号：US14921222
申请日：2015-10-23
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger , Thomas Duthel , Joerg Leykauf , Karsten Michaelsen
IPC: H04B10/61 , H04B10/516 , H04B10/556 , H04L7/00 , H04B10/532
CPC classification number: H04B10/6164 , H04B10/5161 , H04B10/532 , H04B10/5561 , H04L7/0075 , H04L27/00
Abstract: In an optical receiver, an optical local oscillator (LO) frequency is generated. A modulated optical frequency is received at the optical receiver. An LO-signal frequency offset between the received modulated optical frequency and the optical LO frequency is determined. A determination is made as to whether the LO-signal frequency offset is in one of multiple predefined non-overlapping target windows that cover respective non-zero LO-signal frequency offsets. If it is determined that the LO-signal frequency offset is not in one of the target windows, the optical LO frequency is tuned to drive the LO-signal frequency offset toward one of the target windows to ensure the LO-signal frequency offset is non-zero.
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公开(公告)号：US20170310401A1
公开(公告)日：2017-10-26
申请号：US15644084
申请日：2017-07-07
Applicant: Cisco Technology, Inc.
Inventor： Christopher Fludger , Thomas Duthel , Joerg Leykauf , Karsten Michaelsen
IPC: H04B10/61 , H04B10/556 , H04B10/532 , H04L27/00 , H04B10/516
CPC classification number: H04B10/6164 , H04B10/5161 , H04B10/532 , H04B10/5561 , H04L7/0075 , H04L27/00
Abstract: A system includes a laser configured to generate a tunable optical frequency. The system also includes an optical transmitter to map baseband data to symbols represented in a digital modulation constellation, add a frequency offset to the digital modulation constellation to cause the digital modulation constellation to rotate at a rate equal to the added frequency offset, modulate the optical frequency with the rotating digital modulation constellation, and transmit the resulting modulated optical frequency. The system also includes an optical receiver to receive the transmitted modulated optical frequency and, using the tunable optical frequency, detect the rotating digital modulation constellation conveyed by the received modulated optical frequency.
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