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.

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.

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.

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.