公开(公告)号：US11309973B2

公开(公告)日：2022-04-19

申请号：US15885385

申请日：2018-01-31

Applicant: Nokia Solutions and Networks OY

Inventor： Vincent Houtsma ,  Doutje van Veen

IPC: H04B10/00 ,  H04B10/64 ,  H04J14/08 ,  H04B10/572 ,  H04B10/079

Abstract: A passive optical network having an optical-signal monitor configured to monitor carrier-wavelength drifts during optical bursts transmitted between the optical line terminal and optical network units thereof. In an example embodiment, the optical-signal monitor uses heterodyne beating between two differently delayed portions of an optical burst to generate an estimate of the carrier-wavelength drift during that optical burst. The passive optical network may also include an electronic controller configured to use the estimates generated by the optical-signal monitor to make configuration changes at the optical network units and/or implement other control measures directed at reducing to an acceptable level the amounts of carrier-wavelength drift during the optical bursts and/or mitigating some adverse effects thereof.

公开(公告)号：US20190207702A1

公开(公告)日：2019-07-04

申请号：US15858449

申请日：2017-12-29

Applicant: Nokia Solutions and Networks OY

Inventor： Doutje van Veen ,  Vincent Houtsma

IPC: H04J14/08 ,  H04B10/61 ,  H04B10/50 ,  H04B10/27 ,  H04B10/572

CPC classification number: H04J14/08 ,  H04B10/27 ,  H04B10/272 ,  H04B10/503 ,  H04B10/572 ,  H04B10/61 ,  H04B10/616 ,  H04J14/0221 ,  H04J14/0246 ,  H04J14/0282 ,  H04Q11/0067

Abstract: A coherent optical receiver capable of receiving data encoded in optical bursts whose optical power can vary significantly from burst to burst. In an example embodiment, the coherent optical receiver comprises a variable optical attenuator connected between an optical local oscillator and an optical hybrid and configured to controllably vary the intensity of the local-oscillator signal in response to a control signal generated by a control circuit. In an example embodiment, the control circuit is configured to generate the control signal for the variable optical attenuator using power-control settings read from a memory and further using a transmission schedule according to which different remote optical transmitters are scheduled to transmit their respective optical bursts. The power-control settings can be loaded into the memory, e.g., using a suitable calibration method configured to determine a respective nearly optimal coherent gain for receiving data from each of the remote optical transmitters.

公开(公告)号：US20190074908A1

公开(公告)日：2019-03-07

申请号：US15696939

申请日：2017-09-06

Applicant: Nokia Solutions and Networks OY

Inventor： Sian Chong Lee ,  Vincent Houtsma ,  Doutje van Veen ,  Chen Zhu ,  Noriaki Kaneda ,  Michael Eggleston

IPC: H04B10/61 ,  G06F11/14

Abstract: A coherent optical receiver having an analog electrical circuit connected to combine the outputs of multiple photodetectors to generate an electrical output signal from which the data encoded in a received modulated optical signal can be recovered in a robust and straightforward manner. In an example embodiment, the analog electrical circuit includes one or more transimpedance amplifiers connected between the photodetectors and the receiver's output port. The coherent optical receiver may include a dual-polarization optical hybrid coupled to eight photodiodes to enable polarization-insensitive detection of the received modulated optical signal. The signal processing implemented in the analog electrical circuit advantageously enables the use of relatively inexpensive local-oscillator sources that may have relaxed specifications with respect to linewidth and wavelength stability. Different embodiments of the analog electrical circuit can be used to enable the receiver to receive amplitude- and intensity-encoded modulated optical signals.

公开(公告)号：US20190253152A1

公开(公告)日：2019-08-15

申请号：US15896783

申请日：2018-02-14

Applicant: Nokia Solutions and Networks OY

Inventor： Vincent Houtsma ,  Doutje van Veen

IPC: H04B10/61 ,  H04B10/54 ,  H04L7/00

CPC classification number: H04B10/616 ,  H04B10/5167 ,  H04B10/541 ,  H04B10/612 ,  H04B10/69 ,  H04J14/0282 ,  H04L7/0075

Abstract: A PON having an OLT configured to send downlink transmissions to ONUs using amplitude modulation and two symbol rates. An example ONU includes a clock-recovery circuit capable of continuous clock extraction from the received variable-rate modulated optical signal. The continuous clock extraction can be achieved, e.g., by (i) configuring the photodetector to convert the higher-rate portions of the received optical signal into transformed electrical waveforms while converting the lower-rate portions thereof into similar electrical waveforms and (ii) configuring the clock-recovery circuit to phase-align the clock signal with signal transitions in the resulting sequence of transformed and similar electrical waveforms. An ONU configured to operate in this manner can advantageously stay locked to the received data signal during transmissions at both symbol rates, without the need to reacquire the clock signal at each rate change and/or at the beginning of each packet intended for the host ONU.

公开(公告)号：US20190238235A1

公开(公告)日：2019-08-01

申请号：US15885385

申请日：2018-01-31

Applicant: Nokia Solutions and Networks OY

Inventor： Vincent Houtsma ,  Doutje van Veen

IPC: H04B10/64 ,  H04B10/079 ,  H04B10/572 ,  H04J14/08

CPC classification number: H04B10/64 ,  H04B10/0795 ,  H04B10/572 ,  H04J14/08

Abstract: A passive optical network having an optical-signal monitor configured to monitor carrier-wavelength drifts during optical bursts transmitted between the optical line terminal and optical network units thereof. In an example embodiment, the optical-signal monitor uses heterodyne beating between two differently delayed portions of an optical burst to generate an estimate of the carrier-wavelength drift during that optical burst. The passive optical network may also include an electronic controller configured to use the estimates generated by the optical-signal monitor to make configuration changes at the optical network units and/or implement other control measures directed at reducing to an acceptable level the amounts of carrier-wavelength drift during the optical bursts and/or mitigating some adverse effects thereof.