APPARATUSES AND METHODS FOR DIGITAL SUBCARRIER PARAMETER MODIFICATIONS FOR OPTICAL COMMUNICATION NETWORKS

• US 20190319713A1
• Filed: 04/15/2019
• Published: 10/17/2019
• Est. Priority Date: 04/13/2018
• Status: Active Grant

• Current Assignee: Infinera Corp.
• Original Assignee: Infinera Corp.
• Inventors: Hand, Steven Joseph, Awadala, Ahmed, Perez, Luis A., Dominic, Vincent G., Wu, Kuang-Tsan
• Granted Patent: US 11,368,228 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04B 10/564 Power control
• CPC Class Codes: H04B 10/616 Details of the electronic signal processing in coherent optical receivers
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end

Abstract

Optical network systems are disclosed, including systems having transmitters with a digital signal processor comprising forward error correction circuitry that provides encoded first electrical signals based on input data; and power adjusting circuitry that receives second electrical signals indicative of the first electrical signals, the power adjusting circuitry supplying third electrical signals, wherein each of the third electrical signals is indicative of an optical power level of a corresponding to one of a plurality of optical subcarriers output from an optical transmitter.

Claims

1. A digital signal processor, comprising:

forward error correction circuitry that provides encoded first electrical signals based on input data; and

power adjusting circuitry that receives second electrical signals indicative of the first electrical signals, the power adjusting circuitry supplying third electrical signals, wherein each of the third electrical signals corresponds to an optical power level of a corresponding to one of a plurality of optical subcarriers output from an optical transmitter.

2. The digital signal processor of claim 1, wherein each of the third electrical signals has an associated one of a plurality of bandwidths, each of which corresponding to a spectral width of a respective one of the plurality of optical subcarriers.

3. The digital signal processor of claim 2, further comprising a plurality of pulse shape filters corresponding to each of the third electrical signals, the plurality of pulse shape filters configured to shape the associated one of the plurality of bandwidths of the third electrical signals, each of which corresponding to a spectral width of a respective one of the plurality of optical subcarriers.

4. The digital signal processor of claim 3, wherein each of the plurality of pulse shape filters is adjustable based on one or more control signal such that the shape of the plurality of bandwidths of the third electrical signals is adjustable.

5. The digital signal processor of claim 1, wherein the power adjusting circuitry is configured to adjust an electrical power level of one or more of the third electrical signals based at least in part on one or more characteristics of associated ones of transmission paths of corresponding optical subcarriers through an optical network.

6. The digital signal processor of claim 5, wherein the characteristics of the associated ones of transmission paths include one or more of:

a presence of one or more power splitter configured to divide the optical subcarrier;

length of the transmission paths;

a presence of one or more filter; and

a presence of one or more combiner configured to combine the optical subcarrier.

7. The digital signal processor of claim 1, wherein the power adjusting circuitry comprises a plurality of digital multipliers corresponding to a plurality of independent data streams.

8. The digital signal processor of claim 7, wherein the plurality of digital multipliers is adjustable based on one or more control signal such that power adjustment of each of the third electrical signals is configurable.

9. The digital signal processor of claim 8, wherein the power adjusting circuitry is adjustable based on one or more fourth electrical signals provided by a receiver that detects one or more of the plurality of optical subcarriers output from the optical transmitter.

10. The digital signal processor of claim 9, wherein the one or more fourth electrical signals is based on an optical power level of the one or more of the plurality of optical subcarriers previously detected by the receiver.

11. The digital signal processor of claim 9, wherein the one or more fourth electrical signals is based on a target optical power level of the one or more of the plurality of optical subcarriers at the receiver.

12. The digital signal processor of claim 9, wherein the one or more fourth electrical signals are associated with a feedback optical signal sent from the receiver to the optical transmitter.

13. The digital signal processor of claim 1, wherein a first one of the plurality of optical subcarriers carries first data with a first symbol rate and a second one of the plurality of optical subcarriers carries second data with a second symbol rate different than the first symbol rate.

14. The digital signal processor of claim 1, wherein a first one of the plurality of optical subcarriers has a first data capacity, and a second one of the plurality of optical subcarriers has a second data capacity that is the same as the first data capacity.

15. The digital signal processor of claim 1, wherein a first one of the plurality of optical subcarriers carries first data with a first data rate and a second one of the plurality of optical subcarriers carries second data with a second data rate different than the first data rate.

16. The digital signal processor of claim 1, wherein each of the plurality of optical subcarriers has a corresponding frequency, and having a first spacing between adjacent first and second frequencies, and having a second spacing different than the first spacing between adjacent third and fourth frequencies.

17. The digital signal processor of claim 1, wherein a first bandwidth of a first one of the plurality of optical subcarriers is wider than a second bandwidth of a second one of the plurality of optical subcarriers.

18. The digital signal processor of claim 1, wherein each of the plurality of optical subcarriers is modulated in accordance with the same modulation format.

19. The digital signal processor of claim 1, wherein a first one of the plurality of optical subcarriers is modulated in accordance with a first modulation format and a second one of the plurality of optical subcarriers is modulated in accordance with a second modulation format different than the first modulation format.

20. A node comprising:

an optical transmitter comprising a digital signal processor, comprising;

forward error correction circuitry that provides encoded first electrical signals based on input data; and

power adjusting circuitry that receives second electrical signals indicative of the first electrical signals, the power adjusting circuitry supplying third electrical signals, wherein each of the third electrical signals corresponds to an optical power level of a corresponding one of a plurality of optical subcarriers output from the optical transmitter; and

a control circuit that receives fourth electrical signals indicative of received power level of one or more of the plurality of optical subcarriers, provided by a receiver that detects one or more of the plurality of optical subcarriers output from the optical transmitter, whereby the control circuit adjusts the power adjusting circuitry based on the received fourth electrical signals.

21. The node of claim 20, further comprising:

a demultiplexer that filters an optical feedback signal provided by the receiver on an Optical Service Channel; and

a photodiode that coverts the optical feedback signal from the demultiplexer into the fourth electrical signals and forwards the fourth electrical signals to the control circuit.

22. The node of claim 20, further comprising:

a filter that filters an optical sideband signal provided by the receiver on a Control Channel having a lower frequency than the frequency of the plurality of optical subcarriers to generate the fourth electrical signals.

23. The node of claim 20, wherein the fourth electrical signals are generated from an optical feedback signal from the receiver, the optical feedback signal carrying a frame, the frame having a header that includes data, and wherein the optical power levels of the optical subcarriers are based on the data.

24. A transmitter, comprising:

a digital signal processor receiving a plurality of independent data streams, the digital signal processor supplying outputs based on the plurality of independent data streams, the outputs including a first digital subcarrier having a first frequency bandwidth and a second digital subcarrier having a second frequency bandwidth different than the first frequency bandwidth;

one or more digital-to-analog converter configured to convert the outputs of the digital signal processor to voltage signal outputs;

a laser configured to output an optical light beam; and

a modulator configured to modulate the optical light beam, based on the voltage signal outputs, to output a modulated optical signal including a plurality of optical subcarriers based on the outputs of the digital signal processor, wherein a first one of the plurality of optical subcarriers carries data indicative of a first one of the plurality of independent data streams, and a second one of the plurality of optical subcarriers carries data indicative of a second one of the plurality of independent data streams, wherein the first one of the plurality of optical subcarriers has a first optical bandwidth and the second one of the plurality of optical subcarriers has a second optical bandwidth different than the first optical bandwidth, and the first one of the plurality of optical subcarriers has a first level of optical power and the second one of the plurality of optical subcarriers has a second level of optical power different than the first level of optical power.

25. The transmitter of claim 24, wherein the digital signal processor comprises a plurality of digital multipliers corresponding to the plurality of independent data streams, the plurality of digital multipliers supplying electrical signals such that the power levels of the optical subcarriers are based on the electrical signals output from the plurality of digital multipliers.

26. The transmitter of claim 25, wherein the plurality of digital multipliers is adjustable based on one or more control signal such that power adjustment is configurable for any of the first and second digital subcarrier.

27. The transmitter of claim 26, wherein a third one of the plurality of optical subcarriers has a third optical bandwidth different than the first optical bandwidth, wherein the third one of the plurality of optical subcarriers has a third level of optical power different than the first level of optical power, wherein the first level of optical power is greater than the second and third levels of optical power, and wherein the first optical bandwidth is in between the second optical bandwidth and the third optical bandwidth.

28. The transmitter of claim 25, wherein the digital signal processor comprises a plurality of pulse shape filters corresponding to the plurality of independent data streams, the plurality of pulse shape filters configured to shape the first and second frequency bandwidths of the first and second digital subcarriers.

29. The transmitter of claim 28, wherein the plurality of pulse shape filters is adjustable based on one or more control signal such that the shape of the frequency bandwidths of the first and second digital subcarriers is adjustable.

30. An optical network system, comprising:

a hub, comprising;

a transmitter, comprising;

a digital signal processor receiving a plurality of independent data streams, the digital signal processor supplying outputs based on the plurality of independent data streams, the outputs including a first digital subcarrier having a first frequency bandwidth and a second digital subcarrier having a second frequency bandwidth different than the first frequency bandwidth;

one or more digital-to-analog converter configured to convert the outputs of the digital signal processor to voltage signal outputs;

a laser configured to output an optical light beam; and

a modulator configured to modulate the optical light beam, based on the voltage signal outputs, to output a modulated optical signal including a plurality of optical subcarriers based on the outputs of the digital signal processor, wherein a first one of the plurality of optical subcarriers carries data indicative of a first one of the plurality of independent data streams, and a second one of the plurality of optical subcarriers carries data indicative of a second one of the plurality of independent data streams, wherein the first one of the plurality of optical subcarriers has a first optical bandwidth and the second one of the plurality of optical subcarriers has a second optical bandwidth different than the first optical bandwidth, and the first one of the plurality of optical subcarriers has a first level of optical power and the second one of the plurality of optical subcarriers has a second level of optical power different than the first level of power;

a first edge node comprising a receiver configured to receive one or more of the plurality of optical subcarriers;

a second edge node comprising a receiver configured to receive one or more of the plurality of optical subcarriers;

a first transmission path between the hub and the first edge node; and

a second transmission path between the hub and the second edge node, wherein the second transmission path differs from the first transmission path.

31. The optical network system of claim 30, wherein the first level of power of the first optical subcarrier and the second level of power of the second optical subcarrier are based at least in part on one or more characteristics of at least one of the first transmission path and the second transmission path.

32. The optical network system of claim 30, wherein the digital signal processor comprises a plurality of digital multipliers corresponding to the plurality of independent data streams, the plurality of digital multipliers supplying electrical signals such that the optical power levels of the optical subcarriers are based on the electrical signals output from the plurality of digital multipliers.

33. The optical network system of claim 32, wherein the plurality of digital multipliers are configured to control power gain of the electrical signals and corresponding optical subcarriers based at least in part on one or more characteristics of at least one of the first transmission path and the second transmission path.

34. The optical network system of claim 33, wherein the characteristics of at least one of the first transmission path and the second transmission path include a presence of one or more splitter configured to divide the modulated optical signal into two parts;

length of the first and second transmission paths; and

a presence of one or more combiner configured to combine the modulated optical signal.

35. The optical network system of claim 32, wherein the second transmission path differs from the first transmission path in that a greater amount of optical power is needed to transmit one or more of the plurality of optical subcarriers through the second transmission path than the first transmission path.

36. The optical network system of claim 35, wherein the receiver of the first edge node is configured to receive the first one of the plurality of optical subcarriers, the receiver of the second edge node is configured to receive the second one of the plurality of optical subcarriers, and the plurality of digital multipliers are configured to provide a first power increase to the first optical subcarrier and to provide a second power increase to the second optical subcarrier, the second power increase larger than the first power increase.

37. An optical network system, comprising:

two or more edge nodes, each edge node comprising;

a transmitter, comprising;

a digital signal processor receiving a plurality of independent data streams, the digital signal processor supplying outputs based on the plurality of independent data streams, the outputs including a first digital subcarrier having a first frequency bandwidth and a second digital subcarrier having a second frequency bandwidth different than the first frequency bandwidth;

one or more digital-to-analog converter configured to convert the outputs of the digital signal processor to voltage signal outputs;

a laser configured to output an optical light beam; and

a modulator configured to modulate the optical light beam, based on the voltage signal outputs, to output a modulated optical signal including a plurality of optical subcarriers based on the outputs of the digital signal processor, wherein a first one of the plurality of optical subcarriers carries data indicative of a first one of the plurality of independent data streams, and a second one of the plurality of optical subcarriers carries data indicative of a second one of the plurality of independent data streams, wherein the first one of the plurality of optical subcarriers has a first optical bandwidth and the second one of the plurality of optical subcarriers has a second optical bandwidth different than the first optical bandwidth, and the first one of the plurality of optical subcarriers has a first level of optical power and the second one of the plurality of optical subcarriers has a second level of optical power different than the first level of optical power;

a hub comprising;

 

a receiver configured to receive one or more of the plurality of optical subcarriers; and

 

a transmitter;

a first transmission path between a first one of the two or more edge nodes and the hub; and

a second transmission path between a second one of the two or more edge nodes and the hub, wherein the second transmission path differs from the first transmission path.

38. The optical network system of claim 37, wherein the first level of optical power of the first optical subcarrier and the second level of optical power of the second optical subcarrier are based at least in part on one or more characteristics of at least one of the first transmission path and the second transmission path.

39. The optical network system of claim 37, wherein the digital signal processor comprises a plurality of digital multipliers corresponding to the plurality of independent data streams, the plurality of digital multipliers configured to control power gain of the optical subcarriers.

40. The optical network system of claim 39, wherein the plurality of digital multipliers are configured to control power gain of the optical subcarriers based at least in part on one or more characteristics of at least one of the first transmission path and the second transmission path.

41. The optical network system of claim 37, wherein the hub is configured to transmit from the transmitter of the hub information indicative of one or more measurements of the one or more of the plurality of optical subcarriers to one or more of the two or more edge nodes, and wherein the edge nodes are configured to adjust one or more of the first level of optical power of the first optical subcarrier and the second level of optical power of the second optical subcarrier based on the transmitted information.

42. The optical network system of claim 41, wherein the information indicative of one or more measurements of the one or more of the plurality of optical subcarriers is associated with a feedback optical signal sent from the transmitter of the hub to the one or more edge node.

43. The optical network system of claim 42, wherein the feedback optical signal is transmitted on an Optical Service Channel.

44. The optical network system of claim 42, wherein the feedback optical signal is transmitted on a Control Channel having a lower frequency than the frequency of the plurality of optical subcarriers.

45. The optical network system of claim 42, wherein the feedback optical signal carries a frame, the frame having a header that includes data, and wherein the optical power levels of one or more of the plurality of the optical subcarriers are based on the data.