CHANNEL CARRYING MULTIPLE DIGITAL SUBCARRIERS

• US 20140092924A1
• Filed: 09/28/2012
• Published: 04/03/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Infinera Corp.
• Original Assignee: Infinera Corp.
• Inventors: Sun, Han, Wu, Yuejian, McNicol, John, Krause, David James, Wu, Kuang-Tsan
• Granted Patent: US 10,014,975 B2
• Time in Patent Office: Days
• US Class Current: 370/536
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04J 14/0305 in end terminals

Abstract

An optical system includes a transmitter module and/or a receiver module. The transmitter module is configured to receive input data, map the input data to a set of subcarriers associated with an optical communication channel, independently apply spectral shaping to each of the subcarriers, generate input values based on the spectral shaping of each of the subcarriers, generate voltage signals based on the input values, modulate light based on the voltage signals to generate an output optical signal that includes the subcarriers, and output the output optical signal. The receiver module is configured to receive the output optical signal, convert the output optical signal to a set of voltage signals, generate digital samples based on the set of voltage signals, independently process the digital samples for each of the subcarriers, map the processed digital samples to produce output data, and output the output data.

Claims

1. An optical system, comprising:

a transmitter module comprising;

a processor configured to;

receive input data,

map the input data to a plurality of subcarriers associated with an optical communication channel,

independently apply spectral shaping to each of the plurality of subcarriers, and

generate input values based on the spectral shaping of each of the plurality of subcarriers;

a digital-to-analog converter configured to;

receive the input values from the processor, and

generate voltage signals based on the input values;

a laser configured to output light; and

a modulator configured to;

receive the light from the laser and the voltage signals from the digital-to-analog converter,

modulate the light based on the voltage signals to generate an output optical signal that includes the plurality of subcarriers, and

output the output optical signal.

2. The optical system of claim 1, where the processor includes:

a demultiplexer configured to;

receive the input data, and

separate the input data for the plurality of subcarriers;

a plurality of transmitters, each of the plurality of transmitters corresponding to a respective one of the plurality of subcarriers,

each of the plurality of transmitters being configured to;

receive the input data for the respective one of the plurality of subcarriers, and

process the input data, for the respective one of the plurality of subcarriers, to produce one or more of the input values; and

a multiplexer configured to;

receive the one or more of the input values from each of the plurality of transmitters,

combine the one or more of the input values to produce a string of input values, and

output the string of input values to the digital-to-analog converter.

3. The optical system of claim 2, where forward error correction coding is applied to the input data to produce forward error correction encoded data, and

where the demultiplexer, when separating the input data for the plurality of subcarriers, is configured to systematically interleave the forward error correction encoded data over the plurality of subcarriers.

4. The optical system of claim 2, where at least one of the demultiplexer, one or more of the plurality of transmitters, or the multiplexer is configured to apply timing skew to each of the plurality of subcarriers.

5. The optical system of claim 1, where the processor is configured to apply separate forward error correction coding to each of the plurality of subcarriers.

6. The optical system of claim 1, where:

the processor and the digital-to-analog converter are implemented on one or more application specific integrated circuits,

the laser and the modulator are implemented on one or more photonic integrated circuits, or

the processor, the digital-to-analog converter, the laser, and the modulator are implemented on a single integrated device.

7. The optical system of claim 1, where the modulator is a first modulator and the output optical signal is a first output optical signal,

where the transmitter module further comprises:

a second modulator configured to produce a second output optical signal,

the first output optical signal having a first polarization, and

the second output optical signal having a second polarization, the second polarization being substantially orthogonal with respect to the first polarization.

8. The optical system of claim 1, further comprising:

a receiver module comprising;

a detector configured to;

receive the output optical signal, and

convert the output optical signal to a set of voltage signals;

an analog-to-digital converter configured to;

receive the set of voltage signals from the detector, and

generate digital samples based on the set of voltage signals; and

a receiver processor configured to;

receive the digital samples from the analog-to-digital converter,

process the digital samples to produce output data, and

output the output data.

9. The optical system of claim 8, where the receiver module further comprises:

a local oscillator configured to generate an optical signal; and

a mixer configured to;

receive the optical signal from the local oscillator and the output optical signal,

combine the optical signal and the output optical signal to generate a resulting optical signal, and

output the resulting optical signal to the detector.

10. The optical system of claim 1, further comprising:

a receiver module comprising;

a demultiplexer configured to;

receive the output optical signal, and

separate the output optical signal into a plurality of optical signals, each of the plurality of optical signals corresponding to one or more of the plurality of subcarriers; and

a plurality of receiver components, each of the plurality of receiver components being configured to;

receive a respective one of the plurality of optical signals, and

process the respective one of the plurality of optical signals to obtain output data associated with the corresponding one or more of the plurality of sub carriers.

11. An optical system, comprising:

a receiver module comprising;

a detector configured to;

receive a particular optical signal that includes a plurality of subcarriers associated with an optical communication channel, and

convert the particular optical signal to a set of voltage signals;

an analog-to-digital converter configured to;

receive the set of voltage signals from the detector, and

generate digital samples based on the set of voltage signals; and

a processor configured to;

receive the digital samples from the analog-to-digital converter,

independently process the digital samples for each of the plurality of subcarriers,

map the processed digital samples to produce output data, and

output the output data.

12. The optical system of claim 11, where the receiver module further comprises:

a local oscillator configured to generate an optical signal; and

a mixer configured to;

receive the optical signal from the local oscillator and the particular optical signal,

combine the optical signal and the particular optical signal to generate a resulting optical signal, and

output the resulting optical signal to the detector.

13. The optical system of claim 11, where the detector, when converting the particular optical signal to the set of voltage signals, is configured to detect an entire spectrum, associated with the optical communication channel, including the plurality of subcarriers.

14. The optical system of claim 11, where the processor includes:

a demultiplexer configured to;

receive the digital samples, and

separate the digital samples, each of the digital samples corresponding to one or more of the plurality of subcarriers;

a plurality of receivers, each of the plurality of receivers being configured to;

receive the digital samples for the corresponding one or more of the plurality of subcarriers, and

process the digital samples, for the corresponding one or more of the plurality of subcarriers, to produce the output data; and

a multiplexer configured to;

receive the output data from each of the plurality of receivers,

combine the output data to produce a stream of output data, and

output the stream of output data.

15. The optical system of claim 14, where each of the plurality of receivers, when processing the digital samples, is configured to perform a function to correct for polarization mode dispersion or a function relating to carrier recovery.

16. The optical system of claim 14, where at least one of one or more of the plurality of receivers or the multiplexer is further configured to apply timing skew to the output data corresponding to each of the plurality of subcarriers.

17. The optical system of claim 14, where forward error correction is to be applied to remove errors from the output data, the forward error correction being applied by one or more of the plurality of receivers or after combining the output data by the multiplexer.

18. The optical system of claim 11, where the particular optical signal includes forward error correction encoded data that is systematically interleaved over the plurality of subcarriers, and

where the processor is further configured to systematically de-interleave the forward error correction encoded data from the plurality of subcarriers.

19. The optical system of claim 11, further comprising:

a transmitter module comprising;

a transmitter processor configured to;

receive input data,

map the input data to the plurality of subcarriers associated with the optical communication channel, and

generate input values based on mapping the input data to the plurality of subcarriers;

a digital-to-analog converter configured to;

receive the input values from the transmitter processor, and

generate voltage signals based on the input values;

a laser configured to output light; and

a modulator configured to;

receive the light from the laser and the voltage signals from the digital-to-analog converter,

modulate the light based on the voltage signals to generate the particular optical signal that includes the plurality of subcarriers, and

output the particular optical signal.

20. The optical system of claim 19, where the transmitter processor includes:

a demultiplexer configured to;

receive the input data, and

separate the input data for the plurality of subcarriers;

a plurality of transmitters, each of the plurality of transmitters corresponding to a respective one of the plurality of subcarriers,

each of the plurality of transmitters being configured to;

receive the input data for the respective one of the plurality of subcarriers, and

process the input data, for the respective one of the plurality of subcarriers, to produce one or more of the input values; and

a multiplexer configured to;

receive the one or more of the input values from each of the plurality of transmitters,

combine the one or more of the input values to produce a string of input values, and

output the string of input values to the digital-to-analog converter.

21. An optical system, comprising:

a receiver module comprising;

a demultiplexer configured to;

receive a particular optical signal that includes a plurality of subcarriers associated with an optical communication channel, and

separate the particular optical signal into a plurality of optical signals, each of the plurality of optical signals corresponding to one or more of the plurality of subcarriers; and

a plurality of receiver components, one of the plurality of receiver components including;

a detector configured to;

receive one of the plurality of optical signals, and

convert the one of the plurality of optical signals to a set of voltage signals;

an analog-to-digital converter configured to;

receive the set of voltage signals from the detector, and

generate digital samples based on the set of voltage signals; and

a processor configured to;

receive the digital samples from the analog-to-digital converter,

independently process the digital samples for each of the one or more of the plurality of subcarriers,

map the processed digital samples to produce output data, and

output the output data.

22. The optical system of claim 21, where the one of the plurality of receiver components further includes:

a local oscillator configured to generate an optical signal; and

a mixer configured to;

receive the optical signal from the local oscillator and the one of the plurality of optical signals,

combine the optical signal and the one of the plurality of optical signals to generate a resulting optical signal, and

output the resulting optical signal to the detector.

23. The optical system of claim 21, further comprising:

a transmitter module comprising;

a transmitter processor configured to;

receive input data,

map the input data to the plurality of subcarriers associated with the optical communication channel, and

generate input values based on mapping the input data to the plurality of subcarriers;

a digital-to-analog converter configured to;

receive the input values from the transmitter processor, and

generate voltage signals based on the input values;

a laser configured to output light; and

a modulator configured to;

receive the light from the laser and the voltage signals from the digital-to-analog converter,

modulate the light based on the voltage signals to generate the particular optical signal that includes the plurality of subcarriers, and

output the particular optical signal.

24. The optical system of claim 23, where the transmitter processor includes:

a demultiplexer configured to;

receive the input data, and

separate the input data for the plurality of subcarriers;

a plurality of transmitters, each of the plurality of transmitters corresponding to a respective one of the plurality of subcarriers,

each of the plurality of transmitters being configured to;

receive the input data for the respective one of the plurality of subcarriers, and

process the input data, for the respective one of the plurality of subcarriers, to produce one or more of the input values; and

a multiplexer configured to;

receive the one or more of the input values from each of the plurality of transmitters,

combine the one or more of the input values to produce a string of input values, and

output the string of input values to the digital-to-analog converter.

25. The optical system of claim 23, where the transmitter module is implemented on at least one of one or more application specific integrated circuits or one or more photonic integrated circuits.

26. The optical system of claim 21, where the receiver module is implemented on at least one of one or more application specific integrated circuits or one or more photonic integrated circuits.

27. An optical system, comprising:

a transmitter module configured to;

receive input data,

map the input data to a plurality of subcarriers associated with an optical communication channel,

independently apply spectral shaping to each of the plurality of subcarriers,

generate input values based on the spectral shaping of each of the plurality of subcarriers,

generate voltage signals based on the input values,

modulate light based on the voltage signals to generate an output optical signal that includes the plurality of subcarriers, and

output the output optical signal; and

a receiver module configured to;

receive the output optical signal,

convert the output optical signal to a set of voltage signals,

generate digital samples based on the set of voltage signals,

independently process the digital samples for each of the plurality of subcarriers,

map the processed digital samples to produce output data, and

output the output data.

28. The optical system of claim 27, where the transmitter module includes:

a processor configured to;

map the input data to the plurality of subcarriers, and

generate the input values;

a digital-to-analog converter configured to generate the voltage signals based on the input values;

a laser configured to output the light; and

a modulator configured to modulate the light based on the voltage signals to generate the output optical signal.

29. The optical system of claim 27, where the receiver module includes:

a detector configured to convert the output optical signal to the set of voltage signals;

an analog-to-digital converter configured to generate the digital samples based on the set of voltage signals; and

a processor configured to process the digital samples to produce the output data.

30. The optical system of claim 27, where the transmitter module is implemented on at least one of one or more application specific integrated circuits or one or more photonic integrated circuits, and

the receiver module is implemented on at least one of one or more application specific integrated circuits or one or more photonic integrated circuits.

31. The optical system of claim 27, where the transmitter module is one of a plurality of transmitter modules, the plurality of transmitter modules being implemented on at least one of one or more application specific integrated circuits or one or more photonic integrated circuits, or

the receiver module is one of a plurality of receiver modules, the plurality of receiver modules being implemented on at least one of one or more application specific integrated circuits or one or more photonic integrated circuits.