Probabilistic constellation shaping across time and frequency

Patent metadata

Field	Value
Publication number	US-10587358-B1
Application number	US-201916289429-A
Country	US
Kind code	B1
Filing date	Feb 28, 2019
Priority date	Feb 28, 2019
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

An optical transmitter is operative to generate, from a plurality of encoded client bits, a set of symbols exhibiting non-uniform visitation probabilities in at least one dimension, to encode the set of symbols across a plurality of frequency division multiplexing (FDM) subcarriers, and to transmit an optical signal comprising the plurality of FDM subcarriers across which the set of symbols is encoded. An optical receiver is operative to decode a set of symbol estimates from a plurality of FDM subcarriers, the symbol estimates comprising estimates of symbols exhibiting non-uniform visitation probabilities in at least one dimension, and to recover client bits from the set of symbol estimates.

First claim

What is claimed is:

1. An optical transmitter comprising:
a processor; and
a memory storing computer-executable instructions which, when executed by the processor, cause the optical transmitter
to generate, from a plurality of encoded client bits, a set of symbols exhibiting non-uniform visitation probabilities in at least one dimension;
to encode the set of symbols across a plurality of frequency division multiplexing (FDM) subcarriers, wherein different subsets of the set of symbols are encoded on different FDM subcarriers using a permutation function available at the optical transmitter; and
to transmit an optical signal comprising the plurality of FDM subcarriers across which the set of symbols is encoded.

2. The optical transmitter as claimed in claim 1 , wherein at least one of the different subsets comprises consecutive symbols within the set of symbols.

3. The optical transmitter as claimed in claim 1 , wherein at least one of the different subsets comprises non-consecutive symbols within the set of symbols.

4. The optical transmitter as claimed in claim 1 , wherein the permutation function is programmed based on one or more properties of an optical communication link over which the optical signal is transmitted.

5. The optical transmitter as claimed in claim 1 , wherein the permutation function is programmed to provide different capacities on different FDM subcarriers.

6. The optical transmitter as claimed in claim 1 , wherein the computer-executable instructions, when executed by the processor, further cause the optical transmitter:
to generate the encoded client bits using a plurality of programmable look-up tables (LUTs) available at the optical transmitter.

7. The optical transmitter as claimed in claim 6 , wherein the plurality of LUTs are programmed based on one or more properties of an optical communication link over which the optical signal is transmitted.

8. An optical receiver configured to receive an optical signal over an optical communication link established between the optical receiver and an optical transmitter, wherein the received optical signal comprises a plurality of frequency division multiplexing (FDM) subcarriers, the optical receiver comprising:
a processor; and
a memory storing computer-executable instructions which, when executed by the processor, cause the optical receiver
to decode a set of symbol estimates from the plurality of FDM subcarriers, the symbol estimates comprising estimates of symbols exhibiting non-uniform visitation probabilities in at least one dimension, wherein different subsets of the symbol estimates are decoded from different FDM subcarriers using an inverse permutation function available at the optical receiver; and
to recover a plurality of client bits from the set of symbol estimates.

9. The optical receiver as claimed in claim 8 , wherein at least one of the different subsets comprises consecutive symbol estimates of the set of symbol estimates.

10. The optical receiver as claimed in claim 8 , wherein at least one of the different subsets comprises non-consecutive symbol estimates of the set of symbol estimates.

11. The optical receiver as claimed in claim 8 , wherein the computer-executable instructions, when executed by the processor, further cause the optical receiver:
to recover the plurality of client bits using a plurality of look-up tables (LUTs) available at the optical receiver.

12. The optical receiver as claimed in claim 8 , wherein the inverse permutation function is programmed based on one or more properties of the optical communication link.

13. The optical receiver as claimed in claim 8 , wherein the inverse permutation function is programmed to achieve different capacities on different FDM subcarriers.

14. The optical receiver as claimed in claim 11 , wherein the plurality of LUTs are programmed based on one or more properties of the optical communication link.

15. A method performed at an optical transmitter, the method comprising:
generating, from a plurality of encoded client bits, a set of symbols exhibiting non-uniform visitation probabilities in at least one dimension;
encoding the set of symbols across a plurality of frequency division multiplexing (FDM) subcarriers, wherein different subsets of the set of symbols are encoded on different FDM subcarriers using a permutation function available at the optical transmitter; and
transmitting an optical signal comprising the plurality of FDM subcarriers across which the set of symbols is encoded.

16. The method as claimed in claim 15 , wherein at least one of the different subsets comprises consecutive symbols of the set of symbols.

17. The method as claimed in claim 15 , wherein at least one of the different subsets comprises non-consecutive symbols of the set of symbols.

18. The method as claimed in claim 15 , wherein the permutation function is programmed based on one or more properties of an optical communication link over which the optical signal is transmitted.

19. The method as claimed in claim 15 , further comprising
generating the encoded client bits using a plurality of look-up tables (LUTs) available at the optical transmitter.

20. The method as claimed in claim 19 , wherein the plurality of LUTs are programmed based on one or more properties of an optical communication link over which the optical signal is transmitted.

Assignees

• Ebrahimzad Hamid
• Reimer Michael Andrew
• Ciena Corp

Inventors

• Ebrahimzad Hamid
• Reimer Michael Andrew

Classifications

• H04L1/0071

  Use of interleaving (interleaving per se H03M13/27) · CPC title

• H04L1/0065

  Serial concatenated codes · CPC title

• H04L1/0058

  Block-coded modulation · CPC title

• H04L1/0042

  Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape (H04L1/0067 takes precedence) · CPC title

• H04L1/0047

  Decoding adapted to other signal detection operation (in conjunction with sequence estimation or equalization H04L25/03286) · CPC title