IP Library Granted Patent US 9,450,715
Granted Patent B2
US 9,450,715 · App. 14/808,062 · Granted Sep 20, 2016

Method and system for modulation-independent carrier phase recovery

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Quick Facts
Patent No.
US 9,450,715
App. No.
14/808,062
Granted
Sep 20, 2016
Kind
B2
Abstract

A system for carrier phase recovery, including a receiver for receiving one or more frames of L symbols. A phase estimator performs carrier phase estimation for the received frames of L symbols, and the resulting carrier phase estimates are stored in a non-transitory computer-readable storage medium. One or more rotators de-rotates the received frames of L symbols by one or more of the carrier phase estimates, and a data processor calculates a sum of the outputs of the L de-rotated signals raised to an n th power, and determines a real part of the sum. A minimum determination device determines a minimum of the real part of the sum with respect to the carrier phase estimates, and phase unwrapping and multiplier removal is performed if a minimum has been determined.

Claims (35)

1. A computer implemented method for carrier phase recovery, comprising:

receiving, using a receiver, one or more frames of L symbols;

performing, using a phase estimator, carrier phase estimation for the one or more frames of L symbols and storing resulting carrier phase estimates in a non-transitory computer-readable storage medium;

de-rotating, using a rotator, the one or more frames of L symbols by one or more of the resulting carrier phase estimates;

calculating, using a data processor, a sum of the outputs of L de-rotated signals raised to an n th power, where n is an integer, and determining a real part of the sum;

determining, using a minimum determination device, a minimum of the real part of the sum with respect to the carrier phase estimates, wherein phase unwrapping and multiplier removal are performed if the minimum of the real part has been determined.

2. The method of claim 1 , wherein the resulting carrier phase estimates are stored in a Lookup Table (LUT).

3. The method of claim 1 , wherein the method for carrier phase recovery employs a feed-forward structure, the feed-forward structure enabling parallel implementation of high-speed coherent receivers without performance degradation.

4. The method of claim 1 , wherein the method for carrier phase recovery is modulation-independent.

5. The method of claim 1 , wherein the phase unwrapping unwraps a current phase estimate based on a previous phase estimate.

6. The method of claim 1 , wherein a frame length of the frame of L symbols is dependent on a magnitude of laser linewidth.

7. The method of claim 1 , wherein the carrier phase estimates include a range from −π/4 to π/4.

8. The method of claim 7 , wherein the method for carrier phase recovery recovers a signal carrier phase without prior knowledge of modulation formats.

9. A system for carrier phase recovery, comprising:

a receiver for receiving one or more frames of L symbols;

a phase estimator for performing carrier phase estimation for the one or more frames of L symbols, resulting carrier phase estimates being stored in a non-transitory computer-readable storage medium;

one or more rotators for de-rotating the one or more frames of L symbols by one or more of the resulting carrier phase estimates;

a data processor for calculating a sum of the outputs of L de-rotated signals raised to an n th power, where n is an integer, and for determining a real part of the sum;

a minimum determination device for determining a minimum of the real part of the sum with respect to the resulting carrier phase estimates, wherein phase unwrapping and multiplier removal are performed if the minimum of the real part has been determined.

10. The system of claim 9 , wherein the resulting carrier phase estimates are stored in a Lookup Table (LUT).

11. The system of claim 9 , further comprising parallel implementation of high-speed coherent receivers without performance degradation.

12. The system of claim 9 , wherein the system for carrier phase recovery is modulation-independent.

13. The system of claim 9 , wherein the phase unwrapper unwraps a current phase estimate based on a previous phase estimate.

14. The system of claim 9 , wherein a frame length of the frame of L symbols is dependent on a magnitude of laser linewidth.

15. The system of claim 9 , wherein the carrier phase estimates include a range from −π/4 to π/4.

16. The system of claim 9 , wherein the system for carrier phase recovery recovers a signal carrier phase without prior knowledge of modulation formats.

17. A non-transitory computer readable storage medium comprising a computer readable program, wherein the computer readable program when executed on a computer causes the computer to perform the steps of:

receiving one or more frames of L symbols using a receiver;

performing carrier phase estimation for the one or more frames of L symbols using a phase estimator, and storing resulting carrier phase estimates in a non-transitory computer-readable storage medium;

de-rotating, using a rotator, the one or more frames of L symbols by one or more of the resulting carrier phase estimates;

calculating, using a data processor, a sum of the outputs of L de-rotated signals raised to an n th power, where n is an integer, and determining a real part of the sum; and

determining, using a minimum determination device, a minimum of the real part of the sum with respect to the resulting carrier phase estimates, wherein phase unwrapping and multiplier removal are performed if the minimum of the real part has been determined.

18. The computer readable storage medium of claim 17 , wherein the phase unwrapping unwraps a current phase estimate based on a previous phase estimate.

19. The computer readable storage medium of claim 17 , wherein a frame length of the frame of L symbols is dependent on a magnitude of laser linewidth.

20. The computer readable storage medium of claim 17 , wherein the carrier phase estimates include a range from −π/4 to π/4.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 15, 2016
From: NEC LABORATORIES AMERICA, INC.
To: NEC CORPORATION
Reel/Frame 039435/0820 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 24, 2015
From: INADA, YOSHIHISA
To: NEC CORPORATION
Reel/Frame 036170/0017 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 24, 2015
From: ZHANG, SHAOLIANG; YAMAN, FAITH
To: NEC LABORATORIES AMERICA, INC.
Reel/Frame 036177/0812 →