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US 8,942,573 B2Granted
Blind equalization algorithms for adaptive polarization recovery and PMD compensation
AssigneeAT&T Intellectual Property I, L.P.
InventorXiang Zhou
Life of this patent
Estimating the term…
Abstract
A device and method are disclosed for blind equalization of an optical signal to implement adaptive polarization recovery, Polarization Mode Dispersion (PMD) compensation, and residual Chromatic Dispersion (CD) compensation in a digital coherent optical communication system.
Claims20
A non-transitory computer readable medium storing computer program instructions, which, when executed on a processor, cause the processor to perform operations comprising:
- receiving an optical signal (Z);
- and
- calculating an error ε signal, representative of distortion in the optical signal (Z), by utilizing a plurality of reference circles cascaded relative to each other, wherein the error ε signal is defined by ε=ƒ2(ƒ1(|Z|, C1), C2), wherein each of the reference circles C1, C2 have different radii R1, R2, the reference circles C1, C2 defined by:
- C
- 1
- =
- R
-
-
- 1
- p
- +
- R
-
-
- 2
- p
- 2
- C
- 2
- =
- (
- R
-
-
- 1
- p
- -
- R
-
-
- 2
- p
- 2
- )
- q
- wherein p and q are selected order numbers,
- wherein ƒ1, ƒ2 are each two variable functions and C1, C2 are each constants, such that the two variable functions, ƒ1, ƒ2, and the constants, C1, C2, are determined to make ƒ2 (ƒ1(|Z|, C1), C2) approach zero for a quadrature amplitude modulation signal.
35 more elements
A method comprising:
- receiving an optical signal (Z);
- and
- calculating an error ε signal, representative of distortion in the optical signal (Z), by utilizing a plurality of reference circles cascaded relative to each other, wherein the error ε signal is defined by ε=ƒ2(ƒ1(|Z|, C1), C2), wherein each of the reference circles C1, C2 have different radii R1, R2, the reference circles C1, C2 defined by:
- C
- 1
- =
- R
-
-
- 1
- p
- +
- R
-
-
- 2
- p
- 2
- C
- 2
- =
- (
- R
-
-
- 1
- p
- -
- R
-
-
- 2
- p
- 2
- )
- q
- wherein p and q are selected order numbers,
- wherein ƒ1, ƒ2 are each two variable functions and C1, C2 are each constants, such that the two variable functions, ƒ1, ƒ2, and the constants, C1, C2, are determined to make ƒ2(ƒ1(|Z|, C1), C2) approach zero for a quadrature amplitude modulation signal.
35 more elements
An apparatus, comprising:
- a memory storing computer program instructions for compensating a received signal and adaptive polarization recovery;
- and
- a processor communicatively coupled to the memory, the processor to execute the computer program instructions, which, when executed on the processor, cause the processor to perform operations comprising:
- receiving an optical signal (Z);
- and
- calculating an error ε signal, representative of distortion in the optical signal (Z), by utilizing a plurality of reference circles cascaded relative to each other, wherein the errors signal is defined by ε=ƒ2(ƒ1(|Z|, C1), C2), wherein each of the reference circles C1, C2 have different radii R1, R2, the reference circles C1, C2 defined by:
- C
- 1
- =
- R
-
-
- 1
- p
- +
- R
-
-
- 2
- p
- 2
- C
- 2
- =
- (
- R
-
-
- 1
- p
- -
- R
-
-
- 2
- p
- 2
- )
- q
- wherein p and q are selected order numbers,
- wherein ƒ1, ƒ2 are each two variable functions and C1, C2 are each constants, such that the two variable functions, ƒ1, ƒ2, and the constants, C1, C2, are determined to make ƒ2(ƒ1(|Z|, C1), C2) approach zero for a quadrature amplitude modulation signal.
38 more elements
Dependencies are inferred from the claim text.