US 11,082,280 B2 · Mitigating optical modulator impairment for coherent optical communication systems

Abstract

System for adjusting a reference constellation for demodulating an optical signal include a coherent electro-optical receiver configured to convert a received optical signal to a plurality of electrical signals, an array of analog-to-digital convertors configured to digitize the plurality of electrical signals, and processor logic. The processor logic is configured to process the digitized plurality of electrical signals using a reference constellation to yield a plurality of decoded signals and a signal quality measurement. The reference constellation includes an inphase component equal to an ideal inphase component plus an inphase offset and a quadrature component equal to an ideal quadrature component plus a quadrature offset. The processor logic is configured to determine an optimal inphase offset and optimal quadrature offset. The processor logic is configured to update the reference constellation using the optimal inphase offset and the optimal quadrature offset.

Claims18

Dependent claims

A system for adjusting a reference constellation for demodulating an optical signal comprising:

one or more processors configured to:
process a digitized plurality of electrical signals using a reference constellation to yield a plurality of decoded signals and a signal quality measurement;
determine an inphase offset of the reference constellation by adjusting the inphase offset to a first threshold value of the signal quality measurement and keeping a quadrature offset of a reference constellation constant;
determine a quadrature offset of the reference constellation by adjusting the quadrature offset to a second threshold value of the signal quality measurement and keeping the inphase offset of the reference constellation constant;
and
update the reference constellation by setting the inphase offset to the determined inphase offset and the quadrature offset to the determined quadrature offset,
wherein the one or more processors include high-speed processor logic and low-speed processor logic, and
wherein the high-speed processor logic operates a frequencies above 1 gigabit per second, and the low-speed processing operates at frequencies below 10 megabits per second.

5 more elements

A method of adjusting a reference constellation for demodulating an optical signal comprising:

processing, using one or more processors, a digitized plurality of electrical signals using a reference constellation to yield a plurality of decoded signals and a signal quality measurement;
determining, using the one or more processors, an inphase offset of the reference constellation by adjusting the inphase offset to a first threshold value of the signal quality measurement and keeping a quadrature offset of a reference constellation constant;
determining, using the one or more processors, a quadrature offset of the reference constellation by adjusting the quadrature offset to a second threshold value of the signal quality measurement and keeping the inphase offset of the reference constellation constant;
and
updating, using the one or more processors, the reference constellation by setting the inphase offset to the determined inphase offset and the quadrature offset to the determined quadrature offset,
wherein the one or more processors include high-speed processor logic and low-speed processor logic, and
wherein the high-speed processor logic operates a frequencies above 1 gigabit per second, and the low-speed processing operates at frequencies below 10 megabits per second.

4 more elements

Dependencies are inferred from the claim text.

Mitigating optical modulator impairment for coherent optical communication systems

Life of this patent

Mitigating optical modulator impairment for coherent optical communication systems

Life of this patent

Abstract

Claims18