US 2010/0135655 A1 · Multichannel Polarization Control for Polarization Multiplexed Optical Transport Networks

Abstract

A system and method are provided for calibrating orthogonal polarity in a multichannel optical transport network (OTN) receiver. The method accepts a composite signal and separates the polarization of the signal into a pair of 2n-phase shift keying (2n-PSK) modulated input signals via Ix and Qx optical signal paths, where n≧1. Likewise, a pair of 2p-PSK modulated input signals are accepted via Iy and Qy optical signal paths where p≧1. Polarization-adjusted I′x, Q′x, I′y, and Q′y signals are generated. An average magnitude is compared to either 2×the absolute magnitude of (I′x and Q′x), or 2×the absolute magnitude of (I′y and Q′y). The average magnitude value can be used that is either 2×(a predetermined peak signal amplitude), or the sum of the absolute magnitudes of (I′x and Q′x) and (I′y and Q′y). The polarization-adjusted I′x, Q′x, I′y, and Q′y signals are modified until the magnitude comparison is about zero.

Claims16

Dependent claims

A method for calibrating orthogonal polarity in a multichannel optical transport network (OTN) receiver, the method comprising:

accepting a pair of 2n-phase shift keying (2n-PSK) modulated input signals via Ix and Qx optical signal paths, where n≧1;
accepting a pair of 2p-PSK modulated input signals via Iy and Qy optical signal paths where p≧1;
generating polarization-adjusted I′x, Q′x, I′y, and Q′y signals;
comparing an average magnitude to a magnitude selected from a group consisting of 2×the absolute magnitude of (I′x and Q′x) and 2×the absolute magnitude of (I′y and Q′y);
and,
modifying the polarization-adjusted I′x, Q′x, I′y, and Q′y signals until the magnitude comparison is about zero.

3 more elements

A system for calibrating orthogonal polarity in a multichannel optical transport network (OTN) receiver, the system comprising:

a polarization adjustment circuit (PAC) having an input to accept a pair of 2n-phase shift keying (2n-PSK) modulated input signals via Ix and Qx optical signal paths, where n≧1, an input to accept a pair of 2p-PSK modulated input signals via Iy and Qy optical signal paths where p≧1, and an output to supply polarization-adjusted I′x, Q′x, I′y, and Q′y signals;
a magnitude measurement circuit (MMC) having an input to accept the polarization-adjusted I′x, Q′x, I′y, and Q′y signals, the MMC comparing an average magnitude to a magnitude selected from a group consisting of 2×the absolute magnitude of (I′x and Q′x) and 2×the absolute magnitude of (I′y and Q′y), and supplying a magnitude comparison measurement signal;
and,
wherein the PAC accepts the magnitude comparison measurement signal and modifies the polarization-adjusted I′x, Q′x, I′y, and Q′y signals until the magnitude comparison measurement is about zero.

1 more element

Dependencies are inferred from the claim text.

Multichannel Polarization Control for Polarization Multiplexed Optical Transport Networks

Life of this patent

Multichannel Polarization Control for Polarization Multiplexed Optical Transport Networks

Life of this patent

Abstract

Claims16