Optical modulation schemes having reduced nonlinear optical transmission impairments

摘要

A method of transmitting a data signal using an optical transmitter of an optical communications system. The optical transmitter is configured to modulate an optical carrier in successive signalling intervals to generate an optical signal. A modulation scheme is provided which comprises a multi-dimensional symbol constellation. The modulation scheme is designed such that an average degree of polarization of a modulated optical signal output from the optical transmitter has a first value when averaged across a first signaling interval, and has a second value when averaged across more than one and fewer than 100 signaling intervals. The second value is less than 10 percent of the first value. During run-time, an encoder of the optical transmitter encoding a data signal to be transmitted as symbols of the constellation, and a modulator of the optical transmitter modulating available dimensions of the optical carrier in accordance with the symbols.

主权项

1. A method of transmitting a data signal using an optical transmitter of an optical communications system, the optical transmitter being configured to modulate an optical carrier in successive sets of signaling intervals to generate an optical signal, the method comprising:
an encoder of the optical transmitter encoding the data signal in accordance with a modulation scheme comprising a multi-dimensional symbol constellation configured such that a degree of polarization of a modulated optical signal output from the optical transmitter has a first value when averaged across a first signaling interval, and has a second value when averaged across a set of signaling intervals containing more than 1 and fewer than 100 signaling intervals and including the first signaling interval, wherein the second value is less than 10 percent of the first value.