Patent ID: 8824501

Claim:
An apparatus comprising an optical receiver that comprises: a front-end circuit configured to convert an optical input signal into a corresponding plurality of digital electrical signals; and a processor configured to: process the plurality of digital electrical signals to generate a first set of complex values, each corresponding to a first bit-word, said first set of complex values including at least three complex values; sum the at least three complex values of the first set to generate a summed complex value; and map the summed complex value onto a constellation to determine the first bit-word; and wherein, in response to the optical input signal having at least a first optical variant, a second optical variant, and one or more additional optical variants, with each of said first, second, and one or more additional optical variants carrying the first bit-word, the processor is configured to include into the at least three complex values: at least one complex value that corresponds to the first optical variant; at least one complex value that corresponds to the second optical variant; and at least one complex value that corresponds to an additional optical variant.