Transmission and reception of duobinary multilevel pulse-amplitude-modulated optical signals using subsequence-based encoder

An optical communication system, comprising:

• a subsequence decomposer for decomposing compositions of input information bits into at least two input subsequences including a first of said input subsequences having a first level for a first of said compositions and a second level for all other said compositions, and a second of said input subsequences having said first level for a second of said compositions and said second level for all other said compositions;
• a subsequence composer for composing an encoded pulse amplitude modulation (PAM) signal from differently weighted output subsequences derived from said input subsequences, respectively;
• and
• a modulation subsystem including a driver for converting said PAM signal into a modulation drive signal and an optical signal generator for responding to said drive signal by issuing an optical electric field having field levels including one or more positive said field levels and one or more negative said field levels, a first of said positive field levels and a first of said negative field levels having mirror-image redundant representations of said first of said compositions of said input information bits.