Multilevel pulse position modulation for efficient fiber optic communication

A method for decreasing transmitted power in a channel of an optical fiber communication system while maintaining channel bandwidth, the method comprising the steps of:

• receiving one or more digital input signals, each having a data rate;
• creating a digital input word having n bits from the one or more digital input signals;
• converting the digital input word to a corresponding output symbol representing one of 2n distinct values, wherein the output symbol comprises a multilevel pulse position modulated symbol;
• and
• generating an output signal comprising the output symbol in a series of output symbols, wherein the output signal has an aggregate data rate substantially equal to a sum of the data rates of the digital input signals, and
• wherein a transmitted power of the output signal is less than half of another transmitted power for conveying the data using on-off modulation at the aggregate data rate.

A method for managing power for an optical communication channel,

• wherein the optical communication channel is compatible with transmitting an on-off modulated signal, comprising on-off modulated symbols, at a data rate and a transmitted power,
• the method comprising the steps of:
• receiving digital input signals, collectively providing at least the data rate;
• producing digital input words, each having n bits, in response to processing the received digital input signals;
• converting the digital input words into corresponding symbols, each representing one of 2n distinct values and each comprising a multilevel pulse position modulated symbol;
• and
• producing an output signal, comprising the corresponding symbols, for transmission over the optical communication channel,
• wherein the output signal provides at least the data rate at another transmitted power that is less than the transmitted power.