TRANSPORT OF MULTIPLE ASYNCHRONOUS DATA STREAMS USING HIGHER ORDER MODULATION

摘要

Aspects of the invention provide transmitters and receivers for managing multiple optical signals. High order modulation, such as phase and/or amplitude modulation, is used to achieve multiple bits per symbol by transporting multiple asynchronous data streams in an optical transport system. One or more supplemental multiplexing techniques such as time division multiplexing, polarization multiplexing and sub-carrier multiplexing may be used in conjunction with the high order modulation processing. This may be done in various combinations to realize a highly spectrally efficient multi-data stream transport mechanism. The system receives a number of asynchronous signals which are unframed and synchronized, and then reframed and tagged prior to the high order modulation. Differential encoding may also be performed. Upon reception of the multiplexed optical signal, the receiver circuitry may employ either direct detection without a local oscillator or coherent detection with a local oscillator.

主权项

1. An optical transmitter, comprising:
a module configured to:
receive a plurality of frames obtained from a plurality of N asynchronous data streams, the plurality of frames having framing information of the asynchronous data streams removed,reframe the plurality of frames using a common clock as a synchronous reference to obtain a plurality of synchronized data streams, and tag one or more selected ones of the synchronized data streams with encoded information; and a modulator configured to perform 2N level optical modulation of the synchronized data streams, including the tagged synchronized data streams.