Data synchronization in optical networks and devices
AssigneeInfinera Corporation
InventorsMehdi Torbatian, Yuliang Gao, Ahmed Morra, Han Henry Sun, Yeongho Park
Life of this patent
Estimating the term…
Abstract
Joint estimation of the framer index and the frequency offset in an optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. By identifying the beginning of the header portion of a data frame, the receiver can then process data received from the transmitter in a manner synchronous to the manner in which the data was transmitted by the transmitter.
Claims21
An apparatus, comprising:
- an analog to digital conversion circuitry operable to receive electrical signals indicative of data carried by optical subcarriers and to provide a digital output;
- and
- a digital signal processor operable to:
- receive the digital output from the analog to digital conversion circuitry;
- determine an amount of chromatic dispersion associated with the optical subcarriers;
- and
- determine a framer index for the digital output based on the amount of chromatic dispersion associated with the optical subcarriers, the framer index being indicative of a location of a frame header in the digital output.
A receiver operable to communicate with a transmitting device over an optical network, the receiver comprising:
- an optics circuit configured to receive an electrical signal comprising optical subcarriers. each of the optical subcarriers comprising a data frame that comprises (i) a frame header comprising framer symbols and a first set of pilot symbols. and (ii) a payload comprising payload symbols and a second set of pilot symbols;
- and
- a digital signal processor operable to:
- determine an amount of chromatic dispersion associated with the optical subcarriers;
- and
- determine a framer index for the optical subcarriers based on the amount of chromatic dispersion associated with the optical subcarriers, the framer index being indicative of a location of the frame header in the data frame.
An apparatus, comprising:
- a polarization beam splitter operable to receive a signal comprising optical subcarriers from a fiber optic cable, each of the optical subcarriers comprising a data frame that comprises (i) a frame header comprising framer symbols and a first set of pilot symbols, and (ii) a payload comprising payload symbols and a second set of pilot symbols, wherein the polarization beam splitter is operable to separate the received signal into at least two polarization components;
- a laser operable to output a light signal;
- a first mixer operable to receive the light signal and a first component of the two polarization components, and to generate a first received component;
- a second mixer operable to receive the light signal and a second component of the two polarization components, and to generate a second received component;
- analog to digital conversion circuitry operable to receive and digitize the first received component and the second received component;
- and
- a processor operable to:
- receive the digitized first received component and the digitized second received component;
- determine an amount of chromatic dispersion associated with the optical subcarriers based on the digitized first received component and the digitized second received component;
- and
- determine a framer index for the optical subcarriers based on the amount of chromatic dispersion associated with the optical subcarriers, the framer index being indicative of a location of the frame header in the data frame.
Dependencies are inferred from the claim text.