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.
Claims20
An apparatus, comprising:
- an analog to digital conversion circuitry operable to receive data and to output digitized data corresponding to the received data;
- and
- a digital signal processor operable to receive the digitized data from the analog to digital conversion circuitry, the digital signal processor comprising:
- a quantizer circuit operable to quantize the digitized data according to a determined number of quantization levels;
- and
- a framer circuit operable to synchronize the quantized digitized data received from the quantizer circuit with data transmission from a transmitter, the quantized digitized data comprising:
- a frame header comprising framer symbols and a first set of pilot symbols, and
- a payload comprising payload symbols and a second set of pilot symbols.
A receiver operable to communicate over an optical network, the receiver comprising:
- an optics circuit configured to receive electrical signals indicative of data carried by subcarrier signals, each of the subcarrier signals comprising a data frame that comprises:
- a frame header comprising framer symbols and a first set of pilot symbols;
- and
- a payload comprising payload symbols and a second set of pilot symbols;
- a quantizer circuit coupled to the optics circuit and operable to receive the subcarrier signals from the optics circuit and to quantize one or more of symbols in the subcarrier signals according to a determined number of quantization levels;
- and
- a framer circuit coupled to the quantizer circuit and operable to synchronize the quantized one or more of symbols received from the quantizer circuit with data transmission from a transmitter.
An apparatus comprising:
- an analog to digital conversion circuitry operable to receive data comprising symbols and to output digitized symbols corresponding to the received data;
- an inverse fast Fourier transform (IFFT) circuit operable to perform an inverse fast Fourier transform on the digitized symbols;
- a quantizer circuit coupled to the IFFT circuit and operable to quantize the digitized symbols received from the IFFT circuit according to a determined number of quantization levels;
- and
- a framer circuit operable to perform cross correlation of a set of descrambled symbols and a first subset of the quantized symbols and to estimate a framer index associated with the received data based on an outcome of the cross correlation, the framer index being indicative of a location of a frame header in the received data.
Dependencies are inferred from the claim text.