Infinera Corporation

Yeongho Park

Han Henry Sun

Mehdi Torbatian

Yuliang Gao

Ahmed Morra

Edward Everett Sprague

Prasad Paranjape

Arvinderpal S Wander

Mallikarjun Chillal

Michael Kutty K G

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.

Data synchronization in optical networks and devices

Optical transmitters and receivers for improving synchronization of data transmitted over an optical network are described. The receiver can perform non-linear filtering as part of framer index estimation operations to improve the synchronization. The receiver can determine estimated positions of framer indices in data frames received from the transmitter. Next, using a non-linear filter, the receiver can remove estimated positions that are likely erroneous or are greater than a threshold away from the median or mode estimated framer index position. By removing the likely erroneous estimated positions, the receiver can then determine the estimated position of a framer index position for multiple frames with greater confidence.

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 synchronize, with less error, the data transmitted by the transmitter and the data it received. To further improve the framer index estimation, a lock indicator signal can be generated to signal to other receiver components that the estimated framer indices are reliable. The receiver can determine frequency offset and additional framer index estimations with increased reliability when performed after the lock indicator signal is generated.

A client receive circuit receives client data from a network, decodes the client data and stores the client data within the memory. A frame transmit circuit is provided that includes a justification control logic and a framer and a justification control logic is provided that 1) determines each of a plurality of fill levels and 2) determines an average of the plurality of fill levels. The framer has circuitry to generate a wrapper including a justification opportunity having data based upon a difference between the average and a predetermined threshold.

Growing community of inventors

Palo Alto, CA, United States of America

Yeongho Park