Signal framing in a coherent optical receiver

摘要

A method and system for a estimating a most likely location of a periodic SYNC burst within an optical signal received through an optical communications system. A cross-correlation is calculated between a multi-bit digital signal derived from the optical signal and a known symbol sequence of the SYNC burst. The cross-correlation is processed in at least one sub-block to identify a candidate sub-block in which the SYNC burst is most likely located. The candidate sub-block is then further analyzed to estimate a location of the SYCN burst.

主权项

1. A method of estimating a location of a periodic SYNC burst within an optical signal received by a receiver through an optical communications system, the method comprising steps of:
a processor of the receiver calculating a cross-correlation between a multi-bit digital signal corresponding to the received optical signal and a known pattern corresponding to the SYNC burst; a framer processing samples of the cross-correlation to identify a candidate sub-block within which the SYNC burst is most likely located, wherein the candidate sub-block comprises a respective plurality of samples of the cross-correlation spanning more samples of the cross-correlation than the SYNC burst and less than a SYNC burst period; and the framer further processing samples of the cross-correlation within the candidate sub-block to identify the most likely location of the SYNC burst within the candidate sub-block.