Ciena Corporation
Minimum variance carrier recovery with increased phase noise tolerance

Abstract:

A method of data symbol recovery in a coherent receiver of an optical communications system includes processing data symbol estimates detected from a received optical signal, and determining recovered symbol values from the processed data symbol estimates. The recovered symbol values belong to a symbol constellation having a predetermined asymmetry. Processing the data symbol estimates compensates phase noise that is greater than one decision region of the symbol constellation. A coherent receiver of an optical communications system includes a module configured to process data symbol estimates detected from a received optical signal and a decision circuit configured to determine recovered symbol values from the processed data symbol estimates. The recovered symbol values belong to a symbol constellation having a predetermined asymmetry. Processing the data symbol estimates compensates phase noise that is greater than one decision region of the symbol constellation.