Cycle slip reduction in coherent optical communications

US8886058B2 · kind B2 · utility

Assignee

• Cisco Technology, Inc. · US

Inventors

• Jonas Geyer · Seukendorf, DE
• Andreas Bisplinghoff · Forchheim, DE
• Theodor Kupfer · Feucht, DE

Key dates

• Filing date: Jun 4, 2012
• Grant date: Nov 11, 2014
• Expiry date: May 18, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B10/6165
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

Carrier phase estimation techniques are provided for processing a received optical signal having a carrier modulated according to a modulation scheme. First and second carrier phase estimation operations are performed on a digital signal derived from an optical carrier obtained from the received optical signal using coherent optical reception. The first carrier phase estimation operation tracks relatively fast phase variations of the optical carrier of the received optical signal to produce a first carrier phase estimation and the second carrier phase estimation operation tracks relatively slow phase variations of the optical carrier of the received optical signal to produce a second carrier phase estimation. A difference between the first and second carrier phase estimations is computed. Occurrence of a cycle slip is determined when the difference is greater than a threshold. A correction is applied to the first carrier phase estimation when the low pass filtered difference exceeds the threshold.