Demodulation of an optical carrier
US8200099B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 2010 |
| Grant date | Jun 12, 2012 |
| Priority date | — |
| Expiry date | Oct 4, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03343
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method of transmitting a plurality n data streams comprises modulating an optical carrier using differential M-ary phase shift key (DMPSK) signaling in which M=2n. Advantageously the method comprises using differential quaternary phase shift keying in which n=2. A particular advantage of the method of the present invention is that since the data is differentially encoded in the form of phase changes rather than absolute phase values this enables the modulated optical carrier to be demodulated using direct detection without requiring a phase-locked local optical oscillator. The invention is particularly applicable to WDM communication systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.