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Coherent optical OFDM: theory and design
1ARC Special Research Centre for Ultra-Broadband Information Networks and National ICT Australia, Department of Electrical and Electronic Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia. w.shieh@ee.unimelb.edu.au
Optics Express
|June 11, 2008
Summary
Coherent optical Orthogonal Frequency Division Multiplexing (CO-OFDM) offers robust performance against dispersion. This study details CO-OFDM fundamentals, design, and digital signal processing for noise mitigation.
Area of Science:
- Optical communications engineering
- Digital signal processing
Background:
- Coherent optical Orthogonal Frequency Division Multiplexing (CO-OFDM) is a novel technology.
- Existing optical systems face challenges with chromatic dispersion and polarization mode dispersion.
Purpose of the Study:
- To review the theoretical underpinnings of CO-OFDM.
- To analyze CO-OFDM system designs and nonlinearity.
- To explore digital signal processing techniques for noise reduction.
Main Methods:
- Theoretical review of CO-OFDM fundamentals.
- Channel modeling using a 2x2 MIMO-OFDM representation.
- Nonlinearity analysis of RF-to-optical up-converters.
- Development of receiver-based digital signal processing algorithms.
Main Results:
- CO-OFDM demonstrates significant robustness against chromatic dispersion and polarization mode dispersion.
- Analysis of various CO-OFDM design choices and their nonlinear effects.
- Effective mitigation of self-phase-modulation and phase noise using digital signal processing.
Conclusions:
- CO-OFDM presents a promising solution for high-performance optical communication systems.
- Digital signal processing at the receiver is crucial for overcoming nonlinear impairments.
- The presented techniques are equivalent to midspan phase conjugation for noise mitigation.
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