Aspects of Power Consumption in Coherent Fiber-Optical Communication Systems
Licentiate thesis, 2017

The power consumption of coherent fiber-optical communication systems is becoming increasingly important, for both environmental and economical reasons. The data traffic on the Internet is increasing at a faster pace than that at which optical network equipment is becoming more energy efficient, which means that the overall power consumption of the Internet is increasing. In addition, wasted energy leads to higher costs for network operators, through increased electricity expenses but also because the heat generated in the equipment limits how closely it can be packed. This thesis includes power consumption modelling, trade-off studies and investigations of novel schemes that may lead to an improved energy efficiency in future systems. In particular, the power consumption of optical amplifiers is modelled and connected to a performance model based on the Gaussian-noise model. Using these models, the trade-offs between amplifier power consumption and the choice of modulation format and forward-error-correction (FEC) scheme is studied. We find that 16-ary quadrature-amplitude modulation (16QAM) has a lower energy consumption per bit than quadrature phase-shift keying (QPSK) due to its higher spectral efficiency, and that using a shorter amplifier spacing to improve signal quality may be more energy efficient than using a powerful FEC. Furthermore, the power consumption for a coherent link with minimal digital signal processing (DSP) is studied. We find that when the DSP is minimized, it accounts for below 10% of the power consumption, which is dominated by the optical components. Finally, we demonstrate that the phase-coherence of optical frequency comb lines can be utilized to simplify the carrier-recovery by joint processing of multiple wavelength channels. We use the phase-drift from one wavelength channel to compensate the phase-drift of another one spaced up to 275GHz away with negligible penalty.

optical frequency comb

Fiber-optical communication

power consumption

carrier-recovery

Raman amplification

energy-efficiency

optical amplifier

digital signal processing

coherent detection

erbium-doped fiber amplifier

phase-tracking

A423 Kollektorn, Department of Microtechnology and Nanoscience (MC2), Kemivägen 9, Göteborg
Opponent: Darko Zibar, Technical University of Denmark, Denmark

Author

Lars Lundberg

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Power Consumption of a Minimal-DSP Coherent Link with a Polarization Multiplexed Pilot-Tone

42nd European Conference and Exhibition on Optical Communications, September 18-22, 2016, Düsseldorf,;(2016)

Paper in proceeding

Power Consumption Analysis of Hybrid EDFA/Raman Amplifiers in Long-Haul Transmission Systems

Journal of Lightwave Technology,;Vol. 35(2017)p. 2132-2142

Journal article

Lars Lundberg, Mikael Mazur, Abel Lorences-Riesgo, Magnus Karlsson and Peter A. Andrekson, Joint Carrier Recovery for DSP Complexity Reduction in Frequency Comb-Based Superchannel Transceivers

Areas of Advance

Information and Communication Technology

Subject Categories

Telecommunications

Communication Systems

Other Electrical Engineering, Electronic Engineering, Information Engineering

Technical report MC2 - Department of Microtechnology and Nanoscience, Chalmers University of Technology: 368

Publisher

Chalmers

A423 Kollektorn, Department of Microtechnology and Nanoscience (MC2), Kemivägen 9, Göteborg

Opponent: Darko Zibar, Technical University of Denmark, Denmark

More information

Created

8/15/2017