Two Year Post Doc - Information Technology
calendar_month 05 Sep 2014, 00:00
Multi level coherent optical communication systems are under research with the aim of allowing 10-100 Tb/s transmission capacity over thousands of kilometers of fiber distances. These high constellation systems are mostly coherent systems with semiconductor lasers as transmitter and local oscillator and may use Raman type optical amplification.

The use of wavelength division multiplexed coherent systems is a viable way of increasing the capacity over one transmission fiber to the 100 Tb/s level. As such the systems are subject to influence of (laser) phase noise, intensity noise, additive noise, fiber dispersion and non-linearities, channel cross talk and various imperfections in the practical system realization.

It is imperative to choose system designs that minimize the noise influence and the impact of non-linearities and imperfections especially concerning phase noise and equalization enhanced phase noise for long range system which will be the main subject of investigation in the Post Doc work. Here, the digital signal processing (DSP) configuration in the system transmitter and receiver is important.


The project will develop and investigate theoretically, by simulations and experimentally new methods for constructing communications systems for long range transmission (>1000 km transmission range) with very high capacity. The work will be performed within the EU Marie Curie project ICONE which starts February 1, 2014 and has a duration of 4 years. The work will be in close collaboration with one PhD student at Acreo - Swedish ICT and 2 PhD students from Royal Institute of Technology (KTH) in Stockholm. Topics for study includes:
  • Ways of incorporating features like chromatic dispersion, fiber non-linearities, Raman amplification, and decide which implementations give the best phase noise tolerance.
  • Mitigation of component imperfections in system context.
  • Modulation techniques that are interesting are coherent n-level Phase Shift Keying (PSK) and Quadrature Amplitude Modulated (QAM) systems as well OFDM systems.
The Post Doc research will be based on numerical simulations (i.e. using tools like MATLAB, VPITtransmission Maker etc.) as well as on experimental verifications in the lab at high transmission speeds in the order of 100 GS/s.