Studentische Arbeiten

Titel: Compensation of IQ-imbalance in a coherent optical OFDM system
  • Forschungsarbeit
Status: abgeschlossen


Orthogonal Frequency Division Multiplexing (OFDM) is today's prominent multicarrier modulation technique. It is adopted in standards such as LTE and WiFi due to its various advantages (enabling optimum and adaptive modulation format etc.). To meet the ever increasing data demand in optical backbone networks, coherent optical OFDM (COOFDM) is considered as a promising technology.


In order to achieve higher data rate (100 Gbit/s and beyond), signal impairments such as IQ-imbalance has to be compensated at the receiver.

The thesis can be accomplished either in German or English.


The tasks of this thesis involve:

  • studying the effect of IQ-imbalance (IQ-modulater at transmitter and Hybrid at receiver) in COOFDM system with the considerarion of fiber dispersion.
  • implementation of existing algorithm to estimate and compensate IQ-imbalance.
  • extension of simulation chain in C++
  • propose new algorithm for further improvement of signal quality (OSNR: optical SNR).


  • build COOFDM system in C++
  • Extending INÜ-Simulator
  • Proposing and developing algorithm
  • basics of digital signal processing