Investigation and Real-Time FPGA Implementation of DSP Algorithms for Coherent Optical Data Transmission

by Filipp Gostner

Thursday Nov 5, 2026, 2:00 PM → 3:00 PM Europe/Berlin

Seminarraum EG (IPE)

Filip Gostner will present the results of his Bachelor thesis.

Abstract:
This thesis investigates real-time digital signal processing (DSP) for coherent optical dual polarization (DP) communication systems. The required DSP stages are reviewed, and selected implementations are evaluated with respect to their performance and suitability for real-time operation. The DSP is implemented on a field-programmable gate array (FPGA) platform and evaluated at line rates of 9.6 Gbit/s for DP-QPSK and 19.2 Gbit/s for DP-16-QAM. The evaluation comprises a noise-loading experiment, a recirculating loop experiment and a single polarization sub-THz communication system to assess the performance and portability of the implementation. In the noise-loading experiment, a gap of 1.5 to 2 dB to the theoretical limit for an additive white Gaussian noise (AWGN) channel is observed for QPSK, while a slightly higher penalty is observed for 16-QAM. In the recirculating loop, transmission distances exceeding 3500 km for QPSK and 1500 km for 16-QAM are achieved. The results demonstrate the feasibility of the implemented DSP for real-time coherent optical and wireless communication systems and provide insight into its performance under different transmission scenarios.