About Me

Scientist & PhD Candidate — Fraunhofer HHI, Berlin

Professional Profile

I am a Scientist at the Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute (HHI), Berlin, within the Department of Photonic Networks and Systems, where I have been working since July 2021. In parallel, I am pursuing a PhD (Dr.-Ing.) at Technische Universität Berlin (TUB) under the working title “Investigating Adaptive Baseband Techniques for Converged Optical / THz Wireless Links.”

My research focuses on high-capacity Terahertz (THz) wireless communications and their integration into next-generation 6G photonic network infrastructures. I develop advanced Digital Signal Processing (DSP) algorithms for rate-adaptive THz links and conduct experimental characterisation of photonic transmitter components — including PIN photodiode and WR3-coupled transmitter configurations — for probabilistically shaped, high-speed THz wireless transmission beyond 100 Gbit/s. I am also actively exploring neural-network-based approaches to mitigate transceiver nonlinearities in THz systems.

Alongside my research role, I have served as a lecturer for Information and Communication programmes at Berlin universities, covering topics at the intersection of communications engineering and signal processing.

In-Ho Baek

Education

PhD — Electrical Engineering / Information Technology

Technische Universität Berlin (TUB), Berlin — 2026
Working title: Investigating Adaptive Baseband Techniques for Converged Optical / THz Wireless Links
Desired degree: Dr.-Ing.

M.Sc. — Electrical Engineering / Information Technology

Karlsruhe Institute of Technology (KIT), Karlsruhe — 2021
Focal points: Communication Engineering & Optical Communications
Master Thesis (at IPQ, KIT): Data-Aided Carrier Phase Recovery Algorithms for Coherent Optical Communication Systems

Exchange Programme — Electrical Engineering & Philosophy

Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea — 2018–2019
Courses: Radar Systems Engineering • MIMO Wireless Communications • Philosophy of Science
Supported by the Baden-Württemberg Scholarship 2018

B.Sc. — Electrical / Information Engineering

Karlsruhe Institute of Technology (KIT), Karlsruhe — 2018
Bachelor Thesis (at IMS, KIT): Investigation of the Timing Jitter of Superconducting Single Photon Detectors with Varying Meander Shapes

Professional Experience

Scientist — Fraunhofer Heinrich Hertz Institute (HHI), Berlin

July 2021 – present
Department of Photonic Networks and Systems
Research in optical and THz communications, including:

  • Advanced DSP development for rate-adaptive THz wireless communications
  • DSP on chip for high-speed coherent 800G ASICs
  • Device and experimental setup characterisation
  • Project management and scientific collaboration

Lecturer — HTW Berlin University of Applied Sciences (HTW Berlin)

October 2025 – March 2026
B.Sc. programme: Information and Communication Technology
Preparation and delivery of lectures, exercises, and assessments covering:

  • Fundamentals of telecommunications and communication systems
  • Digital signal processing and modulation schemes
  • Introduction to wireless and optical transmission systems

Lecturer — Berlin University of Applied Sciences and Technology (BHT Berlin)

October 2022 – March 2024
M.Sc. programme: Information and Communication Technology
Design and delivery of advanced graduate-level lectures and exercises covering:

  • Advanced communications engineering and system design
  • Optical and wireless transmission technologies
  • Channel coding, adaptive modulation, and probabilistic shaping concepts

Master Thesis — Institute of Photonics and Quantum Electronics (IPQ), KIT

October 2020 – April 2021
Data-Aided Carrier Phase Recovery Algorithms for Coherent Optical Communication Systems

Publications

First Author

  1. In-Ho Baek, J. Honecker, M. Bittiehn, R. Elschner, C. Schubert, R. Freund, “Experimental Demonstration of Neural-Network Based Transceiver Nonlinearity Mitigation for Probabilistically Shaped Photonic THz Wireless Transmission,” IEEE Photonics Technology Letters (PTL). [Submitted & In Review]
  2. In-Ho Baek, O. Stiewe, R. Elschner, M. Rösch, A. Tessmann, M. Nölle, L. Molle, C. Schubert, R. Freund, “Record 221 Gb/s Dual Polarization THz Wireless Transmission Over 500 m Using PCS-64QAM at 300 GHz,” Opto-Electronics and Communications Conference (OECC). [Submitted & In Review]
  3. In-Ho Baek, O. Stiewe, J. Gläsel, S. Nellen, G. Schwanke, T. T. Tran, R. Elschner, C. Schubert, R. B. Kohlhaas, P. Runge, M. Schell, R. Freund, “Experimental Characterization of Photodiode Transmitters for Probabilistically Shaped High-Speed THz Wireless Transmission,” Journal of Lightwave Technology, 2025.
  4. IH Baek, O. Stiewe, J. Gläsel, M. F. Ulukan, A. Schindler, F. Ganzer, T. T. Tran, “Experimental Characterization of a WR3-Coupled Photodiode Transmitter for High-Speed Terahertz Wireless Communication,” 2024 International Topical Meeting on Microwave Photonics, 2024.
  5. IH Baek, O. Stiewe, S. Nellen, G. Schwanke, R. Elschner, C. Schubert, “32 GBd, 109 Gbit/s Probabilistically Shaped THz Wireless Transmission using PIN-PD Based Photonic Upconversion,” IET Conference Proceedings CP839, pp. 1302–1305, 2023.
  6. IH Baek, F. Bart, R. Elschner, F. Meier, D. Hellmann, A. Maassen, C. Schubert, “Time Adaptive Probabilistic Shaping for Combined Optical/THz Links,” Photonic Networks; 23rd ITG-Symposium, pp. 1–8, 2022.

Co-Author

  1. R. Elschner, F. Bart, F. Meier, O. Stiewe, In-Ho Baek, S. Schütze, A. Maaßen, K. Das, R. B. Kohlhaas, S. Nellen, M. Deumer, T. Merkle, A. Tessmann, M. Rösch, C. Schubert, R. Freund, M. Schell, “Analysis of Weather-Related Link Availabilities for Fiber-Integrated THz-Wireless Transmission Systems,” Journal of Lightwave Technology, 2025.
  2. C. Schubert, R. Elschner, O. Stiewe, IH Baek, S. Schütze, A. Maaßen, K. Das, R. B. Kohlhaas, S. Nellen, M. Deumer, T. Merkle, A. Tessmann, M. Rösch, F. Meier, F. Bart, R. Freund, M. Schell, “High-Capacity THz Wireless Transmission Supporting Future 6G Optical Networks,” Optical Fiber Communication Conference (OFC), M3D.1, 2025.
  3. C. Schmidt-Langhorst, J. Pfeiffer, R. Elschner, R. Emmerich, F. Chowanek, IH Baek, R. F. H. Fischer, C. Schubert, “Experimental Investigation of Information Bit Scrambling for Physical-Layer Security in Coherent Fiber-Optic Systems,” Photonic Networks; 23rd ITG-Symposium, pp. 1–6, 2022.

Full list on Google Scholar  •  IEEE Xplore Profile

Technical Skills

  • Research Areas: Terahertz (THz) wireless communications, probabilistic constellation shaping (PCS), advanced digital signal processing, photonic upconversion, free-space and fiber-integrated optical communications
  • Technologies: High-speed THz transmission systems (WR-3 band), PIN photodiode transmitters, WR3-coupled transmitters, coherent optical ASICs (800G), quadrature amplitude modulation (QAM)
  • Engineering Tools: MATLAB (simulation & DSP), experimental optical/THz testbeds, oscilloscopes and spectrum analysers, signal generators
  • General: Electrical & electronics engineering, communication system design, experimental characterisation, project management

Languages

  • German — Native
  • Korean (한국어) — Mother tongue
  • English — Fluent (spoken and written)

Contact

Fraunhofer Institute for Telecommunications — Heinrich Hertz Institute (HHI)
Department of Photonic Networks and Systems, Berlin, Germany

Email: in-ho.baek@proton.me
LinkedIn: linkedin.com/in/in-ho-baek
Google Scholar: Scholar Profile
IEEE Xplore: IEEE Author Profile