Thomas Wiegart received the B.Sc. degree (with distinction) and the M.Sc. degree (with high distinction) in electrical engineering from Technical University of Munich (TUM) in 2015 and 2018, respectively.
He is currently working towards the doctoral degree at the TUM Institute for Communications Engineering under the supervision of Prof. Gerhard Kramer. His research interests include information theory, channel coding, probabilistic shaping, and optical communications.
Mr. Wiegart was the recipient of the Walter Gademann Price in 2016 for his Bachelor thesis, and he received an Outstanding Teaching Assistant Award from the student representatives of the Department of Electrical and Computer Engineering, TUM in 2020.
- Nachrichtentechnik 1 (Digital Communications) [summer terms 2019, 2020, 2021]
- Basic Laboratory Course on Telecommunications [summer and winter terms 2018/19, 2019, 2019/20, 2020, 2020/21, 2021, 2021/22]
- Communications Laboratory [winter terms 2019/20, 2020/21, 2021/22]
- Machine Learning for Communications [winter term 2020/21]
Constellation Optimization for Fiber-Optic Links with Direct Detection
We investigate an extension of  to complex-valued constellations, as well as a general optimization of constellations, which work with .
 M. Secondini and E. Forestieri, “Direct detection of bipolar pulse amplitude modulation,” J. Lightw. Technol., vol. 38, no. 21, pp. 5981– 5990, 2020.
SDM for Fiber-Optic Links with Direct Detection
Two work is two-fold:
- Physically consistent modelling of space division multiplexing (SDM) over a short-reach multimode fiber, including direct detection (DD) per mode.
- a) Analysis of achievable rates, simple upper and lower bounds on capacity for SDM with DD.
- b) (MIMO) Equalization for SDM with DD.
Rates for Short-Reach Fiber-Optic Links with Direct Detection
The topic deals with maximizing the generalized mutual information (GMI) for short-reach fiber-optic links. In particular, we are interested in jointly optimizing transmit and receive filters.
Investigation of Improved Decoding for Polar Coded Shaping
channel coding, probabilistic shaping, polar coding
Probabilistic shaping combines forward error correction and distribution matching. It allows to send encoded information with non-uniform symbol distributions. These non-uniform symbol distributions are required to achieve optimal transmission rates. One way to implement probabilistic shaping is polar coding , in particular Honda-Yamamoto coding . For a more practical introduction to polar coding see .
The goal is to compare the performances of different encoding and decoding schemes for Honda-Yamamoto codes.
In this Forschungspraxis, the task is to investigate decoder performances for Honda-Yamamoto codes with different, structurally similar, decoders. The student will understand and implement successive-cancellation decoding  and successive-cancellation list decoding  for polar codes. Using these two decoders, one can directly construct encoders and decoders for Honda-Yamamoto codes for which we compare error correction capability and en-/decoding complexity under probabilistic shaping scenarios.
- Basics in Information Theory (entropy, mutual information, channel capacity)
- Basics in Channel Coding (goal of forward error correction, linear block codes, knowledge about soft decoding algorithms is helpful)
Linear Computation Coding
The students task is to understand and summarize , which is about a new method of calculating matrix-vector products in a fast way using coding theory.
Channel Coding, Information Theory
- Achievable Rates for Short-Reach Fiber-Optic Channels with Direct Detection. IEEE/OSA J. Lightw. Technol., 2022 mehr… Volltext ( DOI )
- Multilevel Binary Polar-Coded Modulation Achieving the Capacity of Asymmetric Channels. IEEE International Symposium on Information Theory (ISIT), 2022Espoo, Finland mehr…
- Invertible low-divergence coding. IEEE Transactions on Information Theory 68 (1), 2022, 178-192 mehr… Volltext ( DOI )
- PAM-6 Coded Modulation for IM/DD Channels with a Peak-Power Constraint. International Symposium on Topics in Coding (ISTC) 2021, 2021 mehr…
- Signalling for Fiber-Optic Channels with Direct Detection. Ferienakademie 2021: Advanced Topics in Information Theory and Communications, 2021 mehr…
- Asymmetric Signalling using Polar Codes. University of California, Los Angeles (UCLA), Communications Systems Laboratory, 2021 mehr…
- Probabilistically Shaped 4-PAM for Short-Reach IM/DD Links with a Peak Power Constraint. Journal of Lightwave Technology 39 (2), 2021 mehr… Volltext ( DOI )
- Recovering the Phase in DD Receivers with Oversampling: A Toy Example. Huawei Joint Lab Workshop, 2021 mehr…
- Research Activities at LNT. 2019 Workshop of the Centre of Excellence for Silicon Photonics for Optical Communications (SPOC), 2019 mehr…
- Shaping for Intensity Modulation with Direct Detection. 2019 Workshop on Coding, Cooperation, and Security in Modern Communication Networks (COCO), 2019 mehr…
- Shaping for Asymmetric Channels using Polar Codes. 2019 Munich Doctoral Seminar on Communications, 2019 mehr…
- Design of Polar Codes for Parallel Channels with an Average Power Constraint. IEEE International Symposium on Information Theory, 2019 mehr…
- Shaped On-Off Keying Using Polar Codes. IEEE Communication Letters 23 (11), 2019 mehr… Volltext ( DOI )
- Close-to-Optimal Partial Decode-and-Forward Rate in the MIMO Relay Channel via Convex Programming. 20th International ITG Workshop on Smart Antennas (WSA 2016), 2016 mehr…