Persönlicher Status und Werkzeuge

Open Theses

You may also contact one of our doctoral candidates directly, if you are interested in a Bachelor or Master thesis, a student job, an "Ingenieurspraxis" or a "Forschungspraxis". It often happens, that topics are being prepared which are not adverdised yet. It may also be possible to find a topic matching your specific interests.
Please include a curriculum vitae together with a list of attended courses when applying for a thesis.
If your "Ingenieurspraxis" is selected to be supervised by one of our professors, please hand in the documents to Doris Dorn (Room N2401).

Bachelor Theses

Communication over Unknown Channels
First, the student will build in Matlab a simple transmitter(Tx)/receiver(Rx) chain. The chain is tested over AWGN channel. Next, we modify the channel to a more complex one with additional (possibly unknown) parameters, e.g., Ryleigh, Rician, Phase-noise, or other standardized models. Now, the Rx has to be modified, i.e., it has to perform the channel estimation to decode the data. Different channel estimation/data processing strategies are evaluated to cope with more complex channels. The presented here work-flow is flexible and can be modified according to students interests/progress.
Supervisor: Marcin Pikus

LDPC Decoder implementation on FPGA
Feasible decoding complexity is a major criteria for any decoding algorithm. LDPC Codes have linear decoding complexity, which makes them interesting for various applications. The aim of this bachelor thesis is to implement one specific LDPC Code on hardware starting from a software implementation.
Week 1: get familiar with LDPC Codes
Week 2: implement LDPC decoder in software
Week 3-8: implement LDPC decoder on FPGA
Week 8-9: write your thesis

Requirements: some experience with FPGAs
Supervisor: Peihong Yuan, Patrick Schulte, Georg Böcherer

Bachelor or Master Theses

Error Correcting Codes for Insertion/Deletion Errors
The discussion of synchronization errors, like insertions and deletions of symbols into codewords goes back to the early 1960's. Still, little is known about these kinds of errors and basic questions, like the capacity of the binary deletion channel remain unsolved. This stems from the fact that errors in the insertion/deletion metric are fundamentally different from the well-researched substitution errors and conventional error correcting codes cannot be applied on these kinds of errors. Current research, and the topic of this Master thesis, is directed towards finding the minimum redundancy of such codes and developing constructions that can correct insertion and deletion errors.

Prerequisites: You should have good knowledge in linear Algebra and interest in channel coding.
Supervisor: Andreas Lenz

Master Theses

A Deterministic Approach to the Gaussian Multiple-Input Multiple-Output (MIMO) Broadcast Channel
Multi-user communication systems (such as wireless systems) are different than point to point channels in two key aspects; namely, the broadcast nature of transmissions (e.g., wireless transmissions can be picked up by any receiver in the vicinity of the transmitter) and the superposition (e.g., a wireless receiver picks up a linear combination of transmissions from all transmitters in its vicinity). Recently a deterministic approach to multi-user information theory has proved promising by achieving progress in some of the long-standing open problems by finding approximate solutions. The idea behind a deterministic approach, on a high level, is to focus on the interaction of signals rather than the background noise, through a simpler appropriate model; find exact solutions for the simpler model; and then translate the intuitions and techniques to new techniques and/or approximate solutions on noisy models.
The goal of thesis is to undertake a deterministic approach to Gaussian MIMO broadcast channels.
Prerequisite: Linear Algebra, Information Theory
Supervisor: Shirin Saeedi

Role of Feedback in Broadcasting
This project intends to investigate the role of feedback in broadcast channels. More information available upon request. Pre-requisite (at least one of the following):
Basic knowledge of Network Coding (see [2])
Basic knowledge of Algorithms
Basic knowledge of Information Theory
Supervisor: Shirin Saeedi

Code and Algorithm Design for Physical and Biometric Security

We are looking for motivated students to work on algorithm and code design for privacy and security applications. For realistic channel models, we want to implement a set of codes and algorithms to analyse their complexity, reliability, privacy, and secrecy performance.

Pre-requisites: Information theory and channel coding

Supervisor: Onur Günlü

Simulation of Improved Staircase Code Decoding

Staircase codes, as introduced in 2011 by Smith et. al. [1], are a hardware friendly code design for error correction in optical communication systems. However, the choices of parameters such as block size and code rate that achieve a desired output bit error rate are limited by the error floor of the decoder. A new and improved decoder has been devised [2], allowing for staircase codes with a scope of new parameters to be considered for optical communication. While estimations show the significant improvements, the high throughput required to simulate the error floor can, in software, only be achieved with an efficient and parallelisable implementation. The main goal of the thesis is the implementation and simulation of the new decoder in C in order to provide further evidence for the estimated performance.

Prerequisites: interest in channel coding, knowledge in C

[1] [2]

Supervisor: Lukas Holzbaur

Application of Machine Learning in Wireless Communications
See here thesis_TUM_ML.pdf.
Supervisor: Georg Böcherer, Prof. David Gesbert, Paul de Kerret

Fundamental Outerbounds of Wireless Communications with Imperfect Channel State Information at the Transmitter
See here thesis_TUM_IT.pdf.
Supervisor: Georg Böcherer, Prof. David Gesbert, Paul de Kerret

Generalized Concatenated Codes with BCH and Polar Codes

Polar Codes [1] are a class of channel codes that are proven to achieve the capacity of binary input discrete memoryless channels, asymptotically in the block length. Nevertheless, the performance for finite block lengths is not competitive with state-of-the-art channel codes like Turbo or LDPC codes.

In [2], outer cyclic redundancy check (CRC) codes and list decoding are used to improve the distance properties and the performance of polar codes. The main idea of generalized concatenated codes (GCC) [3] is to concatenate several inner and outer codes to improve the distance properties of the resulting overall code.

The goal of the thesis is to implement generalized concatenated coding schemes using Polar codes and other codes like BCH or CRC codes and to analyse and discuss the distance properties and the performance of the schemes.

Preliminaries: Channel coding and basic knowledge in Information Theory

[1] E. Arikan, "Channel Polarization: A Method for Constructing Capacity-Achieving Codes for Symmetric Binary-Input Memoryless Channels," in IEEE Transactions on Information Theory, vol. 55, no. 7, pp. 3051-3073, July 2009.
[2] I. Tal and A. Vardy, "List Decoding of Polar Codes," in IEEE Transactions on Information Theory, vol. 61, no. 5, pp. 2213-2226, May 2015.
[3] ZYABLOV, Victor; SHAVGULIDZE, Sergo; BOSSERT, Martin. An introduction to generalized concatenated codes. European Transactions on Telecommunications, 1999, 10. Jg., Nr. 6, S. 609-622.
Supervisor: Tobias Prinz, Antonia Wachter-Zeh

Post-Quantum Cryptography on Automotive Microcontroller
Public-key cryptography (PKC) is the foundation for establishing secure communication chan- nels between multiple parties. It is a critical piece of technology for highly interconnected networks and therefore vital for the automotive world. However, due to the fear of the immi- nent arrival of quantum computers, traditional PKC algorithms such as RSA and ECC, are beginning to be considered risky for implementations in secured devices. This is especially true for applications with long life-cycle, if the devices deployed in the field are hard to update. In fact, if capable quantum computers become available, cryptographic systems based on the inte- ger factorization problem and the (elliptic curve) discrete logarithm problem could be attacked in polynomial time due to the work of Shor [8]. As a reaction, the National Security Agency (NSA) announced the intention to transition towards quantum-resistant, i.e., post-quantum, cryptography for governmental usage in the foreseeable future. Concurrently, the National Institute of Standards and Technology (NIST) of the United States has already started mov- ing forward with efforts towards standardization. Beside PKC, also secret-key cryptography (SKC) is affected by the advent of quantum computers. Grover’s quantum algorithm [3] does speed up attacks and doubling the key size can effectively block these attacks. In a real-time and safety-critical environment like high-speed in-vehicle car networks doubling the key size leads to an increase of additional delays in processing of data due to elaborated symmetric en- /decryption and authentication techniques (currently a cipher-based message authentication code as proposed in [2] is used in Controller Area Network (CAN) in vehicle bus systems).

Scope of the Thesis
In this Master’s thesis we want to:
1. Identify, evaluate and implement post-quantum asymmetric PKC systems (as, e.g., [2, 4, 5, 6, 7]) for the automotive context on an Infineon Aurix-2G microcontroller.
2. Improve code-based post-quantum PKC systems w.r.t. a possible reduction of the key size and the speed and complexity of the en- and decryption algorithm (as, e.g., [6, 7, 9]).
3. Investigate mechanisms (in soft- and hardware) to support post-quantum PKC and SKC systems in automotive microcontrollers (e.g., extended key storage, hardware primitives).

[1] D. J. Bernstein, T. Lange, and C. Peters. “Attacking and Defending the McEliece Cryp- tosystem”. Ed. by J. Buchmann and J. Ding. Vol. 5299. Lecture Notes in Computer Science. Cited by 0139. Springer Berlin Heidelberg, 2008, pp. 31–46.
[2] M. J. Dworkin. SP 800-38B. Recommendation for Block Cipher Modes of Operation: The CMAC Mode for Authentication. Tech. rep. Gaithersburg, MD, United States: National Institute of Standards & Technology, 2005.
[3] L. K. Grover. “A fast quantum mechanical algorithm for database search”. arXiv:quant- ph/9605043 (1996). arXiv: quant-ph/9605043.
[4] J. Hoffstein, J. Pipher, and J. H. Silverman. “NTRU: A ring-based public key cryptosys- tem”. en. Algorithmic Number Theory. Ed. by J. P. Buhler. Lecture Notes in Computer Science. DOI: 10.1007/BFb0054868. Springer Berlin Heidelberg, June 1998, pp. 267–288.
[5] R. J. McEliece. “A Public-Key Cryptosystem Based On Algebraic Coding Theory”. Deep Space Network Progress Report 44 (Jan. 1978), pp. 114–116.
[6] R. Misoczki, J. P. Tillich, N. Sendrier, and P. S. L. M. Barreto. “MDPC-McEliece: New McEliece variants from Moderate Density Parity-Check codes”. 2013 IEEE International Symposium on Information Theory Proceedings (ISIT). July 2013, pp. 2069–2073. doi: 10.1109/ISIT.2013.6620590.
[7] N. Sendrier. “QC-MDPC-McEliece: A public-key code-based encryption scheme based on quasi-cyclic moderate density parity check codes”. en. Nov. 2014.
[8] P. W. Shor. “Polynomial-Time Algorithms for Prime Factorization and Discrete Loga- rithms on a Quantum Computer”. SIAM J. Comput. 26.5 (1997), pp. 1484–1509. doi: 10.1137/S0097539795293172.
[9] R. Zalman and A. Mayer. “A Secure but Still Safe and Low Cost Automotive Communi- cation Technique”. Proceedings of the 51st Annual Design Automation Conference. DAC ’14. New York, NY, USA: ACM, 2014, 43:1–43:5. doi: 10.1145/2593069.2603850.
Supervisor: Antonia Wachter-Zeh, Infineon Technologies (Laurent Heidt, Alexander Zeh)

Protected Code-based Post-Quantum Security
The foreseeable breakthrough of quantum computers represents a risk for communication which uses public-key cryptography. In order to prepare for such an event, embedded devices must integrate post-quantum cryptography, a set of algorithms based on mathematical problems that remains secure even in the presence of the quantum computers. Code-based is one of the most promising post-quantum cryptography. However, the implementation of code-based cryptography has two main challenges: i) satisfy performance and power constraints; and ii) resist side-channel attacks, which uses leakages derived from the implementation (timing, power or electromagnetic characteristics) to retrieve the secret information. The goal of this thesis is to implement a protected version (resistant to side-channel attack) of the newest version of the Gabidulin-Paramonov-Tretjakov code-based post-quantum cryptosystem. This Master thesis will be supervised by Dr. Johanna Sepúlveda (Chair of Security in Information Technology) and Prof. Dr.-Ing. Antonia Wachter-Zeh (Professorship for Coding for Communications and Data Storage).

Some of the following tasks might be covered:
- Getting familiar with Code-based Post-quantum security
- Getting familiar with Gabidulin codes
- Getting familiar with secure implementation
- Secure C/VHDL implementations
- Performance evaluation
- Security evaluation
The thesis can be done in German or English language.

- VHDL/Verilog or C/C++ programming skills
- Basic knowledge in security concepts
- Basic knowledge in channel coding or information theory

- Daniel J. Bernstein, Johannes Buchmann, and Erik Dahmen, editors. Post-quantum cryptography. Mathematics and Statistics Springer-11649; ZDB-2-SMA. Springer Berlin Heidelberg, 2009.
- M. Taha, T. Einsenbarth. Implementation Attacks on Post-Quantum Cryptographic Schemes. IACR, 2015.
- P. Loidreau. An evolution of GPT cryptosystem. In Proceedings of ACCT 2016, Fifteenth International Workshop on Algebraic and Combinatorial Coding Theory, Albena, 2016.

Dr. Johanna Sepúlveda (Doutora em Ciencias, Microeletrônica, University of São Paulo).
Mail:, tel.: +49 89 289 28256, room N1009.
Prof. Dr.-Ing. Antonia Wachter-Zeh
Mail:, tel.: +49 89 289 23495, room N4402.
Supervisor: Antonia Wachter-Zeh, Johanna Sepúlveda (Chair of Security in Information Technology, TUM)

Analyzing the Storage of Data in Synthetic DNA
Encoding digital data into synthetic DNA is a novel approach for data storage. Due to its natural robustness and size in molecular dimensions, it can be used for long-term and very high-density archiving of data. Since the DNA molecules can be corrupted by thermal process and the writing/reading process of DNA molecules can be faulty, it is necessary to encode the data using error-correcting codes. In this thesis, the student analyzes the type of errors that occur during read and write cycles using measurement data from DNA synthesis and sequencing experiments. Using these results, the student will develop error correcting codes to guarantee reliable storage.
Supervisor: Andreas Lenz

Designing codes for secret key generation and extracting the secret bits in left over hash lemma
The source model of secret key generation deals with the idea of Alice and Bob generating a key in a distributed manner from correlated observations. This key must be kept secret from an evesdropper. In this internship/thesis the student will start by looking at a simpler model which corresponds to the left over hash lemma. The student will build on some preliminary work done by me to design codes for the extraction of left over hash in a simple setting. After this the student will extend the work to design codes for distributed secret key generation for the source model.
Supervisor: Rana Ali Amjad

MIMO Multiport Communications
The topic of the thesis is to develop a simulator for MIMO communications including the transmit and receive RF frontends of a single user link. The simulator should be able to support different types of antenna elements and array configurations as well as matching circuits and amplifier models. In addition it should be able to estimate rates of communication over deterministic and stochastic channels.
Supervisor: Andrei Nedelcu

Rate-Distortion Theory for Sparse Sources
Rate-Distortion Theory for Sparse Sources This project investigates information theory limits for the lossy compression of sparse sources. Motivated by the recent mathematical theory Compressed Sensing that deals with the efficient acquisition and reconstruction of sparse signals, we try to determine the fundamental limits of digitally storing data created by such sources. A sparse source emits a string of symbols of which - loosely speaking - only a few contain information. There are different ways to model these sources. An example is the Gaussian spike source which emits a Gaussian symbol with probability p and a zero with probability 1-p.

Possible directions of a project are:
- Investigating different source models
- (Numerically) determining the rate distortion function of a sparse source
- Computing finite length performance bounds for sparse sources

- Information Theory (must)
- Pleasure with mathematics (must)
- Multiuser information theory (beneficial)
Supervisor: Lars Palzer

Forschungspraxis or MSCE Internships

Code design for Physical Layer Security
Wiretap channel represents the basic setup for physical layer security. It has been extensively studied in the last four decades and the fundamental limits of communication for this channel are known in a wide variety of scenarios. Nevertheless the only explicit code construction that can achieve wiretap secrecy capacity uses Polar codes. Designing codes for secrecy involve the combined design of codes for reliability and channel resolvability. In 2015 a new coding scheme for channel resolvability was introduced by Amjad and Kramer. The aim of this internship is to combine this channel resolvability code with existing channel codes in order to design wiretap code.
Supervisor: Rana Ali Amjad

Vector Network Coding Based on Rank-Metric Codes
Supervisor: Antonia Wachter-Zeh

Characterization of the effect of filtering on Four Wave Mixing
The nonlinearity of the fiber optic channel produces several frequency mixing effects, namely Cross Phase Modulation (XPM) and Four Wave Mixing (FWM). The repeated use of filters along the fiber reduces these effects, and improves channel isolation. In this thesis, we aim to find a way to characterize the FWM interference, and to find out how much of it is removed by the filters.
Supervisor: Francisco Javier Garcia Gomez

Open Student Jobs

no news in this list.

Theses in Progress

Bachelor Theses

Michael Müller: Development and Implementation of an Algorithm for a Bandwidth-Optimized Transmission of
Supervisor: Fabian Steiner, Firma SES/MX1

Alberto Diago Gallardo : Atmospheric Influence on Free Space Optical Communications
The work is based on Free Space Optical (FSO) communications and will include the following parts: • Case Study: Ground-to-Ground laser Links: o Link budget calculations; (Done) o Tracking Power budget calculations; o Scintillation analysis (optional: atmospheric simulations and fade statistics); (Ongoing) o Atmospheric Attenuation: Link availability calculations. (Ongoing) • Support the design, integration of testing of the “Frame-Steering Concept” as a demonstrator terminal for static links. (Ongoing) • Outdoor link demonstration and measurement campaign. • Analysis and evaluation of the measurement data.
Supervisor: Norbert Hanik, Luis Martin Navajas

Nurettin Turan: Implementation of a General Purpose LDPC Encoder
In the beginning of the thesis, the student will perform a literature research on existing general purpose LDPC encoding strategies and find out which variants are used in practical implementations in standards (Wifi, CCSDS, etc.). Next, the student will focus on the implementation of a scheme as described by the authors of [1]. As a programming language, we will target both C and Matlab. [1] T. J. Richardson and R. L. Urbanke, “Efficient encoding of low-density parity-check codes,” IEEE Trans. Inf. Theory, vol. 47, no. 2, pp. 638–656, Feb. 2001.
Supervisor: Fabian Steiner

Alyssa Akremi: Reduced complex precoding for CoMP massive MIMO sparse Channels
In this thesis, we investigate the low complex algorithms applicable to Zero-Forcing process of Coordinated Multi Point (CoMP) sparse channel matrices
Supervisor: Amir Ahmadian

Khalil Messaoudi: State Evolution Analysis of Quantized Compressive Sensing
The subject of this Bachelor’s thesis is the asymptotic performance analysis of scalar quantized compressive sensing (CS) under approximate message passing reconstruction.
Supervisor: Lars Palzer

Safwen Dridi: HDL Implementation of a Convolutional Interleaver
The student's task is to do research about interleaver theory, explore some implementations in MATLAB and finally implement a convolutional interleaver in VHDL or verilog.
Supervisor: Karl-Tasnad Kernetzky

Timothée Felicio: Implementation of Lower Bounds for the Error Probability of Gaussian Channels for Finite Blocklengths

In 1959, Shannon derived a sphere-packing bound that offers a lower bound on the decoding error probability for a Gaussian channel. This bound does not take any modulation constraints into account. In 1967, Shannon, Gallager, and Berlekamp derived a sphere-packing-bound that also considers modulation constraints. Nevertheless, the 1967 bound is not very close for short and moderate blocklengths.

In [1], an improvement of the sphere-packing bounds is provided that is applicable to short lengths and considers modulation constraints. The goal of the thesis is to analyze and implement this bound.

[1] A. Valembois and M. P. C. Fossorier, "Sphere-packing bounds revisited for moderate block lengths," in IEEE Transactions on Information Theory, vol. 50, no. 12, pp. 2998-3014, Dec. 2004.

Supervisor: Tobias Prinz

Katharina Rieke: Near ML decoding with OSD for short blocklengths
In this thesis the student will implement ordered statistics decoding as a means to perform decoding with near maximum-likelihood performance in the short blocklength regime. Besides, we will also study a formulation in the dual domain which is particularly beneficial for high rate codes. [1] M. P. C. Fossorier and S. Lin, “Soft-decision decoding of linear block codes based on ordered statistics,” IEEE Transactions on Information Theory, vol. 41, no. 5, pp. 1379–1396, Sep. 1995. [2] M. P. C. Fossorier, S. Lin, and J. Snyders, “Reliability-based syndrome decoding of linear block codes,” IEEE Transactions on Information Theory, vol. 44, no. 1, pp. 388–398, Jan. 1998.
Supervisor: Fabian Steiner

Master Theses

Mustafa Cemil Coskun: Successive Cancellation Decoding of Product Codes
Product codes were introduced by Peter Elias in 1954. He showed that the bit error probability can be made arbitrarily small by constructing a multidimensional product code with a positive code rate although it was far below the capacity limit. After almost half a decade, Erdal Arıkan has come with a channel code, which is provably capacity-achieving under successive cancellation decoding as block length tends to infinity.
The construction of both codes shows many similarities, which can be exploited. The thesis will investigate these similarities between two classes of codes and, in particular, it will borrow some tools from polar code setting and apply to product codes, e.g. successive cancellation decoder. After finding some theoretical results, the work will be concluded by implementing a simulator for product codes to show whether the findings are accurate or not.
Supervisor: Dr. Gianluigi Liva (DLR)

Keykavoos Afghahi: Methods for Adaptive Channel Allocation in a Multi-cell System
Supervisor: Markus Staudacher, Neda Petreska (Frauenhofer ESK)

Daniel Sander: Development of a measurement device for characterization of the signal quality in optical satellite-to-ground communications
The Institute of Communications and Navigation develops new systems and algorithms for optical communications with satellites and aircraft. The atmosphere significantly degrades signal quality, which can be seen in phase and intensity distortions as well as signal blockage by clouds. The institute operates an optical ground station to characterize these distortions and conducts measurement campaigns with satellites and aircraft. The new measurement device shall be designed to be directly attached aside the main receiver reflector of a ground station. The measurement device shall be independent from the receiver reflector e.g. the optical telescope but shall use the same tracking mount. The prime application will be the characterization of channel impairments at existing ground station sites worldwide, either of optical or RF type. This drives the requirement that the measurement device must be weatherproof taking into account typical climate conditions at ground station sites and it shall be of a small form factor (2” system). To ensure simple and continuous operations it must be able to be operated autonomously. In this work, this measurement device for signal quality shall be designed, assembled and tested. The design shall consider boundary conditions given by possible installations on an optical or RF receive antenna system as well as availability of possible signals sources in space. This includes analysis of characteristics of different antenna types (optical/RF), recommendations given by standardization activities regarding the space-to-ground link and expected dynamics and signal levels from potential test sources.
Supervisor: Norbert Hanik, Dirk Giggenbach / Florian Moll / Hennes Henniger

Kairen Liu: Information Theoretic Analysis of Neural Networks
Various types of neural networks have gained a lot of attention in recent years and have found numerous practical applications with impressive results. Albeit their success, their behaviour is not very well understood mathematically. The aim of this thesis is to approach the topic from an information theoretic perspective and see if one can use insight from information and coding theory to analyze/design neural networks for specific applications.
Supervisor: Rana Ali Amjad, Bernhard Geiger

Zafzouf Ghassen: Investigation into signal wave-forms for 5G & information theoretic analysis of MIMO OFDM systems
5G communication systems aim to put a large range of devices onto a network, ranging from high bandwidth systems which can transfer video and large files to small devices which only sporadically send data. Similarly the devices may be battery powered or not. The problem that can exist is that many modern communication systems are based on OFDM modulation which when used by multiple users simultaneously can have problems with synchronization, bit resolution, and the need to achieve good channel estimation. Our goal will be to characterize the fundamental information theoretic limits of such communication systems,as well as to design practical communication schemes that can approach these limits. This project will look into MIMO OFDM systems with a view to improve them towards being suitable for 5G communication systems.
Supervisor: Markus Staudacher, Dr. Konstanty Bialkowski

Qionghui Cao: Partial Parallel LDPC Decoder implementation on FPGA
Supervisor: Peihong Yuan

Jianwei Zhang: Probabilistic Signal Shaping for Short-Reach Optical Fiber Systems
Optical fiber systems form the backbone of the internet. Despite their large usable bandwidth, they are going to running out of capacity due to an increasing demand for services such as high-definition video streaming. In order to obtain the largest possible transmission rates for a fixed link, a shaped input should replace the common uniform input. In particular, non-iid inputs lead to less fiber nonlinearities, which improves the system performance. This Master thesis investigates such temporally correlated fiber inputs.
Supervisor: Tobias Fehenberger

Longxi Xu: FPGA implementation of Polar Encoder and Simplified Successive Cancellation Decoder
Supervisor: Peihong Yuan

Wenfei Li: Bit-Interleaved Coded Modulation and Multilevel Coding for Polar Codes
Supervisor: Peihong Yuan

Niklas Jünger: Error Correction for Data Storage in DNA
Supervisor: Andreas Lenz

David Ginthör: Development of a packet level encoding scheme and network protocol for a Hybrid-FSO/RF-Link
The Institute of Communication and Navigation of DLR developed a high rate Free Space Optical (FSO) downlink from an airborne to a ground station. However, it suffers from limited availability, as weather and atmospheric conditions significantly influence the signal link. Furthermore, the optical link is unidirectional and thus does not allow any flow-control. For operational purposes, the system also includes a bidirectional RF link. The objective of the Master’s Thesis is to develop a hybrid system that utilizes both transmission technologies – FSO and RF – to exploit the advantages of each. We will study how to increase performance of the unidirectional optical link by utilizing the bidirectional RF link to establish flow-control. Additionally, a switching algorithm shall be developed, which ensures uninterrupted data transmission in cases where only individual links are usable in order to maximize link availability and thus throughput of the system. This involves designing a protocol, which allows transmission over both links depending on the state of the channel. Information of the optical channel is acquired by analyzing statistics of the connection derived from the received data at the optical terminal. The software development includes analyzing and finding suitable transport protocols and focuses on efficient low-level programming in order to achieve high data rates of up to 10Gbit/s. Further, we will investigate a data-encoding scheme on the application layer to find possible solutions to increase reliability of packet integrity and hence robustness to packet losses over the optical link. The main challenge will be handling high data rates without the possibility to employ any sort of acknowledgment due to the lack of an uplink in the FSO.
Supervisor: Norbert Hanik, Dr. Julio Ramirez, DLR

Michael Reinsch: Latency-Measurement and -Validation of Safety-Critical Functions on Vehicles and Test Benches
In dieser Masterarbeit werden Latenzzeitmessungen sicherheitsrelevanter Funktionen der Längsdynamik „Abstandsregeltempomat“ und „Notbremsassistent“, sowie der aktiven Sicherheit „Auffahrwarnung“, von Kraftfahrzeugen durchgeführt. Zu Beginn werden die für die Funktionen relevanten Anforderungen und Wirkketten analysiert. Eine Wirkkette ist aus Steuergeräten, Sensoren, Aktoren und Datenbussen zusammengesetzt. Das Architekturmodell wird um Latenzzeitanforderungen ergänzt, sodass ein Sollmodell der Funktionen hinsichtlich Latenzen entsteht. Anschließend wird ein Konzept eines Messaufbaus erstellt, in dem die in der Architektur relevanten Meßpunkte definiert werden. Die benötigte und zur Verfügung stehende Messtechnik wird analysiert. Daraufhin werden Messungen am Hardware-in-the-Loop-Prüfstand sowie am Realfahrzeug durchgeführt. Die Meßergebnisse werden mit dem Sollmodell evaluiert.
Supervisor: Norbert Hanik, Sebastian Vöst, M.Sc., BMW Group

Maximilian Schädler: Frequency- and Time-Domain Enhanced Gaussian Noise Models for Fiber-Optic Communication Systems
Modern optical communication sytems suffer from nonlinear fiber effects that are the main limiting factor to increased spectral efficiencies. The split-step Fourier method, which is used to simulate the propagation of an optical signal through fiber, is computationally highly complex, which makes a detailed analysis of the impact of various system parameters on the fiber nonlinearities practically impossible. In this Master Thesis project, enhanced Gaussian noise models in the frequency and time domain are used to evaluate to optical communication systems. The aim is to find approximate solutions that describe the impact of the fiber nonlinearities on the signal.
Supervisor: Tobias Fehenberger


Mahmoud Marcam Helmy: Erstellung einer App für Smartphones der BITS mobile ERP Linie auf Basis von IOS Plattformen
Supervisor: Gerhard Kramer, BITS better it solutions GmbH, Wallenmahd 47, A-6850 Dornbirn

Lukas Püttner: Evaluierung verschiedener Tools zur Extraktion und Auswertung von Metadaten aus IP-Verkehrsdaten
Supervisor: Norbert Hanik, ESG Elektroniksystem- und Logistik GmbH, 82256 Fürstenfeldbruck

Francesco Montanari: Dynamic Dead Pixel Correction
Supervisor: Norbert Hanik, Fa. ARRI, Arnold & Richter Cine Technik GmbH & Co KG, München, Fr. E. Kögel

Barbara Lenz: Durchführung/Auswertung von RCS-Messungen
Supervisor: Gerhard Kramer, MBDA Deutschland GmbH, Schrobenhausen

Abidi Helmi : Programmierung einer C-basierten Ansteuerung für ein 1HE-Rack kompatibles TFT Display samt Touchpad
Supervisor: Gerhard Kramer, Attocube Systems AG, 80539 München

Yiming Yan: Mutual information between filtered narrow-band channels in a fiber optic link
In this internship, we consider a fiber optic link with several narrow-band channels, and measure the interference between the channels using mutual information. The goal is to assess the effect of several channel parameters on the channel interference.
Supervisor: Francisco Javier Garcia Gomez

David Jobst: Porting Interactive Flash Programs to HTLM5
The old LNTwww contains several Adobe Flash based programs to illustrate complicated topics in communications engineering. As Flash is not supported on many platforms, e.g. iOS, and will likely not be supported in the future at all, we need to migrate those animations to a modern format - otherwise the lntwww will not be usable by many students in future. An HTML5 canvas seems to be the best solution, as it is supported by may browsers including those on mobile phones. The student's task is to set up a framework for porting the programs and port at least one such application.
Supervisor: Karl-Tasnad Kernetzky

Forschungspraxis (12 ECTS)

Afghahi Keikavoos: Development of adaptive radio systems for industrial applications
Wireless real-time communication plays an increasingly pivotal role in industrial automation. Next generation high performance wireless technologies have to meet highest demands regarding latency, efficiency and reliability. Further, they have to be smart and adapt to an ever changing radio environment. In this internship you will participate in the research and development of adaptive wireless communication systems for application in the novel field of Industry 4.0. Using a Software Defined Radio (SDR) system you will develop a spectrum sensing procedure, which enables higher efficiency and reliability of wireless communication technologies for industrial applications. This internship will consist of the following tasks: · Getting familiar with the SDR development using USRP (Universal Software Radio Peripheral) and GNU Radio · Development of a spectrum sensing algorithm using the USRP hardware platform · Software development for interferer detection and smart adaptive channel allocation · Creation of a wireless network prototype, which dynamically adapts to a changing radio environment in an industrial scenario
Supervisor: Ginni Khanna, Neda Petreska

Muhammad Firas Hammosh: Is Online PCA Information-Preserving?
In this research internship, and overview over existing online (i.e., iterative, recursive, etc.) algorithms for Prinicipal Components Analysis (PCA) should be given. We try to find our which (if any) of these algorithms is invertible in the sense that one can reconstruct the original data from only looking at the rotated data. For those algorithms for which this is not possible, the (relative) information loss should be computed.
This work thus builds the bridge between PCA given knowledge of the covariance matrix (given-statistics) and PCA given only the sample covariance matrix (given-data). While no information is lost in the former, the information loss in the latter was shown to be substantial. We believe that the information loss of online PCA lies somewhere in between.
Supervisor: Bernhard Geiger

Thomas Wiegart: Evaluation of Non-Binary LDPC codes for Coded Modulation
In this Forschungspraxis, the student reviews the principles of non-binary LDPC codes and will apply it to a coded modulation scenario. In particular, the internship will deal with the efficient implementation of a non-binary LDPC decoder and the evaluation of different codes presented in literature for higher-order modulation. As the Forschungspraxis progresses, it should also focus on the combination with probabilistic amplitude shaping.
Supervisor: Fabian Steiner

Maximilian Schädler: Monte Carlo Integration for Optical Communication Systems
Modern optical communication sytems suffer from nonlinear fiber effects that are the main limiting factor to increased spectral efficiencies. The split-step Fourier method, which is used to simulate the propagation of an optical signal through fiber, is computationally highly complex, which makes a detailed analysis of the impact of various system parameters on the fiber nonlinearities practically impossible. In this project, Monte Carlo methods are studied in general and applied to optical communication systems. The aim is to find approximate solutions for non-closed-form expressions that describe the impact of the fiber nonlinearities on the signal.
Supervisor: Tobias Fehenberger

Emna Ben Yacoub: M-Type Approximation of Hidden Markov Models
In this research project, we replace transition and observation probability matrices of hidden Markov models (HMMs) by matrices where each entry is an integer multiple of integer M (i.e., is "M-type"). The problem is an immediate extension of approximating finite-length probability vectors by M-type vectors.

The Viterbi algorithm can be used to infer the state sequence from the observation sequence, given that the algorithm has knowledge of the transition and observation matrices. If, instead of the true matrices, the algorithm has knowledge only of their M-type approximations, this will lead to an increase in error probability. We try to find a connection between a probabilistic divergence measure between the true and the M-type model (e.g., Kullback-Leibler divergence rate, matrix norms, etc.) and this increase in error probability.
Supervisor: Bernhard Geiger, Rana Ali Amjad

Venkatesh Satagopan: Error-Correction for Partially Stuck Memory Cells
Supervisor: Antonia Wachter-Zeh

Anubhab Banerjee: Analysis of Some Code-Based Cryptosystems
Supervisor: Antonia Wachter-Zeh

Sayantini Majumdar: Sequence Reconstruction for Insertion and Deletion Errors
Supervisor: Andreas Lenz

Forschungspraxis (6 ECTS)

Joachim Neu: Evaluation of Spatially Coupled LDPC Codes
The student will review the basics of LDPC convolutional codes and implement a window decoder. Using regular LDPC code ensembles, the student will investigate their performance on the biAWGN channel. If time permits, the work will also consider coded modulation setups involving higher order modulations with probabilistic shaping.
Supervisor: Fabian Steiner

MSCE Internships

Amir Hossein Razaei Tabar: Code Design for Secret Key Generation/ Left over Hash Lemma
The source model of secret key generation deals with the idea of Alice and Bob generating a key in a distributed manner from correlated observations. This key must be kept secret from an evesdropper. In this internship/thesis the student will start by looking at a simpler model which corresponds to the left over hash lemma. The student will build on some preliminary work done by me to design codes for the extraction of left over hash in a simple setting. After this the student will (if time permits) extend the work to design codes for simple cases of distributed secret key generation for the source model.
Supervisor: Rana Ali Amjad