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).

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

Bayesian inference and tracking techniques for non-Lorentzian lineshape optical sources

Project description
Research on optical communication systems is nowadays focusing on methods and technologies which would allow higher capacity and increased transmission distance. The capacity of optical communication systems can be increased by a combination of spectrally efficient modulation formats and advanced receiver design. Currently, commercially available optical communication systems employ modulation formats that carry 2 bits/symbol/polarization, such as quadrature phase shift keying. In the near future, it is expected that in order to satisfy capacity demands, it will be required to increase the spectral efficiency to 4 or even 6 bits/symbol/polarization. This would require moving to 16 or 64 quadrature amplitude modulation (QAM).
Moreover, there is a strong focus on designing optical systems with reduced footprint and this requires large scale integration of optical components including semiconductors lasers. The semiconductor lasers exhibit a non-Lorentzian lineshape due to carrier induced frequency noise. This noise presents itself mainly as a resonance peak on the frequency noise power spectral density (PSD), which has been shown to play an important role on the system performance [4]. If phase noise tracking algorithms are not properly designed a large penalty in system performance may be obtained for higher order modulation formats (> 16 QAM) [4-5]. For non-Lorentizan lineshape more sophisticated tracking algorithms are therefore needed as the physics behind the laser phase noise process needs to be taken into account. As a proof-of-principle, it has been demonstrated theoretically and experimentally that Bayesian filtering methods are an effective tool in tracking phase noise that exhibits non-Lorentizan lineshape [5-6]. One of the challenges with Bayesian tracking methods is that they require knowledge of the parameters of the state-space describing the system. This is especially challenging to infer from the measured data due to the high dimensionality of the state-space as well as that the measured systems have typically a large number of unknown variables [7].

Objectives of the project
The main topic of this Master Project is implementation of Bayeisan inference techniques for parameter identification of state-space model for optical sources exhibiting non-Lorentzian lineshapes. The student will develop framework for parameter estimation based on expectation maximization which is an iterative approach for maximum likelihood parameter estimation. The inferred knowledge about the state-space will then be used to formulate digital signal processing algorithms for carrier phase noise compensation for coherent optical communication systems. If time allows, the student will test the framework on experimental data obtained for an optical transmission systems employing long haul transmission and higher order model formats.

Relevant literature
[1] Govind Agrawal, Fibre-optic communication systems, 2010
[2] Dirk van der Borne, PhD Thesis, 2008
[3] Essiambre et al., Journal of Lightwave Technology, vol. 28, 2010
[4] M. Piels, in Proceedings of OFC 2015
[5] L. Barletta, Journal of Lightwave Technology, vol. 30, no. 10, 2012
[6] D. Zibar, Journal of Lightwave Technology, vol. 33, no. 7, 2015
[7] C M. Bishop, Pattern recognition and machine learning, 2006

Supervisor: Luca Barletta, Darko Zibar (DTU)

Modulation and Channel Coding

Scope:I offer master thesis topics in the area of modulation, signaling and channel coding. The goal is to design transmission schemes for reliable communication close to the theoretical limits. We consider wireless, optical and wired communication channels and take power, bandwidth, and latency constraints into account.

Prerequisites: you should have attended one or more of the following courses: Information Theory, Channel Coding, Coded Modulation, Channel Codes for Iterative Decoding.

Start: Summer 2016.

Supervisor: Georg Böcherer

Channel Code Design for Security Primitives

We are looking for motivated students to work on (convolutional) code design for security applications. For realistic channel models, we want to test a set of codes to analyse their complexity, reliability, and secrecy performance. The thesis basically consists of code design for security primitives with given range of channel parameters, desired block lengths and BERs. Details will follow.

Interested students should directly send their CVs and transcripts.

Supervisor: Onur Günlü

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 non-uniformly spaced input can replace the common uniform input. Prerequisites for this thesis: digital communications (must!), basics in optical communication systems (important), information theory (equally important). If you are interested in this work, please contact me at tobias.fehenberger@tum.de to set up a personal meeting.
Supervisor: Tobias Fehenberger

Efficient Algebraic Decoding of Subspace Codes for Network Coding
Subspace codes were proposed by Kötter and Kschischang in 2008 for error control in random linear network coding (RLNC). The main idea is to encode information by the choice of a subspace rather than a choice of a vector. A basis for the selected subspace is then transmitted over a channel. The decoder returns the subspace that is closest to the received subspace according to some metric.
I offer topics on efficient (list and unique) decoding algorithms for subspace and rank-metric codes that allow to correct errors beyond the unique decoding radius.

Prerequisites:
You should be interested in Channel Coding and should have good knowledge in (linear) Algebra.
Supervisor: Hannes Bartz

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

Prerequisites:
- 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: Ali Amjad

Implementing a Constant Composition Distribution Matcher on a Zynq FPGA
Constant composition distribution matching[1] has recently received a lot of attention because it may be used to increase spectral efficiency using Probabilistic Amplitude Shaping proposed in [2]. The combination of both inventions was awarded the 3rd prize in renominated Ball Labs Prize [3]. In [1] an arithmetic coding scheme is proposed to index sequences of same weight or same composition, i.e., sequences of same length that consist of the same letters but permuted. The task of the Internship is to transform the encoder and decoder found at [4] from the programming language C into a hardware description language and evaluate its performance and complexity. A consecutive master's thesis could include improvement of the algorithm. We require the student to have some basic knowledge of VHDL and prior experience with the generic FPGA design flow and VHDL synthesis. Linux basics (using the command line, file system structure, ...) are also mandatory. [1] http://arxiv.org/abs/1503.05133 [2] http://arxiv.org/abs/1502.02733 [3] https://www.tum.de/en/about-tum/news/press-releases/short/article/32802/ [4] http://www.lnt.ei.tum.de/en/projects/constant-composition-distribution-matching/
Supervisor: Patrick Schulte, Karl-Tasnad Kernetzky

Development and Integration of a Demonstrations System for Advanced Communication Techniques
Development and integration of a demonstrations system for advanced communication techniques, which operate in an embedded Platform based on a combined ARM/FPGA System on Chip (SoC) architecture.

The activities to be carried out will start with the basic build of the system. This includes building and installing an appropriate Linux distribution on the ARM processor and making sure that all peripherals, particularly the FPGA, are accessible. After this initial stage the boards will need to be incrementally programmed to allow in the end full wireless communication between a transmitter and a receiver. Programming will be done in the first stage mostly in C / C++ and in the Linux shell, and in later stages also in VHDL/Verilog. Given the relatively high complexity of the task only students having good programming skills and a good understanding of the Linux operating system can be considered. An independent working style and the ability to solve relatively complex programming tasks is of advantage.

For more information, look here.
Supervisor: Tudor Ninacs, DLR

External Master Theses


Fundamental limits of cooperation with imperfectly shared state information

POSITION: EXTERNAL MASTER THESIS[PDF]

OPEN POSITIONS (FUNDED FROM ERC ADVANCED PROJECT "PERFUME")

Technical Context: The “PERFUME” project benefits from an “ERC Advanced” (European flagship) funding to investigate the so-called Smart Device Communications within the future Mobile Internet. Despite successes with past and current (5G) research, new paradigms leading to greater spectral efficiencies and intelligent network organizations will be in great demand to absorb the continuous growth in mobile data. Classical wireless design places the radio device under the tight control of the network. Pure network-centric designs, such as optical cloud- supported ones raise cost and security concerns and do not fit all deployment scenarios. More importantly these conventional approaches under-utilize growing local memory and computing capabilities at the device side (tablets, sensors, robotic objects such as wirelessly connected aerial drones etc.).

Our project envisions a radically new approach to designing the mobile Internet, which taps into radio devices’ new capabilities. Our approach recasts devices as distributed computational nodes solving together multi-agent problems, allowing to maximize the network performance by exploiting local measurement and information exchange capabilities. The projects sets novel objectives such as understanding new information theory limits for systems with decentralized information, the development of novel device communication methods, jointly with so-called team decisional statistical signal processing algorithms. The project will demonstrate the gains associated with exploiting the devices’ collective, network friendly, intelligence in pushing the frontiers of mobile Internet performance. Please visit http://www.eurecom.fr/cm/gesbert/erc for more details on the project.

Expertise and skills: Several master thesis are proposed for talented students with an excellent academic track . The project is at the frontiers of signal processing, communication theory, network information theory, game and optimization theory, artificial intelligence, as well as real-time implementation and experimentation, such that the subjects can be adapted to the desire and the skills of the students.

Practical Conditions: This position is located at EURECOM, in the French Riviera, near Antibes and Nice. The position being offered as part of the ERC project, the student will have a team of phd students and researchers providing interactions and a motivating work atmosphere. The starting date is flexible and can be discussed.

The student would be paid around 900 euros after taxes. Conditioned on the quality of the work realized, travels to international conferences could be funded. Ideally, this thesis would be the starting point of a doctorate at EURECOM.

For more information on any of the previous points, please do not hesitate to write to paul.dekerret@eurecom.fr or david.gesbert@eurecom.fr

Supervisor: David Gesbert and Paul de Kerret

Supervisor: Georg Böcherer, Prof. David Gesbert (EURECOM), Paul de Kerret (EURECOM)

Open Student Jobs

no news in this list.


Theses in Progress

Bachelor Theses


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

Tim Heinlein: Development of a Powerline Communication PHY Layer and Channel Simulator
The task of the (OSI) PHY layer in a communications system is the physical transmission of data. At the transmitter side, the PHY accepts packets from the MAC layer and transmits them to the receiver. At the destination, the PHY receives the data and passes the packet to the MAC layer of that device.
The student's task is to build a MATLAB simulator which takes packets from transmitters and delivers them to receivers. It has to drop and delay some packets with respect to different criteria. The connection to transmitters and receivers (clients) has to be done through Ethernet.
Prerequisites: Good programming skills, digital communications and basic knowledge about Linux.
Supervisor: Karl-Tasnad Kernetzky

Robert Markl: Development of an OFDM Physical Layer on a Zynq FPGA
The student's task is to develop an OFDM PHY layer on a Zynq FPGA located on a ZC706 evaluation board. The work will include include an FPGA design flow in System Generator for DSP (MATLAB/SIMULINK) and programming in VHDL.
Supervisor: Karl-Tasnad Kernetzky

Wafa Labidi: Error Propagation of Source coding schemes
lossless source codes are usually variable length codes. Variable length codes, however, suffer from error propagation and synchronization Problems. Consider for example the code:
a -> 0
b -> 1 0
c -> 1 1 0
d -> 1 1 1
and the sequence
a a b d c a b -> 0, 0,10,111,110,0,10
consider there was a transmission error of bit 4:
0, 0,111,111,10,0,10 -> a,a,d,d,b,a,b
There is error propagation that is however limited. In that thesis we want to investigate this effect
Supervisor: Georg Böcherer, Patrick Schulte

Emna Ben Yacoub: Community Detection Methods for Play Analysis
We create a metric to categorize sequences. Categories may be authors and sequences to analyze books they wrote. Furthermore we want to take a look at state space reductions of trained Markov chains.
Supervisor: Bernhard Geiger, Patrick Schulte

Aya Ben Salha: n-Markov Language Generator
The aim of the thesis is to build a program that learns a language based on plain text and generates a markov chain that can be used for imitating language. Language can be german, english or symphonies.
Supervisor: Patrick Schulte, Bernhard Geiger

Mohamed Chennoufi: Raptor Codes for IP Video and Audio Transmission
Supervisor: Patrick Schulte, Harald Weigold, Rohde und Schwarz

Simon Heihe: Markov Aggregation via Clique Partitions
Take a non-invertible function of a Markov chain - what you get is a stochastic process on a smaller state space that, in general, has less information than the Markov chain: Since the function is not invertible, it aggregates states, and the original state cannot be inferred from its aggregate alone.

In [1], we found sufficient conditions for such a non-injective function to preserve information: The output process contains the same information as the Markov chain, and the latter can be reconstructed from the former. In a later work, we found a connection between this sufficient condition and zero-error information theory. Specifically, one can construct a graph from the Markov chain and find an information-preserving non-injective function via partitioning this graph into cliques [2].

This bachelor thesis should apply this theory to a few practical examples: A clique partition algorithm should be implemented, and the algorithm should be tested at large, sparse Markov chains as they are common in chemical reaction networks or natural language processing. The prospective student should have good programming skills (Octave, Matlab, etc.) and should be interested in stochastic processes.

[1]: Geiger, Temmel, "Lumpings of Markov chains, entropy rate preservation, and higher-order lumpability"
[2]: Geiger, Hofer-Temmel, "Graph-Based Lossless Markov Lumpings"
Supervisor: Bernhard Geiger

Rami Ezzine: Lossy Source Coding Performance of One-Bit Compressive Sensing
The subject of this Bachelor’s thesis is the performance analysis of recent one-bit com- pressive sensing (CS) algorithms in a lossy source coding framework. Based on the seminal works of Donoho as well as Candes and Tao that deal with the efficient linear encoding of a sparse real-valued vector into a real-valued vector of smaller dimension, Boufounos and Baraniuk [1] proposed a one-bit CS algorithm where each linear measurement is quantized to +1 or -1. From these binary measurements, the original signal can then be approximated using various optimization techniques.
Since the one-bit CS procedure discards the amplitude information of the source signal, a popular source model is the uniform distribution on a sphere. However, applying a simple scalar quantizer to the amplitude of a signal, one might extend those algorithm to, for instance, Gaussian distributions. Another important source model is the binary source.
In lossy compression, the performance of a quantization code is usually measured with respect to its average distortion (the average quantization error) or excess distor- tion, that is, the probability of exceeding a given quantization error. Recently, there has been significant progress in finding the fundamental limits for the excess-distortion performance of fixed length vector quantizers, see [4] and the references therein as well as [5, 6]. These results can be seen as benchmarks for the performance of practical algorithms.
The aim of this thesis is thus to implement state of the art one-bit CS algorithms and investigate their lossy source coding performance for these source models.

Tasks
The following tasks will serve as a guideline.
• Familiarize yourself with the concept of one-bit CS and perform a literature review of state of the art one-bit CS algorithms. Good starting points are [1, 2, 3]
• Implement selected algorithms in MATLAB
• Perform Monte-Carlo simulations to numerically evaluate the average quantization errors and excess-distortion behavior of the algorithms for suitable source models
• Compare the results to existing bounds for fixed-length lossy source coding

References
[1] P. T. Boufounos and R. G. Baraniuk, “1-bit compressive sensing,” 42nd Annual Conference on Information Sciences and Systems (CISS), Mar 2008, pp. 16–21.
[2] J. N. Laska, “Regime change: Sampling rate vs. bit-depth in compressive sensing,” Ph.D. dissertation, Rice University, 2011.
[3] http://dsp.rice.edu/1bitCS/
[4] V. Kostina and S. Verdu ́, “Fixed-length lossy compression in the finite blocklength regime,” IEEE Trans. Inf. Theory, vol. 58, no. 6, pp. 3309 – 3338, Jun 2012.
[5] L. Palzer and R. Timo, “A converse for lossy compression in the finite blocklength regime,” 2016 International Zurich Seminar on Communications, Mar 2016
[6] L. Palzer and R. Timo, “Fixed-length compression for letter-based fidelity measures in the finite blocklength regime,” preprint, Jan 2016
Supervisor: Lars Palzer

Ilhem Brayek: 1 bit Massive MIMO Uplink
The target of this thesis is to implement and evaluate a massive MIMO uplink system with 1 bit ADCs at the receiver.
Supervisor: Markus Staudacher

Mohamed Amine Hadiji: Examination of Automated Tests
Supervisor: Markus Stinner, Carlos Martini

Anes Belkacem: Reliability Analysis for Secret-key Binding for Physical Identifiers
Secret-key binding for Physical Unclonable Functions (PUFs) is a promising technique to provide security to Internet of Things (IoT) rather than storing a key in Non-volatile Memory (NVM). Key-binding schemes using PUFs require an error-correction step due to the noisy nature of PUF outputs. The PUF post-processing scheme that uses the Discrete Cosine Transform (DCT) to decorrelate the source is a suboptimal but efficient approach. The DCT-based scheme uses an algorithm to satisfy the secrecy and reliability constraints simultaneously by optimizing a reliability metric for each DCT coefficient so that a certain block error probability can be achieved for the secret-key by using a linear block code. This thesis aims to find a better reliability metric to give performance guarantees to extract a fixed number of bits. Real PUF outputs will be used to determine the source and channel models for the DCT-based scheme and to check the security and reliability performance of the scheme with the new metric.
Supervisor: Onur Günlü, Bernhard Geiger

Master Theses


Houda Bannour: Design of a FEC Scheme for High Data Rate-Anti Jam speech waveform inteligibility optimization
The High Data Rate-Anti Jam waveform from Rohde&Schwarz allows audio signal transmission, supported by the MELPe vocoder with 2.4kbps. For multiple transmissions, the waveform uses the TDMA scheme. A TDMA slot contains MELPe frames and a header information with a total payload of 488bits. Under the Wideband mode, a TDMA slot is transmitted with a higher data rate, which means more bits per slot. These additional free bits shall be used in order to implement an FEC (Forward Error Correction) scheme to increase the robustness against channel noise and fading effects. Error Concealment (EC) techniques, such as bits interleaving, can be exploited on header and MELPe frames to reduce the effects of losses and burst channel errors. FEC combined with EC shall be designed in a way to find a balance between header and MELPe frames encoding schemes, in order to achieve an optimized bit error rate (BER), given by the case where all additional bits are used to protect the MELPe frames, without considering the slots’ losses due to the errors in header. The optimized BER ensures a minimum MOS (Mean Opinion Score) required for speech intelligibility.
Supervisor: Andrei Nedelcu, Dipl.-Ing. (FH) Stefan Kerger M.Sc

Clemens Bloechl: Aggregation of Hidden Markov Models - Theory and Applications
The topic of the thesis is to develop and analyze information-theoretic aggregation methods to reduce the state space and/or the observation space of hidden Markov models. Using the Kullback-Leibler divergence rate as cost function, we expect connections with the information bottleneck method, lumpability, and spectral aggregation techniques.

In the second part of the thesis, the developed methods shall be applied to practical examples, such as speech recognition systems. As a further example, the techniques shall be used to collapse output states of a discrete memoryless channel, without affecting the error probability of a Viterbi algorithm decoding a convolutional code.
Supervisor: Bernhard Geiger

Nicolas Blum: Blind symbol rate and timing synchronization estimators for a Non-Cooperative Multitone Receiver
Supervisor: Yingkan Chen, Joerg Biedermann (Rohde & Schwarz)

Tobias Prinz: Polar Codes for Higher-Order Modulation and Probabilistic Amplitude Shaping
Supervisor: Georg Böcherer, Peihong Yuan

Sara-Lee Steffan: Development and design of an optical transceiver module
Supervisor: Norbert Hanik, Philipp Putzer (OHB System AG)

Andreas Ditler: Numerical Evaluation of Capacity for Phase Noise Channels
Supervisor: Andrei Nedelcu

Marcel Grec: Fountain Codes under inactivation decoding
Fountain codes are a class of erasure correcting codes which can potentially generate an unbounded number of encoded symbols. Due to their flexibility they are a very efficient solution for the reliable multicasting setting, where a transmitter wants to deliver the same object (data file, video streaming etc.) to a number of receivers that have independent channels. In fact, fountain codes have been adopted in a number of standards, among others in:
  • UMTS Multimedia Broadcast Service (MBMS)
  • LTE evolved Multimedia Broadcast Service (eMBMS)
  • IETF RFC 6330, RaptorQ Forward Error Correction Scheme for Object Delivery
  • ITU-T H.701, IPTV multimedia services and applications for IPTV
The potential impact of fountain codes is especially high in the case of LTE, where an explosive growth of the number of services and users employing eMBMS is expected in the next years. The most preeminent services that will profit from eMBMS are:
  • Live event broadcasting to handhelds
  • Content delivery to automobiles
  • Software and firmware updates for connected devices
  • Emergency alerts
And at the core of all this services lie fountain codes. Despite the fact that fountain codes can be found in standards since a few years, the understanding of some of their aspects are not yet well understood. In particular, most of the works on fountain codes assume suboptimal iterative (belief propagation) decoding and asymptotically large information blocks. However, in practice, short information blocks are used and a different decoding algorithm employed, inactivation decoding. The goal of this Master Thesis is investigating several fountain codes under inactivation decoding. Concretely, the focus of this thesis is on analyzing the complexity of inactivation decoding. Inactivation decoding can be split into 4 different phases:
  • Triangulation
  • Zero-matrix procedure
  • Gaussian Elimination
  • Back substitution
The first phase of the algorithm, the “triangulation” phase can be carried using different techniques. Although inactivation decoding is widely used in practice, there is still no deep understanding of its many variants. The goal of the thesis is evaluating the algorithmic complexity of the different triangulation techniques. The tasks to be carried out are the following
  1. Perform a Literature survey on inactivation decoding for fountain codes
  2. Analyze the algorithmic complexity of different triangulation techniques.
    • Maximum component inactivation
    • Maximum weight inactivation
    • Permanent inactivation
    • Random Inactivation
  3. Develop a realistic simulator for the different inactivation strategies.
  4. Compare the different inactivation techniques in a realistic setting.
Supervisor: Patrick Schulte, Francisco Lazaro-Blasco

Janis Surof: Intradyne Reception in Optical Satellite Links
The master thesis is set out to perform analytical and experimental feasibility study of an optical BPSK and QPSK optical link in GEO satellite system scenario. The task is to analyse and simulate a coherent phase-modulation optical link with respect to optical signal and noise power limitations, linear and nonlinear system e ects and atmospheric distortions. Then, series of equalising and correcting algorithms will be developed in MATLAB and applied to the transmitted signal in order to compensate for the simulated distorting e ects. The analytical results will be later experimentally demonstrated in laboratory conditions.
Supervisor: Tobias Fehenberger, Dr. Juraj Poliak (DLR)

Xianhe Yangzhang: Capacity Estimation using Nonlinear Frequency-Division Multiplexing for Optical SMF Channel
The capacity of the single-mode fiber (SMF) at high-SNR region is a critical topic for researchers in optical and information theory society. Due to the application of linear methods such as Nyquist-pulse shaping, OFDM, WDM, SDM, etc. in optical SMF transmission, the fiber Kerr-effect induced nonlinearity causes significant intra-/inter-channel interference which might lead to an underestimation of the capacity limit for SMF channel. Nonlinear frequency-division multiplexing (NFDM) based on the nonlinear Fourier Transform (NFT) is a promising approach to overcome the bottleneck of the data rate at high-SNR region. It treats fiber nonlinearity and chromatic dispersion as essential parts of the transmission such that the channels don't interfere with each other in nonlinear frequency domain. In this master thesis, an NFDM system at the defocusing case using forward and backward NFT will be developed and evaluated , aiming at giving a better lower bound of the capacity for optical SMF channel.
Supervisor: Yingkan Chen, Prof. Mansoor I. Yousefi

Sirui Zhang: Non-Asymptotic Complexity of Polar List Decoding
Supervisor: Peihong Yuan

Zeng Fan: Soft-Output Decoding of Polar Codes
Supervisor: Peihong Yuan

Manuela Meier: Syndrome Decoding of Insertions and Deletions
Subspace codes are used for error control in random linear network coding (RLNC) and can be constructed from the Reed-Solomon like Gabidulin codes. A channel model for RLNC is the operator channel which incorporates insertions (of additional code symbols) as well as deletions (of code symbols). It has been shown, that interleaved or punctured subspace codes are very resilient against insertions if an interpolation-based decoder is used. The goal of this thesis is to analyze syndrome-based decoding schemes for interleaved evaluation codes that are more resilient against insertions than deletions. The results should be verified by simulations.
Supervisor: Hannes Bartz, Vladimir Sidorenko

Julian Renner: Multidimensional Probabilistic Shaping for the Nonlinear Fiber Channel
Probabilistic shaping has shown to give large sensitivity gains for the additive white Gaussian noise (AWGN) channel and also for the nonlinear fiber channel. For a fiber-optic communication system, the optimal input distribution is unknown, and typically, heuristics are used to realize shaping. In this thesis, an approximate model of the fiber channel is used to numerically find and evaluate optimized input distributions, while exploiting the multi-dimensional nature of the considered channel.
Supervisor: Tobias Fehenberger

Berkay Köprü: Coding Schemes for Multiple Access Communications
Multiple access channel (MAC) can be seen as the model where two or more transmitters send information to a common receiver. For instance, multiple mobile phones communicating to a base station can be modeled as a MAC. The main challenge in MAC is that the receivers may share the transmission channel in an uncoordinated way, such that their transmissions can interfere. This problem is solved in many modern communication systems by allocating orthogonal resources (like time slots or frequency bands) to the transmitters such that the interference is avoided. However, although it is a practical solution, orthogonalization is not the optimal solution if considered from an information theoretic point of view. According to the theory, non-orthogonal transmission in MAC can be beneficial in many scenarios, however for these scenarios the coding schemes should be designed carefully to benefit from the non-orthogonal communication. Next generation cellular systems will support a multitude of services where multiple nodes are involved in the communications simultaneously, including vehicle-to-vehicle communications and massive machine communications. For these highly challenging communication scenarios, the design of the multiple access schemes will be of practical importance. In this thesis, practical coding schemes for MAC should be investigated, implemented and compared to the theory and to the existing solutions. Task Description: The tasks of the student can be summarized as follows: Studying the multiple access related scenarios for the next generation communication systems. Determining the correct channel models for the related scenarios. Basic theoretical evaluation of the scenarios according to the given models and comparison to the performance of the orthogonal schemes. Studying the already proposed solutions like IDMA and SCMA. Understanding the basic tools for channel code design, like EXIT analysis. Development and implementation of practical coding schemes for the selected multiple access scenarios. Simulations and comparisons to the state-of-the-art solutions and to the theory The actual tasks will be defined jointly with the candidate according to his background and the achievements. The focus can be put either on the theoretical analysis of multiple access schemes for different scenarios, or the more practical design and evaluation of coding schemes and receiver algorithms.
Supervisor: Patrick Schulte, Dr. Onurcan Iscan (HUAWEI), Dr. Ronald Boehnke (HUAWEI)

Ingenieurspraxis


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

Ulrich Patrick Sandoval: Weiterentwicklung des Netzwerkanalysetools (NAT) mit Schwerpunkt auf Testfälle
Supervisor: Gerhard Kramer, Fa. Infineon Technologies, Neubiberg, Hr. Lippmann

Hasan Yagiz Özkan: Image Tracking Algorithm Development
Supervisor: Gerhard Kramer, Fa. Bases Teknoloji Arge Sanay, Hr. T. Cirak, Istanbul

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

Matthias Engelhard: Erstellen von Spezifikationen und Testplänen sowie Dokumentation für Skriptprogramme
Supervisor: Gerhard Kramer, Continental Automotive GmbH, 93055 Regensburg, Dr. Kelbeck

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

Jonathan Roth: Referenz-PLL mit umschaltbarer Zeitkonstante
Supervisor: Norbert Hanik, Fa. Rohde & Schwarz GmbH & Co. KG, 81671 München

Forschungspraxis (12 ECTS)


Liu Xiaotong: Simulator in Matlab for MIMO Multiport Communications
The purpose is to build a Matlab simulator that can incorporate both circuit and channel models for MIMO communications in order to evaluate the achievable rates with different RF front-end designs in various propagation scenarios.
Supervisor: Andrei Nedelcu

Julian Renner: High-dimensional Probabilistic Shaping for Optical Communication Systems
Project description

Coded modulation is a technique to match the communication system to the communication channel. In this Forschungspraxis, the focus is on shaping the symbol probabilities of QAM input for an optical communication system to achieve high spectral efficiency.

Supervisor: Georg Böcherer, Tobias Fehenberger

Edward Wall: Finite-Precision Gaussian Mixture Models
In practical systems, Gaussian mixture models can only be presented with finite-precision. The first goal of this research internship is to survey the literature about how this problem is usually dealt with: Can we trade parameter precision for the number of mixture components? Can we restrict the covariance matrix to be diagonal? To be an identity matrix? What kind of cost functions are used to characterize these trade-offs? As a second goal, relative entropy shall be used as a cost function. For a simple multivariate Gaussian distribution and a given finite precision, the Gaussian distribution with quantized parameters minimizing relative entropy shall be computed.
Supervisor: Bernhard Geiger

Lukas Holzbaur: Error-trapping for the Operator Channel
Subspace codes by Koetter and Kschischang (KK) can be used for error control in random linear network coding (RLNC). A common channel model for RLNC is the operator channel, which inserts and deletes dimensions from the transmitted subspace. Each basis vector of a KK subspace code consists of a header, which is common for all codeword (subspaces). The size of this header should be small compared to the dimension of the vector space. This is the case for punctured or interleaved KK subspace codes. The student's task is to implement a decoder for punctured subspace codes and investigate the impact of the header structure on the decoding performance.
Supervisor: Hannes Bartz, Vladimir Sidorenko

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

MSCE Internships


Hussein Hammoud: Lossy Compression of the Bernoulli-Gaussian Spike Source in the Finite Blocklength Regime
The subject of this research internship is lossy compression for the Bernoulli-Gaussian (BG) spike source. This source emits independent and identically distributed random variables each of which is the product of a Bernoulli random variable with and an independent Gaussian random variable. We are interested in the optimum coding rate for a given finite block length subject to the constraints that source symbols which are equal to zero are reconstructed as zeros and those that are not equal to zero satisfy an average squared error distortion constraint.
Supervisor: Lars Palzer

Muhammad Umer Anwaar: Coding Techniques for Natural Language Processing
In this internship the student will review current state-of-the-art techniques for Natural Language Processing (with a focus on Machine Translation). Specifically, the student will check which of these techniques employ Hidden Markov Models, and whether they have connections to decoding algorithms for channel codes. Finally, the student should present a recommendation if, and how, list decoding methods can be applied in machine translation. If you are interested to pursue this topic for your Master's thesis that is also possible.
Supervisor: Ali Amjad, Bernhard Geiger