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/Diploma 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

Achievable Rate Regions for Multiple Access Relay Channels with Relay-source Feedback using Quantize-forward
Description

The multiple access relay channel (MARC) is an important model in cooperative communications since it captures both broadcast and multi-access.
Traditionally only information flow in one direction was considered, namely from the sources to the destination. We would like to extend this model by incorporating information flow (feedback) from the relay to the sources.
In previous work, we studied MARC with feedback using decode-forward (DF) and showed that feedback did increase capacity region of the MARC without feedback. We would like now to study MARC with feedback using compress-forward (CF) or quantize-forward (QF) to see whether one can get larger rate gains. The tasks of the thesis are:

1. Understand random coding arguments for the MARC with/without feedback using DF and the analysis for achievable rates.
2. Design achievability schemes for MARC using QF or CF and find the achievable rates. Compare the rates with QF and CF. Are they the same? If not, justify the difference.
3. Do the rates vary with the geometry of the network ? For example, if the relay is closer to the sources and far from the destination, is DF or QF the better choice? For a fixed coding scheme, e.g., QF, where should we place to the relay so that the rates are maximized?
4. Our initial assumption is that the feedback link is noise free. How would the coding scheme change if the feedback is noisy?
5. Use numerical simulations to back up the theories derived above.

Requirements
Information Theory is a MUST.
Multi-User Information Theory is a PLUS.

Reference
[1] J. Hou, R. Koetter and G. Kramer. Rate regions for multiple access relay channels with relay-source feedback. IEEE Information Theory Workshop (ITW) 2009, Oct. 2009.
[2] T. Cover and A. E. Gamal. Capacity theorems for the relay channel. IEEE Trans. Inf. Theory, 25(5):572–584, Sept. 1979.
[3] G. Kramer and A. van Wijngaarden. On the white gaussian multiple- access relay channel. IEEE Int. Symp. Inf.Theory, page 40, Sorrento, Italy, June 2000.
Supervisor: Jie Hou

Network Coding for Multicasting Prioritized Message Sets
we study the problem of communicating messages over wireline networks. Wireline networks, or classical networks, are mostly motivated by their applications in computer networks, where information can be sent between nodes essentially free of noise using proper data link protocols. The pioneer work in the problem of multicasting over networks is [1] where Ahlswede et al. (2000) consider the setting in which a source sends a common message to several receivers. They show that network nodes may need to perform network coding in order to achieve the capacity. In this project, we would like to investigate the role of network coding in communicating multiple prioritized messages over heterogeneous networks. Communicating prioritized messages are motivated in practice due to their applications in video streaming over heterogeneous networks.
The problem setup is as follows. A source wants to communicate two prioritized messages (A high priority message and a low priority message) with three users. Communication takes place over a wireline network. All three receivers demand the high priority message (e.g., a low resolution of the video), but one of them also demand the low priority message (e.g., a higher resolution of the video). The goal is to design network codes which ensure all the decodability requirements and yet allow high-rate communication.
The goal of this project is:
(1) To study optimal or near-optimal schemes for multicasting two prioritized messages over simple special-case networks
(2) Study the role of network coding in enhancing rates of communication
(3) Proposing new communication schemes, characterizing their achievable rate-region, and comparing them with the best possible ones
Pre-requisite (at least one of the following):
Basic knowledge of Network Coding (see [2])
Basic knowledge of Algorithms
Basic knowledge of Information Theory
[1] http://pdos.csail.mit.edu/decouto/papers/ahlswede00.pdf
[2] http://ect.bell-labs.com/who/emina/papers/NCF.pdf
Supervisor: Shirin Saeedi

Multi-User Massive-MIMO and Distributed MIMO Local-Area Scenario

Multiple-input-multiple-output (MIMO) techniques have emerged into current wireless communications standards such as LTE to increase the spectral efficiency. Massive-MIMO is a technology which promises to overcome the capacity crunch of today’s cellular networks. This Master Thesis aims to investigate Massive-MIMO and distributed MIMO applications in an indoor multi-floor scenario. Where multi-user scheduling should include frequency, time and spatial domain and should provide different degrees of fairness.

One is possinle approach is to serve with a basestation multiple users simultaneously with a fixed grid of beams (generated by a fixed precoder or a Butler-Matrix). The user terminals then feedback the measured SINR to the basestation that selects an appropriate beam upon the reported SINR.

The objective of the Masters thesis is to demonstrate the potential performance gains using massive-MIMO or distributed MIMO. A similiar approach has been studied in Schellmann et al. - Spatial Transmission Mode Switching in Multiuser MIMO-OFDM Systems With User Fairness.

The Master Thesis is a joint cooperation between TU Munich and Nokia Solutions and Networks in Munich.
For further information contact: stefan.dierks@tum.de

Supervisor: Stefan Dierks, Berthold Panzner (Nokia Solutions and Networks)

Powerline Communication for industrial application
Powerline Communication (PLC) is a well established technology for in-building data transmission. The HomePlug standard provides an easy to use interface. PLC is charackterized by modulation and coding schemes which ensure robustness against impuslsive noise and disruptions by the power transmission and transformation. Hence, the PLc becomes an interesting approach for industrial applications such as power charging stations for electrical cars or in the field of smart grid. This Master thesis shoudl analyze the PLC technology on the basis of the HomePlug Greenphy standard and its realization in todays chipsets. In particular, the optimization of the given PLC realizations for industrial use will be the focus of this work. This MAster thesis will be done in cooperation with Siemens AG Corporate Technology.
Supervisor: Elisabeth Georg

Open Student Jobs

12.03.2014

Lab Assistent Position Open

For the Summer Semester 2014 (SS14) we are looking for a lab assistent to help with delivering the Wireless Communications Laboratory. The preferred candidate should have either taken this laboratory before (previous name was...[more]


Theses in Progress

Bachelor Theses


Alexis Gonzalez-Argüello: Development of a Computer Implementation of Computational Methods for Time-harmonic Electromagnetic Field Modeling
Supervisor: Gerhard Kramer, Stellenbosch-University, South Africa, Prof. M. Botha

Sebastian Senninger: Comparison of Equalization Schemes for Optical Communication Systems
Optical fiber channels are subject to linear and non-linear distortions. Additionally, polarization-mode dispersion introduces intersymbol interference across many symbols of one wavelength channel. In the thesis, blind and data-aided equalization schemes are to be implemented and compared with respect to performance and complexity.
Supervisor: Tobias Fehenberger

Niklas Jünger: CS/JP Scheduling
Supervisor: Stefan Dierks

Master/Diploma Theses


Christopher Husmann: Modulation Classification in Wireless OFDM Systems with MAP Estimator
Ziel der Arbeit ist es eine effiziente Modulationserkennung für OFDM Systeme zu entwickeln. Modulationserkennung bedeutet, dass die Bits pro Symbol aus dem Empfangssignal geschätzt werden und nicht wie bisher üblich signalisiert werden müssen. Durch die Schätzung kann der Signalisierungsaufwand komplett eingespart werden. Im ersten Teil werden die Modulationen ohnr Information über den Sender geschätzt. Hierzu wird ein Likelihood-Schätzer entwickelt. Im zweitem Teil der Arbeit werden Informationen über den Bitloadingalgorithmus mit in den Schätzer einbezogen um die Performance zu steigern.
  • 1)Einarbeitung in die Themen: Modulationsklassifikation,,Maximum Likelihood Dectition,Statische Signalverarbeitung
  • 2)Punkt Approximation der Maximum Likelihood-Funktion (Dissertation Yun Chen):Implementierung der 4 Punkt Approximation in Matlab, Simulation in einem AWGN-Kanal, Fehleranalyse, Erweiterungen
  • 3)Wireless OFDM Systeme: Implementierung von IEEE 802.11a Standard in Matlab, Implementierung eines Rayleigh-Fading-Channel in Matlab
  • 4)Adaptive Modulation: Implementierung der Bitloading Algorithmen von Chow , Coiffi, Bingham, Campello and Fischer, Huber; Simulation mit IEEE Standard und Rayleigh-Fading-Channel
  • 5)MAP Estimator: Geeigneten Bitloading Algorithmus auswählen, Apriori Informationen des Bitloading Algorithmus mit ML Esitmator kombinieren, Simulation mit IEEE Standard und Rayleigh-Fading-Channel
  • 6)Optional: Hardware Realisierung des Entworfenen Systems
Supervisor: Onurcan İşcan, Dr. Yun Chen

Jiajing Niu: Optimization of Dispersion Maps for Coherent Optical Communication Systems
The vast majority of internet traffic is transferred over optical fibers that are subject to various kinds of distortions. Dispersion, which is a linear effect describing how the propagation speed of light in matter depends on its wavelength, can be dealt with either using dispersion compensation fibers (DCFs) or electronically in the digital signal processor (DSP). Some medium-reach networks still have DCFs deployed instead of relying on DSP compensation. By suitably choosing how much dispersion is compensated optically at which stage of the link, the overall system performance can be increased. Also, the gap to electronic compensation can be reduced.
Supervisor: Tobias Fehenberger

Patrick Schulte: Density Bending
Development and analysis of a practical zero-error, block-to-block distribution matcher that can be used for probabilistic shaping in digital communication systems.
Supervisor: Georg Böcherer

Marcin Pikus: Communication over the Rayleigh block fading channel
The goal of the project is to design a low complexity communication scheme that operates close to the theoretic limits.
Supervisor: Georg Böcherer

Julian Schiele: Development of a Framework for Fourier-Motzkin Elimination regarding Applications in Network Information Theory and Index Coding
Index coding is a special case of network coding and is interesting because of increasing demand for efficient wireless communication, e.g., video-on-demand applications. The index coding problem deals with communication scenarios where one sender wants to transmit N messages to N receivers over a single common link with presense of priori side information at the receivers. The aim is to minimize the number of transmissions while satisfying the communication requirements. We consider this problem because any instance of a network coding problem can be reduced to a index coding problem. Although the capacity region of a general index coding problem is not known, some inner bounds are developed using composite coding. However there is a large number of rate bounds involved. Thus, we use Fourier-Motzkin elimina- tion on the composite indices, which eliminates variables from a system of inequalities, to simplify the rate bounds. In this thesis, Fourier-Motzkin elimination is analyzed as a method to simplify groups of inequalities and a systematic framework is developed to tackle significant network information theory problems. The results developed will be applied to index coding problems to reduce the number of bounds involved. For this purpose, theory on polytopes and information inequalities will be studied.
Supervisor: Jie Hou, Ali Amjad, Prof. Young-Han Kim

Tasnad Kernetzky: Powerline Communications for Industrial Applications
Insbesondere im Heimumfeld hat sich die Powerline Kommunikation, basierend auf dem Homeplug Standard, etabliert und wird zunehmend eingesetzt. Wichtig für die Powerline Kommunikation ist, dass die eingesetzten Modulations- und Kanalcodierungsverfahren robust gegenüber Störungen sind, die bei der Leistungsübertragung und Energiewandlung auftreten und auf das übertragene Signal überkoppeln. Dies macht diese Verfahren auch interessant für den industriellen Einsatz. So werden Powerline Kommunikationsverfahren beispielsweise bei der Ladekommunikation für Elektrofahrzeug oder im Bereich des Smart Grid eingesetzt. In der Masterarbeit soll zunächst die Powerline Kommunikation nach dem Standard HomePlug Greenphy und deren Umsetzung in heute verfügbaren Chipsätzen analysiert werden. Darauf aufbauend sollen Optimierungsmöglichkeiten der Powerline Kommunikation z. B. bezüglich des gewählten Modulationsverfahrens, der Signalentzerrung, einer eventuellen Leitungscodierung, der eingesetzten Forward-Error Correction, für die Anwendung im industriellen Einsatz unter Kenntnis der Umsetzungen in diesen Chipsätzen erarbeitet und bewertet werden. Die Masterarbeit wird in Zusammenarbeit mit der zentralen Forschung der Siemens AG Corporate Technology durchgeführt.
Supervisor: Norbert Hanik, Anton Schmitt, Siemens

Ingenieurspraxis


Tamara Fiedler: Integration einer Toolerweiterung zur Überprüfung von Designrichtlinien in die bestehende MATLAB/SimuLink-Umgebung
Supervisor: Gerhard Kramer, Webasto Thermo&Comfort SE Kraillinger Straße 5 82131 Stockdorf, Fr. Löschberger

Alexander Domanski: Prozessanalyse & Optimierung
Supervisor: Norbert Hanik, BMW AG München, Abt. EA-803

Robert Fellendorf: Untersuchung der HF-Parameter für die Eignung zum Einsatz in IM-Messgeräten
Supervisor: Gerhard Kramer, Fa. Rosenberger, Hochfrequenztechnik GmbH & Co. KG, 83413 Fridolfing

Eghbal Darius Ketabtchi: Techn. Support und Kundenservice im Bereich IPTV und Durchführung von Produkttests mit Dokumentation
Supervisor: Gerhard Kramer, Fa. TERACUE AG, Schlossstr. 18, Odelzhausen, M. Schönberger

Shu Liu: Aufbau eines Evaluationsboards mit Vermessung durch einen Multiport-Netzwerk-Analyser
Supervisor: Norbert Hanik, Infineon Technologies AG, IFAG HR BPS SD, 85579 Neubiberg, Hr. R. Kuhn

Edvarts Berzs: Programmier- und Dokumentationsarbeiten in Matlab und Typo3

Die Webpräsenz des Lehrstuhls für Nachrichtentechnik ist mit Typo3 realisiert. Dabei wurden eini-ge Anwendungen als Typo3 Extensions realisiert. Diese benötigen eine ausführliche Dokumentati-on auf Englisch und einige kleinere Verbesserungen.
Für die Simulation eines Local Area Szenarios wurde eine umfangreiche Simulation in Matlab ers-tellt. Durch geänderte Anforderungen sind einige Umstrukturierungen und Änderungen nötig.
Herr Edvarts Berzs, soll dabei die Mitarbeiter des Lehrstuhls unterstützen und nach einer Einlern-phase selbstständig Programmier- und Dokumentationsaufgaben übernehmen.

Dabei unterteilt sich die Ingenieurspraxis in folgende Abschnitte:
• Einarbeitung in Typo3 und Kennenlernen der wichtigsten Elemente (Backend, Frontend) (1/2 Woche)
• Dokumentierung der Funktionalität einiger Typo3 Extensions (1/2 Woche)
• Vertiefen der Kenntnissen in Matlab (1 Woche)
• Erledigung von Programmieraufgaben in Matlab (3 Wochen)
o Restrukturierung und Modularisierung der Local Area Simulation
o Neuprogrammierung des Kanalgenerators
o Parametrisierung einiger Simulationsszenarios

Supervisor: Stefan Dierks

Dominik Fienko: Integration BS2000 SE Serie in Enterprise System Management
Supervisor: Gerhard Kramer, Fa. Fujitsu Technology Solutions, PDG ES S SWE 057, München