Lab "Real-Time Signal Processing"

Basic Information

Lecturers:   Gerhard Schmidt and Thorben Kaak
Room:   -
Language:   English
Target group:   Students in electrical engineering and computer engineering
Prerequisites:   Skills in C programming language (for the DSS part), basic MATLAB knowledge (for the LNT part), diverse coding skills (for the ICT part)
Registration procedure:  

If you want to sign up for this laboratory, you need to register with the following information in the registration form

  • surname, first name,
  • e-mail address,
  • matriculation number,

Please note, that the registration period starts the 20.03.2017 at 8:00 am and ends the 27.03.2017 at 12:00 am. All applications before and after this registration period, will not be taken into account.

Registration will be possible within the before mentioned time under the following subsite - Lab Registration.

The registration is binding. A deregistration is possible by sending a mail with your name and matriculation number to This email address is being protected from spambots. You need JavaScript enabled to view it. until Wednesday, 29.03.2016 at 12:00. All later cancellations of registration will be considered as having failed the lab.

  • Preliminary meeting, Aquarium, 10.04.2017 at 14:00
  • Final presentations, Aquarium, 19.07.2017 at 12:00
Contents:   See the detailed introduction of the topics below.




ICT.1: LED-to-Camera Data Transmission (1 group of 3 students, Prof. Dr.-Ing. P.A. Hoeher)

In an optical Visible Light Communication (VLC) system the uplink channel is quite challenging. There are different approaches to establish an uplink channel like invisible infrared LEDs with photodetectors or hybrid wi-fi solutions.
In this project students are going to develop an optical transmission system with a RGB LED as sender and an USB webcam as receiver. A convolution code/Trellis code should be applied to modulate the three different colours. Arduino will be used as hardware platform for the transmitter. The decoding will be perfomed on a PC.
It is recommended that the participating students are familiar and interested in programming. The applied programming languages will be Python and C (in Arduino context).

ICT.2: Molecular Communication Testbed (1 group of 3 students, Prof. Dr.-Ing. P.A. Hoeher)

Molecular communication is a new biologically inspired communication paradigm, which uses molecules as information carrier. Especially for nanomachines, it is claimed as one of the key technologies to enable complex tasks in medical applications as targeted drug delivery. While the microscopic implementation is challenging, the principle of molecular communication can be easily explored in a macroscopic testbed. In this project, students are going to use the macroscopic molecular communication testbed in order to realize and analyze a simple text transmission link based on pulse position modulation.
It is recommended that the participating students are familiar and interested in programming. The applied programming language will be Python.

NT.1: Optical Duobinary Transmission (1 group of 2 students, Prof. Dr.-Ing. S. Pachnicke)

By using duobinary transmission, the signal bandwidth, compared to conventional binary modulation, can be reduced by about one half. Additionally, the signal has a higher dispersion tolerance and still can be received with a simple direct detection receiver. In this lab, the existing digital signal processing should be extended for duobinary transmission (precoding, encoding) and a simulative comparison to on-off keying should be done, followed by an experimental implementation.

NT.2: Digital Equalization Schemes (1 group of 2 students, Prof. Dr.-Ing. S. Pachnicke)

It is known that the optimal linear receiver, under the assumption of an inter-symbol interference (ISI) free channel and additive white noise, consists of a receiver filter matched to the pulse-shaper on the transmitter side, followed by a memoryless data decision. In real communications systems, the non-ideal channel generally causes ISI and hence can lead to an unacceptable amount of distortions, which consequently cause a wrong decision taking. One method to overcome this impairment is to apply an equalizer at the receiver side, which in fact implements a linear network with an inverse transfer function of that specific to the communication channel. The main aim of this project is to investigate and evaluate two different equalization formats: feed-forward equalization (FFE) and decision-feedback equalization (DFE), and make a qualitative comparison of the two schemes.

NT.3: Optical Signal Generation (1 group of 2 students, Prof. Dr.-Ing. S. Pachnicke)

In this lab we will learn the basic concepts of signal generation in an optical transmitter. Learn the difference between direct and external modulation formats. The focus will be on modulation formats using the interference modulator (Mach-Zehnder-Modulator [MZM]). In particular, the generation of Non-Return-to-Zero (NRZ) and consequent development into Return-to-Zero (RZ) and Differential-Phase-Shift-Keying (DPSK) will be investigated.

Real-Time Audio Processing (3 groups of 3 students, Prof. Dr.-Ing. G. Schmidt)

In this project, students are going to implement a speech enhancement system in the Kiel Real-Time Audio Toolkit (KiRAT). Algorithms within this framework are to be programmed in C language, the graphical user interface is written in C++ using the QT framework. Thus, it is expected that the participants have programming skills in C/C++. There will be up to three groups of three students that will create their own speech enhancement systems. Each group will specialize on one of the following algorithmic components:

  • Analysis and synthesis filterbanks,
  • Noise estimation, and
  • Noise reduction.


Schedule of talks

Attendance during all presentations is mandatory to pass the lab.

The schedule can be found below:

19. July 2017  Group Topic  Lecturer(s) Talk duration
12:00   Opening Thorben Kaak -
12:10 ICT.1 LED-to-Camera Data Transmission Nils Johannsen, Rebekka Weixler, Sebastian Grabert 25 minutes
12:40 ICT.2 Molecular Communication Testbed Sunasheer Bhattacharjee 15 minutes
13:00 DSS.1 Real-time-audio signalprocessing - Analysis/ synthesis filterbank Patrick Wiegand, Tobias Klawonn, Bastian Biedermann 25 minutes
13:30 DSS.2 Real-time-audio signalprocessing - Noise estimation Hannes Flieger, Thies Kuchenbecker, Jonas Weiss 25 minutes
14:00 DSS.3 Real-time-audio signalprocessing - Noise suppression Bastian Kaulen, Nico Simoski, Christin Willrodt 25 minutes
14:30 NT.2 Digital Equalization Schemes Ken Chan, Morten Stabenau 15 minutes
14:50 NT.3 Optical Signal Generation Moritz Paul Weihs, Adrian Bose, Ayman Soukieh 25 minutes
15:20   End    


Website News

20.01.2017: Talk from Dr. Sander-Thömmes added.

12.01.2018: New RED section on Trend Removal added.

29.12.2017: Section Years in Review added.

28.12.2017: Update of our SONAR section.

03.12.2017: Added pictures from our Sylt meeting.

Recent Publications

T. O. Wisch, T. Kaak, A. Namenas, G. Schmidt: Spracherkennung in stark gestörten Unterwasserumgebungen, Proc. DAGA 2018

S. Graf, T. Herbig, M. Buck, G. Schmidt: Low-Complexity Pitch Estimation Based on Phase Differences Between Low-Resolution Spectra, Proc. Interspeech, pp. 2316 -2320, 2017


Prof. Dr.-Ing. Gerhard Schmidt


Christian-Albrechts-Universität zu Kiel
Faculty of Engineering
Institute for Electrical Engineering and Information Engineering
Digital Signal Processing and System Theory

Kaiserstr. 2
24143 Kiel, Germany

Recent News

New PhDs in the DSS Team

Since January this year we have two new PhD students in the team: Elke Warmerdam and Finn Spitz.

Elke is from Amsterdam and she works in the neurology department in the university hospital in the group of Prof. Maetzler. Her research topic is movement analysis of patients with neurologic disorders. Elke cooperates with us in signal processing related aspects of her research. Elke plays ...

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