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Lab "Real-Time Signal Processing"


Basic Information

Lab overview  
  Lecturers:   Gerhard Schmidt and Bastian Kaulen  
  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
  • desired topic

Please note, that the registration period starts the 15.03.2021 at 00:00 am and ends the 09.04.2021 at 11:59 pm. All applications before and after this registration period, will not be taken into account.

Registration will be possible within the before mentioned time 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..

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 Friday, 18.04.2021 at 11:59 pm. All later cancellations of registration will be considered as having failed the lab.

Requirements, rules and commitments depend on the chosen topic and will be announced at the preliminary meeting (attendance is mandatory).

Attendance at all of the final presentations is mandatory as well to pass the lab.

The lab Real-Time Signal Processing and the preliminary meeting will take place with an online support.

  • Preliminary meeting, online meeting, 21.04.2021 at 13:00
  • Final presentations, online meeting, 07.07.2021 at 13:00
  Contents:   See the detailed introduction of the topics below.  



ICT.1: Text Transmission Using Fluorescent Dyes (1 group of 3 students, Prof. Dr.-Ing. P.A. Hoeher)

Molecular communication is a biologically inspired communication paradigm, which uses molecules as information carrier. Apart from being used in microscopic applications such as targeted drug delivery, its research focuses on potential applications in industrial facilities. For this purpose, the realization and evaluation of macroscopic testbeds are essential.

In this project, a new type of transmitter is being incorporated in our macroscopic testbed based on fluorescent dyes and channel impulse response for the increasing distances is to be investigated.

Thereafter, a communication link needs to be implemented in order to transmit random bit sequences through a pipe in order to perform channel estimation techniques. Furthermore, simple text messages can also be transmitted in order to compare them to the text messages produced using the analytical channel impulse response.

The participating students should be familiar with hardware and require basic Octave (preferably also Python) programming knowledge.

Further contact: M.Sc. Sunasheer Bhattacharjee & Dr.-Ing. Martin Damrath, ICT, {sub,md}


ICT.2: Optical CDMA in a VLC Transmission System (1 group of 3 students, Prof. Dr.-Ing. P.A. Hoeher)

CDMA is a well-known orthogonal transmission scheme in time domain for multi-user scenarios in RF systems. In this lab, the optical variant of CDMA (OCDMA) is to be evaluated in terms of applicability and performance in optical free-space transmissions. With respect to RF systems, the main difference in incoherent optical system is the lack of constructive and destructive signal interference. Signals cannot be canceled out, as only the intensities are added up.

Two different variants should be taken into account: i) two transmitter LED are used independently with two different CDMA sequences and ii) one single LED is used with electrically combined CDMA sequences as single transmitter.

This lab utilizes software simulation for the main system analysis. Afterwards, a hardware setup will be provided for taking home or working in the TF lab (depending on the current situation) for a validation of the achieved simulation results.

Basic Python programming skills are required as well as basic digital signal processing knowledge.

Further contact: M.Sc. Adrian Krohn, ICT/NT, This email address is being protected from spambots. You need JavaScript enabled to view it.


ICT.3: Direction of Arrival Estimation (1 group of 3 students, Prof. Dr.-Ing. P.A. Hoeher)

In civil aviation, transponders are used to provide flight information of aerial vehicles. Commonly, these are used by cooperative collision avoidance systems (ACAS) to prevent from dangerous situations. Towards autonomous flights in common airspaces, unmanned aerial vehicles shall use transponder signals to perform an additional direction-of-arrival (DoA) estimation. Since the freedom in antenna design and positioning is limited in these applications, light-weight solutions are of interest.

In this project, a distributed antenna array shall be modeled and the performance of the DoA estimation shall be simulated. To get a performance measure for further comparisons, an array of dipole antennas shall be assumed. The potential of certain dipole array geometries and arrangements shall be examined.

Simulations shall be performed using Matlab. Hence, Matlab programming skills as well as signal processing knowledge are required.

Further contact: M.Sc. Sami A. Almasri & M.Sc. Nils L. Johannsen, ICT, {saaa,nj}

NT.1: Erbium-doped Fiber Amplifier Modelling and Neural Networks (1 group of 2 students, Prof. Dr.-Ing. S. Pachnicke)

Erbium-doped Fiber Amplifiers (EDFAs) are the most common type of amplifiers in optical communication networks. Their purpose is to compensate the attenuation after a span of fiber. However, the implementation of an EDFA as a simulation model is not trivial since the gain characteristic is wavelength dependent. Most EDFA models today rely on numerical solutions of the rate equations which come with a high computational complexity. Machine learning algorithms are a promising way to simulate an EDFA.

An EDFA model based on analytical and/or numerical methods should be implemented and evaluated in MATLAB. After successful implementation, an artificial neural network (ANN) should be developed to mirror the performance of the prior implemented EDFA model.

The ANN should be able to react to the wavelengths of the input signal and output the gain non-linear gain characteristic of the modelled EDFA.

Both models have to be evaluated and compared which is more valuable for simulation purposes.

Further contact: M.Sc. Lars Kruse, NT

NT.2: Let’s Transmit Something Real for a Change… (1 group of 2 students, Prof. Dr.-Ing. S. Pachnicke)

As part of an investigation of a communication system, we usually use a pseudo-random sequence to simulate/emulate an information signal. The signal is assumed to have some specific properties, such as equally-probable information symbols. This could be true for information signals at large. However, when observing a real data, e.g. a digital image, these properties may not be valid.

In addition, we are usually considering waterfall curves as a way to assess the performance of a communication system. It is interesting, however, to see how exactly noise and distortion affect our real transmitted data, for example by means of a subjective observation of the received image.

As part of this topic, the students should program an image-to-bits and bits-to-image convertors in the chair’s simulation tool MOVE-IT. Using these modules, they should investigate, in simulation, the transmission of a digital image through an optical channel. All-optical equalization and noise-reduction techniques shall be used to improve the received images quality. The subjective observation of the received image, should be considered as part of the results to be presented in the final paper and presentation.

Further contact: M.Sc. Jonas Koch, NT

NT.3: SSBI Cancellation in Self-Coherent Transmission Systems (1 group of 2 students, Prof. Dr.-Ing. S. Pachnicke)

Self-coherent detection is a promising way to increase the data rate and impairment tolerance in optical direct-detection systems. However, signal-signal beat interference (SSBI) superimposes the useful signal and limits the performance.

In this project, different approaches for SSBI cancellation will be implemented and compared with respect to complexity and performance.

Basic Matlab skills are required.

Further contact: M.Sc. Tom Wettlin, NT

DSS.1-3: Real-Time Audio Processing (3 groups of 2 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 as well as active paticipation in the discussions is mandatory to pass the lab.

The schedule can be found below:

07.07.2021   Group   Topic   Lecturer(s)   Talk duration  
  13:00       Opening   Bastian Kaulen   5 minutes  
  13:05   ICT.2   Optical CDMA in a VLC Transmission System   Dennis Zdetski, Simon Hesselbrock, Michel Boldt   35 minutes  
  13:40   ICT.3   Direction of Arrival Estimation   Jonas Olschewski, Tobias Philipp, Leon Neidhardt   35 minutes  
  14:15   NT.2   Let’s Transmit Something Real for a Change…   Klara Görnig   15 minutes  
  14:30   DSS.3   Analysis and synthesis filterbank   Karoline Seidel, Patricia Fuchs   25 minutes  
  14:55   DSS.1   Noise estimation   Karolin Krüger, Christian Kanarski   25 minutes  
  15:20   DSS.2   Noise suppression   Moritz Boueke, Jan-Niklas Busse   25 minutes  



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