Lab "Real-Time Signal Processing"

Topics

ICT: Simulation of Flight Transponder Communication and MIMO Systems (1 group of 3 students, Prof. Dr.-Ing. P.A. Hoeher)

In today's aviation, aircraft transponders are a major part when it comes to collision avoidance (airborne collision avoidance system II, ACAS II) and traffic organization in civil airspaces. The increasing demand in traffic density already requires a reduction of radiation power used in the transmitters and interrogators, which directly affects the achievable range. The standards so far allow only single antenna processing or very limited usage of diversity.

Therefore, in this lab, a Mode S communication system shall be modeled using GNURadio and a software defined radio (SDR). A channel model shall be used and the channel shall be estimated. Based on the estimation, a beamforming vector shall be applied.

Further contact: M.Sc. Nils Johannsen, ICT, This email address is being protected from spambots. You need JavaScript enabled to view it.

NT.1: Handover prediction in 5G systems (1 group of 3 students, Prof. Dr.-Ing. S. Pachnicke)

One of the most critical points for autonomous vehicles is the handover process from one base station to another, since the vulnerability to additional latencies and even total connection loss is increased during this process. Hence, accurate handover prediction is an important step to ensuring a fast, stable connection and avoiding accidents.

In this project, multiple time-series forecasting models are to be implemented in Python and their capabilities predict handovers are to be evaluated and compared.

Further contact: M.Sc. Alexandr Langolf, NT

NT.2: Nonlinearity mitigation for optical signals with photonic Reservoir Computing (1 group of up to 3 students, Prof. Dr.-Ing. S. Pachnicke)

High launch powers required for optical signal transmissions with higher order modulation formats over long distances introduce signal impairments due to physical effects (e.g. Kerr-Effect) acting on the optical signal in the fiber. These can be partially compensated with photonic reservoir computing, reducing power consumption and latency compared conventional electronic signal processing. The ideal architecture of such reservoir depends on a multitude of different factors, such as the symbol rate, fiber type and application specific constraints (power budget, physical size, ...).

In this project an appropriate spatial reservoir architecture is to be selected and implemented using Python (PhotonTorch) to evaluate its signal equalization performance using different parameters.

Further contact: M.Sc. Sebastian Kühl, NT

NT.3: Let's break the nonlinear limit in an optical transmission system (1 group of 3 students, Prof. Dr.-Ing. S. Pachnicke)

Current optical fiber transmission systems are facing major challenges to handle the ever-growing global data traffic. The nonlinearity of the fiber is a limitation to further improve the spectral efficiency, since the systems are based on the assumption of a linear channel and are therefore not fully compatible. One possible solution to overcome this limitation is to use the nonlinear Fourier transform (NFT). The NFT is a solution of the idealized nonlinear Schrödinger equation that describes the propagation of light in an optical fiber, so that the nonlinearities are considered here.

In this project, a conventional linear system and a system using the NFT should be compared subjectively by transmitting a digital image. To do this, the students should program an image-to-bits and a bits-to-image converter in the chair's simulation tool MOVE-IT. An OFDM-like spectrum is then to be generated from the binary data, transformed once with an IFFT and once with an inverse NFT, and then transmitted through an optical channel. On the receiver side, an equalizer has to be implemented and the received images should be compared with each other and with the transmitted image in order to analyze the performance of the two systems used.

Further contact: M.Sc. Olaf Schulz, NT

DSS.1-3: Real-Time Audio Processing (2 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.

Further contact: M.Sc. Bastian Kaulen, DSS, This email address is being protected from spambots. You need JavaScript enabled to view it.

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:

Evaluation
	Current evaluation		Completed evaluations