Research

• Beamforming design for satellite systems

• Tensor-based wideband parameter estimation
  • joint communication-radar systems

• Near-field localization

• High-resolution parameter estimation
  • multidimensional parameter estimation techniques
    • with applications in radar, mobile communications, sonar, seismology, and biomedicine
    • array calibration algorithms
    • realistic channel modelling based on estimated channel parameters
    • algorithms for time and frequency synchronization
    • prediction of time-varying mobile radio channels

• Transceiver design for 5G systems and beyond
  • hybrid analog/digital (A/D) precoding in massive MIMO
  • robust precoder design
  • tensor-based filtering
  • new multi-carrier waveforms
  • efficient two-way relaying

• Efficient channel state information acquisition
  • parameter estimation
  • channel estimation, tracking, and prediction

• Multi-user MIMO-systems (and smart antennas) with antenna arrays at the base station and (optionally) also at the terminals     
  • efficient transmit processing (depending on the available CSI at the TX)        
  • efficient receive processing, e.g., channel estimation and equalization        
  • efficient feedback signalling from the terminals to the base station

• Scheduling algorithms for SDMA (space division multiple access) 
• Realistic channel modeling for multi-user MIMO systems   
• Space-time-frequency coding   
• Cross layer designs
• Multi-hop systems
• Multiple access schemes               
  • multi carrier systems, CDMA, SDMA, UWB, infra red, etc.

• Fundamentals
  • Design of new algorithms for the efficient computation of tensor decompositions
    • , e.g., robust semi-algebraic CANDECOMP / PARAFAC, PARAFAC2, coupled tensor decompositions
  • Improved model order estimation schemes for multi-dimensional signals
  • Analytical performance evaluation of tensor-based techniques
  • Development of new tensor decompositions and new tensor tools, e.g., multi-linear Generalized SVD (ML-GSVD)
  • Maximum likelihood estimation of a low-rank probability mass tensor from partial observations
• Wireless communications
  • tensor-based channel estimation schemes in wireless communications (blind, semi-blind, or training-based)
  • channel prediction in MIMO systems
  • high-resolution parameter estimation techniques
  • channel estimation in the DFT beamspace domain for mmWave systems using a hybrid architecture
  • channel modeling in MIMO systems based on MIMO channel sounder measurements
• Multi-sensor systems in biomedical applications

• PRObability Mass Estimation in Tensors with Hidden Elements Using Structure (Methods, Theory, and Applications)
• jointly with Prof. A. Yeredor (Tel Aviv University, Israel)
• Duration (2022 – 2025)
• Project information

• “Advanced Hybrid Analog-Digital Massive MIMO Techniques for Millimeter Wave Wireless Systems (AdAMMM)”
• Duration: 2019 - 2022
• Project information on GEPRIS

• “Exploiting Structure in Compressed Sensing Using Side Constraints: From Analysis to System Design (EXPRESS II)”
• jointly with TU Darmstadt (Prof. M. Pesavento and Prof. M. Pfetsch)

• as a part of the DFG priority program CoSIP (SPP 1798) “Compressed Sensing in Information Processing“
• Project information
• Duration: 2018 – 2022

• “Exploiting Structure in Compressed Sensing Using Side Constraints – EXPRESS“
• jointly with TU Darmstadt (Prof. M. Pesavento and Prof. M. Pfetsch)
• as a part of the DFG priority program CoSIP (SPP 1798) “Compressed Sensing in Information Processing“
• Project information
• Duration: 2015 – 2018

• “Computational Advances in Multi-Sensor Signal Processing“ (CAMUS)
• jointly with TU Darmstadt (Prof. A. Gershman and Prof. A. Zoubir) as well as TU Berlin / TU Munich (Prof. H. Boche)

• project focus at TU Ilmenau: “Multi-dimensional Multi-Sensor Signal Processing Using Higher-Order Arrays“
• Duration: 2009 – 2014

• “Self-organized Mobile Communication Systems for Disaster Scenarios (MobiCom)”, DFG Graduate School
• Jointly with other research labs of the Institute of Information Technology and the Department of Computer Science and Automation
• Duration: 2009 – 2014
• GS Mobicom - International Graduate School on Mobile Communications

• “Development and evaluation of low complexity physical layer concepts for energy efficient UWB communications”
• as a part of the DFG priority program “Ultra-Wideband Radio Technologies for Communications, Localisation and Sensor Applications” UKoLoS (speaker: Prof. R. Thomä)
• Project Abstract
• Duration: (2007 – 2011)

• TakeOFDM ( Techniken, Algorithmen und Konzepte für zukünftige COFDM Systeme ), DFG Focus Program
• Project Abstract
• Duration: 2004 – 2010

• FP 7 STrategicREsearch Project, 2012 – 2015
• Project information on CORDIS 
• The goal of EMPhAtiC is to develop, evaluate and demonstrate the capability of enhanced multicarrier techniques to make better use of the existing radio frequency bands in providing broadband data services in coexistence with narrowband legacy services. The project will address the Professional Mobile Radio (PMR) application, and in particular the evolution of the Public Protection & Disaster Relief (PPDR) service currently using TETRA or other legacy systems for voice and low-speed data services. Both cell-based and ad-hoc networking solutions are needed for PPDR and will be developed.
  Our main emphasis is on filterbank based multicarrier (FB-MC) and single-carrier (FB-SC) waveforms for utilizing effectively the available fragmented spectrum in such heterogeneous environments. The core idea is to develop a multi-mode radio platform, based on variable filter-bank processing, which is able to perform modulation/detection functions simultaneously for different signal formats with adjustable centre frequencies, bandwidths and subchannel spacings. SC-FDMA waveforms are included in the study in order to relax the transmitter power amplifier requirements of mobile terminals. Enhanced OFDM solutions are also considered as alternatives aiming at minimal modifications to the 3GPP LTE standard, which serves as the reference system in the studies. In addition to physical layer functionalities, the project also develops MIMO and MAC-layer techniques, as well as relay networking solutions which are compatible and maximize the benefits of the waveform level solutions.
  The EMPhAtiC consortium has a strong expertise in the design of practical TETRA and ETSI BRAN systems and a very good track record in the development of FB-MC and FB-SC data transmission systems. We believe that the design of FB-MC schemes facilitating flexible and efficient multi-access spectrum usage, along with a proof of concept implementation, form the necessary basis for proposing better next generation broadband data solutions for the PMR evolution and other applications, including the 3GPP LTE evolution.

• "hOMEGigabit Access"
• FP 7 Integrated Project
• Duration: 2008 – 2011

• Project information on CELTIC-NEXT
• Celtic-Plus Innovation Award 2012

• Project information on CORDIS
• Project summary WINNER II

Integrated Project within the 6-th Framework Programme of the European Union. The key objective of the WINNER (Wireless World Initiative New Radio) project is to develop an innovative radio access concept in order to address high flexibility and scalability with respect to data rates and radio environments. Based on a detailed analysis of future user requirements the technology evaluation is being performed and a system concept definition is being developed.

• Project information on www.celticnext.eu

• Network of Excellence within the 6-th Framework Programme of the European Union
• FP 6 Network of Excellence, 2005 – 2007
• (jointly with EMT & HMT labs)

• Project information on CORDIS 
• The SAPHYRE (Sharing Physical Resources - Mechanisms and Implementations for Wireless Networks) project has stared in January 2010 and is a STREP funded by the European Union within framework program seven (FP7-ICT-248001).
  In current wireless communications, radio spectrum and infrastructure are typically used such that interference is avoided by exclusive allocation of frequency bands and employment of base stations. SAPHYRE will demonstrate how equal-priority resource sharing in wireless networks improves spectral efficiency, enhances coverage, increases user satisfaction, leads to increased revenue for operators, and decreases capital and operating expenditures.
  SAPHYRE represents a consortium that spans the entire chain from spectrum regulatory aspects, networking, physical layer to hardware implementation. The vision of SAPHYRE is to: SAPHYRE s main objectives are conceptually described as:
  • show how voluntary sharing of physical and infrastructure resources enables a fundamental, order-of-magnitude-gain in the efficiency of spectrum utilisation;
  • develop the enabling technology that facilitates such voluntary sharing;
  • determine the key features of a regulatory framework that underpins and promotes such voluntary sharing.
  • SAPHYRE analyses and develops new self-organising physical layer resource (spectrum, spatial coexistence) sharing models by a generalised cross-layer and cross-disciplinary approach.
  • SAPHYRE proposes and analyses efficient co-ordination mechanisms which require only small intervention (to counteract selfish, malicious users). In particular in sharing scenarios, incentive based design is applied in order to reduce regulatory complexity.
  • SAPHYRE develops a framework for infrastructure sharing to support quality of service with sufficiently wide carrier bandwidths and competition between different operators.

• ESA (European Space Agency) Project TOBOGGAN “sTudyofOn-groundBeamfOrminGtechnoloGiesAnd techNiques“,
  • jointly with EADS Astrium, Toulouse, France,and Fraunhofer IIS, Erlangen, Germany
• Duration: 2010 – 2012

• DLR Project, “Satellite Ground Stations with Electronic Beam Steering”
• Dec. 2011 – Aug. 2012

• ESA (European Space Agency) Network SatNEx IV (SATelliteNetwork of EXperts)
  • “Beamforming Optimization with Per-Element Power Constraints,” 2020

• Satellite Network of Experts V (SatNEx V)
• Project information

• worked on physical layer of visible light communication
  • Waveform design
  • Synchronization, channel estimation and detection
  • Miscellaneous aspects such as line coding, bit-loading, and precoding

• presently working on indoor VLC systems and V2X VLC systems
  • spatial multiplexing techniques
  • multi-user interference mitigation techniques
  • impact of non-linearities and dimming
  • receiver techniques and positioning
• Duration: Sept. 2020–Sept. 2024

• Demo implementation for the SEmi-algebraic framework for the approximate CP decompositions via SImultaneous Matrix Diagonalization (SECSI)
• Github project

The IlmProp is a flexible time variant frequency selective channel propagation modelling tool for multi-user MIMO systems. 

The main scope of the IlmProp is the generation of Channel Impulse Responses (CIR) as a sum of propagation rays. The channels are computed in delay time and frequency domain. The rays are defined by a three-dimensional geometry which can be either retrieved from measurements via high resolution parameter estimation techniques, or input manually. The code for the former will be published in future versions of the IlmProp. The latter permits the generation of frequency selective time variant MIMO channels which display realistic correlation in time, frequency, and space.

Further Information