Department Information Theory and Communication Systems
The Department lead by Prof. Eduard Jorswieck studies novel methods and tools from applied information theory, which are applied to analyse, optimize and design modern communications systems.
The research interests comprise essentially the following five areas: PhySec - physical layer security, CelCom - cellular communications, WiFi - modern wireless local area networks, WBAN - wireless body area networks and system theory and technology in the context of electronic media. The research concentrates on methodological and mathematical core topics (network information theory, multi criteria programming, game theory, information-theoretic security, multi-channel signal processing and machine learning) and their applications and implementations in timely and relevant communications techniques and systems (IoT, Industrie 4.0, Cyber Physical Systems, 5G and beyond).
CelCom: cellular communications
The research area comprises mobile communications systems of the fourth (LTE/A) and fifth (5G, NR) as well as future generations. The analysis and design of novel transmissions schemes (PHY+MAC) contains channel coding and decoding, signal processing at transmitters, receivers (or relays), as well as novel algorithms for resource allocation, scheduling and multiple access. In particular the flexibility of Software-Definied Networks enables an efficient resource allocation and robust and resilient communications. We develop novel algorithms for resource allocation and transmit strategy optimization in time varying dynamic complex interference networks.
Electronic Media: System Theory and Technology
During the past years, this research area is focused on the convergence of (wireless) broadcast and broadband networks. In this regard, a current development within 3GPP has taken place with Release 14 (March 2017). Further evolved Multimedia Broadcast Multicast Service (FeMBMS) is the successor to the first LTE broadcast concepts and allows the usage of an LTE carrier for dedicated broadcast. Our system “Tower Overlay over LTE-A+” (TOoL+) has contributed immensely to these enhancements. Its aim is to offload popular content from cellular broadband networks by integrating broadcast infrastructures, while also reducing energy consumption and network costs. Due to the adaption of the TOoL+ concepts, a transmitter and receiver prototype for FeMBMS could be implemented in a timely manner. At present, several field trials for FeMBMS using the IfN components are taking place in Europe, others are being planned. With the experience in TOoL+ and FeMBMS, current research is taking place in the area of 5G broadcast. New developments in 5G will be brought together in the topic “Tower Overlay over 5G NR” (TOo5G).
Furthermore, digital radio and communication via light are topics of this research area. For digital radio, the local interconnection in common-wave networks is being investigated in DAB+ and in Visible Light Communication (VLC) a research demonstrator has been developed which is constantly being further developed.
A flagship of our research is the Software Defined Radio Toolkit developed at IfN. Its extensive software library enables the flexible implementation of state-of-the-art transmission technologies.
PhySec: physical layer security
The realization of the vision of IoT and Industrie 4.0 (and following), in which multiple heterogeneous devices, actors, sensors, communicate reliably and securely, requires a novel security architecture, which scales with the number of devices and which does not require infrastructure. Physical hardware parameters and channel properties allow the development of novel information-theoretic secure primitives. The group studies the secure transmission over unreliable and unknown wireless channels, over optical multi-mode fiber links with wiretappers and over channels with states and active attackers.
WiFi: modern wireless local area networks
In the future, there will emerge dense private wireless local area networks, which operate interference limited and without coordination (on contrast to managed WiFi) and which congest the unlicensed spectrum. Additionally, data rates are increasing by the pure number of wireless devices and by data off-loading from macro cellular systems. Therefore, we need novel approaches and techniques for distributed interference management. We apply approaches from machine learning to optimize the wireless resources. Novel techniques for channel coding and decoding are found via atuo-encoding. WiFi networks (IEEE 802.11) are modelled, analyzed, optimized, efficiently designed and deployed, and their co-existence with other, e.g., cellular networks, studied.
WBAN: wireless body area networks
In medial applications, sensors and actors are placed on the human body in order to efficiently measure physical quantities and to report them to a wireless fusion center. Based on IEEE 802.15 standards, we develop novel techniques for distributed signal processing and coding, for handling the big data with low latencies and low energy consumption and sending them to central nodes. We consider signal processing and communications for wireless body area networks as well as applications of machine learning for reconstruction and removal or disturbing artefacts.