Erich Leitgeb

• Graz University of Technology

The ever-increasing throughput demand is aimed to be met by the combined use of the radio frequency (RF) and free space optical (FSO) spectrum. However, making this combination into practice is still uncertain, especially for high-mobility scenarios with a limited coherence window for beam training and tracking. Accordingly, significant research ef...

We study the phenomenon of mirrorless lasing and backward emission from the viewpoint of macroscopic electromagnetism by assigning complex permittivity to a light-emitting or amplifying layer. The amplifying medium is described using complex permittivity without detailing the micro-processes in it. The analysis is performed using the well-known...

Guest Editorial written for a Special Issue on "Recent Trends and Advances in Telecommunications and Sensing"

Modulating characteristics of transmissive and reflective Fabry–Perot type multi-nanolayer conductor–dielectric electro-optical modulators (EOMs) for chip-to-chip free space optical interconnection are analyzed via wavelength-scale electromagnetic modelling. For electromagnetic analysis the frequency-domain method of single expression is used. The...

The performed numerical analysis demonstrates an application of a surface plasmon phenomenon for efficient modulation of light intensity in the reflection mode. A supply of modulating high frequency electrical signal to an electro-optical thin layer located upon a thin metallic layer supporting surface plasmons is assumed. The narrow plasmonic and...

Given the escalating need for greater bandwidth, there is a growing interest in implementing mechanisms that ensure reliable and optimal service levels for specific traffic classes, especially during periods of heavy network traffic. One such mechanism is the prioritization mechanism, where certain portions of resources are exclusively allocated to...

Free-space optical (FSO) communication is a line-of-sight (LOS) communication technology that uses light, typically lasers, to transmit data through the atmosphere. FSO can provide high data transfer rates, but factors like weather conditions can affect its performance. Like fog, smog also degrades the availability and reliability of FSO links, as...

Accurate indoor positioning is becoming increasingly important, especially in highly automated industrial environments with robots. In addition, LED-based lighting is also being used more and more frequently in such application fields. In the present work, the possibility to exploit the LED lighting infrastructure with a novel approach for implemen...

This study emphasizes the importance of conducting a comprehensive analysis considering the Cn2 atmospheric parameter for a reliable assessment of the seeing value. It highlights the use of the ECMWF ERA5 model to simulate pressure, temperature, and humidity profiles, enabling the evaluation of optical degradation. Accurate modeling and monitoring...

One of the challenging riddles that is set by light is: do photons have wavefunctions like other elementary particles do? Wave–particle duality has been a prevailing fact since the beginning of quantum theory thought; in electromagnetism, light is already a kind of undulation, so what about the waves of probability then? Well, Quantum Field Theory...

Electro-optical modulators (EOMs) play an essential role of modulating light for free space chip-to-chip optical interconnection. Optical properties of reflective type multi-nanolayer EOM are modelled numerically by the method of single expression. Reflective properties of Fabry-Perot type EOM consisting of electro-optical spacer of LiNbO3 covered...

This paper presents a novel approach to improving wireless communications in harsh propagation environments to achieve higher overall reliability and durability of wireless battery powered sensor systems in the context of in-vehicle communication. The goal is to investigate the physical layer and establish an antenna recommendation system for a spe...

Today’s air traffic management (ATM) system evolves around the air traffic controllers and pilots. This human-centered design made air traffic remarkably safe in the past. However, with the increase in flights and the variety of aircraft using European airspace, it is reaching its limits. It poses significant problems such as congestion, deteriorat...

This work proposes an indoor positioning solution to achieve positioning in a low complex way. Our solution approach is based on frequency-modulated light sources without the need for complex modulation and encoding schemes. By utilizing a least-square approximation, the composition of the frequency spectrum of the impinging light on a receiver uni...

Free Space Optics (FSO) technology enabling next-generation near-Earth communication is prone to severe propagation losses due to atmospheric-turbulence-induced fading and Mie scattering (clouds). As an alternative to the real-time evaluation of the weather effects over optical signal, a state-of-the-art laboratory testbed for verification of slant...

Over a number of years the ever-increasing growth of traffic transferred over the internet has become a common pattern. This particular trend was made even more discernible in 2020 when it was a common practice to use videoconferencing and other services that provide the possibility of distributed group work. This increasing use of the network is a...

In the near future, the demand of wireless communications will elevate tremendously. The rapid increasing number of mobile end devices will require a much higher data rate connection than nowadays e.g. to smart homes (Internet of Things, IoT) or to the Internet. The radiation power pattern of base stations and mobile end devices will completely cha...

With the rise of LED (light-emitting diode)-based luminaires, artificial lighting has become a technology platform, which, besides providing illumination, also provides communication and positioning functionalities. Apart from this, most recently Visible Light Sensing (VLS), in which lighting is used for sensing purposes, emerged as another embodim...

This article is a herald of our Book 3 devoted to good ICT (Information and Communication Technology) design implementation practices gained during design and development of the Polish pioneering Computer Control Systems destined for the Steel-Bar Mill of a Warsaw Metallurgical Plant in Warsaw and for the Michelson Interferometer of the Nicolas Cop...

A physical-layer secure data encryption algorithm is proposed and demonstrated using chaotic constellation mapping associated with probabilistic shaping (PS) for orthogonal frequency division multiplexing passive optical networks (OFDM-PONs). The constellation of the encrypted data is uniformly distributed after chaotic diffusion in quadratic-ampli...

Optical wireless networks realized by means of gigabit optical wireless communication (OWC) systems are becoming, in a variety of applications, an important alternative, or a complementary solution, to their fiber-based counterparts. However, performance of the OWC systems can be considerably degraded in periods of unfavorable weather conditions, s...

With the ever-increasing demand for bandwidth, appropriate mechanisms that would provide reliable and optimum service level to designated or specified traffic classes during heavy traffic loads in networks are becoming particularly sought after. One of these mechanisms is the resource reservation mechanism, in which parts of the resources are avail...

With the advancement in silicon interposer teehnol- ogy and Through Silicon Vias (TSVs) [1], [2], heterogeneous 2.5D integration at mm-wave frequencies is becoming more approachable than ever. In this work, we investigated co-planer Ground- Signal-Ground (GSG) wirebonds as cost-effective interconnect for RF 2.5D applications. On-silicon GSG wirebon...

DWDM networks make use of optical switching networks that allow light waves of multiple lengths to be serviced and provide the possibility of converting them appropriately. Research work on optical switching networks focuses on two main areas of interest: new non-blocking structures for optical switching networks and finding traffic characteristics...

Achieving reliable wireless communications using COTS devices in vehicles has been an unattainable target so far. One reason is that the high safety requirements of automotive applications cannot be met by the relative unreliability of wireless communication in such complex environments. This poster presents an approach for utilizing RSSI as a firs...

LD 6 is our “Generalized Colleague”, a Leading Designer specialized in computer and communication system hardware, and pioneering/emerging/novel ICT application projects, in particular those intended for computer control systems, especially for the electric power industry. He assumed that the pioneers of the computing industry, of the best results...

Using ultra-high repetition rate lasers ( $\ge {100}\;{\rm kHz}$ ) is one of the most promising strategies for the next generation of satellite laser ranging (SLR) systems. We present successful 1 MHz repetition rate SLR to targets up to inclined geosynchronous orbits at nighttime. Among those, a maximum return rate of up to 53% was achieved, equiv...

The performance of free‐space optics links strongly depends on scintillation effects caused by the atmospheric turbulence appearance. A widely adopted way to counterbalance the expected deterioration due to scintillation is to employ cooperative and multi‐hop arrangements. However, the use of multiple relays increases significantly the complexity o...

Satellite laser ranging (SLR) with higher repetition rate is the recent trend for its various advantages. Laser backscatter (coincidence between recently transmitted pulses and received pulses near the detector) is found to be a constraint for the repetition rates higher than 20 kHz, due to, overlapping with photons returning from a satellite with...

This article is a herald of our Book 3 devoted to good ICT (Information and Communication Technology) design implementation practices gained during design and development of the Polish pioneering Computer Control Systems destined for the Steel-Bar Mill of a Warsaw Metallurgical Plant in Warsaw and for the Michelson Interferometer of the Nicolas Cop...

This publication examines the influence of amplifiers and antenna mismatch on an ultra-wideband pulse. Using a state of the art ultra-wideband chip and an external power amplifier, we analyzed the impact of gain compression on the estimated channel impulse response. In addition, the impact of multiple reflections between a mismatched antenna and th...

In the near future the demand of wireless communications will elevate tremendously. The rapid increasing number of mobile end devices will require a much higher data rate connection than nowadays e.g. to smart homes (Internet of Things, IoT) or to the Internet. The radiation power pattern of base stations and mobile end devices will completely chan...

Testing of automotive radar systems is mandatory to provide high safety standards in automated and autonomous driving systems. Full vehicle tests with a ready to drive car are often carried out on automotive dyno test rigs. To test the radar sensor within the whole system a radar target stimulator can be used to save space and ensure reproducibilit...

-The Chirp-Z transformation is a versatile tool for frequency-time domain transformation. Though this versatility introduces a non-consistent scaling of the transformation products for which the standard implementation of the transformation does not account for. In this contribution we present a scaling factor that can be applied to the signal to a...

Free space optics (FSO) is a wireless optical communication technology enabling extremely high data transmission rates, which can be used for a wide range of emerging applications. Nevertheless, FSO system reliability can be easily deteriorated in the presence of various weather-induced disruptions. The main two atmospheric effects influencing FSO...

Heavy rain, dense fog, snow, extreme temperatures and moving objects represent a few examples of environmental conditions, which have a significant influence on reliable communications over wireless networks. In particular, a wireless link is vulnerable to precipitation or to fluctuations caused by reflections of signals from moving objects. Wirele...

Each of the various methods for mixed-mode load-pull measurements, which can be found in literature, has its own advantages and disadvantages. In this publication, we analyze two of the most commonly used setups and a third setup of which we provided an initial treatment in a previous publication. We investigated the impact of 180° hybrids on the t...

Various atmospheric effects have a negative influence on optical signals, especially in the troposphere, which must be taken into account in free space optical (FSO) communication systems. To obtain a quantitative estimate of these effects, different mathematical models are used, often based on empirical data from around the world. The main problem...

Current trends show that the demand for Internet bandwidth, especially regarding mobile end devices, is increasing significantly and will continue with an exponential growth in the future. In this regard, it is necessary to provide new technologies to meet the bandwidth requirements. In particular, the technology standard 5G and others are being pr...

The significance of the multiple advantages of the terrestrial FSO links decreases due to fact that their performance depends strongly on the atmospheric conditions. A commonly used way to counterbalance the effects of such phenomena is the employment of hybrid systems, which are using both the optical wireless technology and the millimeter waves a...

The interest for the optical wireless communication systems increases significantly the last years due to the very high advantages of this technology. More specifically, the FSO links can achieve very high data rate and secure communications with low installation and operational cost. However, the main disadvantage of the FSO links is that their pe...

This article presents simulation studies of elastic optical switching fabrics. Simulation experiments were conducted using the software developed by the authors. The simulator allows one to determine the loss probability for individual traffic classes offered to a single optical network node. The node architecture of elastic optical networks is bas...

This article proposes an analytical method for determining the traffic characteristics of multi-service switching networks in elastic optical networks. The method takes into consideration the limitations of W-S-W (wavelength-space-wavelength) switching networks in the execution of multi-slot connections in line with the concept of elastic optical n...

In recent years several distinct methods for mixed-mode load-pull measurements have been proposed. These methods use different ways of connecting impedance tuners to the device under test. In this contribution three of these approaches are analysed analytically and compared to each other. One of them is proposed, for the first time, in this paper....

Dependable communication is a cornerstone for industrial IoT applications. In hostile environments it is challenging to achieve a robust wireless communication link. This work investigates how the robustness of wireless communication can be improved by optimizing the design of antennas as well as the position of the antennas and sensors in the envi...

Future ground to deep space communication systems should support Gbps data links, which are resilient to atmospheric impairments. An alternative and in the same time complementary to the conventional RF technology is the emerging deep space Free Space Optical (FSO) system, which can successfully face the challenge. Aligned with this future possibil...

Deep space Free Space Optical (FSO) systems are an emerging technology, characterized with very high performance in terms of information capacity and communication distances. However, this novel technology demands preliminary experiments, which are unmanageable in real conditions. Regarding this issue, an innovative approach for testing deep space...

Autonomous vehicles are sophisticated self-sufficient systems which employ hundreds of sensors. To improve road safety, the number of Advanced Driver Assistance Systems (ADAS) steadily increases. Consequently, the applied systems are growing in complexity and connectivity. The network architecture within vehicles, however, is only adapted and exten...