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Based on Vector Network Analyzer (VNA) Measurements, a model for the specular reflection behavior of printed circuit boards (PCB) in the Terahertz range has been derived. It has been calibrated to suit the behavior of the measurements using a simulated annealing algorithm. The model has been tailored for integration to ray-tracing based propagation modeling.
Channel Impulse Responses (CIR) have been measured in the 300 GHz frequency range inside a mock-up for two different operational modes. The peculiarities of LOS vs. NLOS communications are discussed and the CIRs are interpreted accordingly to serve as a guidance to the features of the complete intra-device propagation channel.
Along with the steady increase of data rates in communication applications, the utilized bandwidths are growing accordingly, thus requiring higher carrier frequencies in face of the almost entirely occupied spectrum in the mm wave range and below. Therefore, channel measurements up to the lower THz frequency range are necessary for the development of modern and future communication systems. In this...
For the modeling and design of communication systems in the lower THz frequency range the propagation conditions need to be known. We show a comparison of ultra broadband channel measurements from 50 GHz to 325 GHz in different scenarios related to typical office and industry environments.
This paper investigates the propagation measurement conducted in a vegetated residential environment. In [1], the theoretical modeling of a propagation prediction model in vegetated residential environments was presented. The model extends the Walfisch-Bertoni urban and the COST-231 Walfisch-Ikegami model for application in vegetated residential environments. In this paper, we further verify the proposed...
Allowing for the conception of future THz indoor communication systems, a simulation environment combining an accurate ray tracing propagation model as well as a physical layer simulator is introduced. Frequency domain ray tracing is demonstrated for a wireless LAN setup in an indoor environment at frequencies from 300 to 350 GHz. On the basis of the results, arising challenges of such ultra broadband...
Due to the growing demand for bandwidth the tendency to employ higher frequencies up to the THz range has increased in the last few years. Yet, for implementing future THz communication systems, adequate test and characterization measurements are essential. In this paper we present channel propagation measurements in a typical office environment covering the wide frequency range from 50 GHz up to...
Indoor wireless communication channels will be operated in the 60 GHz band soon and will work at 300 GHz and beyond in the foreseeable future. Although diffraction occurs at a multitude of objects in indoor environments and needs to be considered for reliable propagation simulations, very few work exists on this topic in the mm and sub-mm wave bands. Here, we present measurements of the diffraction...
The constantly growing need for unoccupied and unregulated bandwidth will lead to the extension of operation frequencies of ultrabroadband communication systems into the lower Terahertz frequency range. Here we present first channel measurements at 300 GHz for two simple indoor scenarios, a point-to-point link on a desktop and a connection from a desktop to an access point within an office room. For...
Satellite positioning accuracy is degraded by multipath propagation between satellite and the receiver. In this paper we give an overview of a new approach to model and correct this impairment, and present some preliminary results. High accuracy 3D laser scanning is utilized to model the environment. This gives an accurate basis for the characterization of the satellite to earth radio channel by using...
This paper reports on the outdoor-to-indoor propagation measurements for broadband wireless access systems in rural areas. The study is based on measurements conducted at seven selected residential buildings in a rural area where two WiMAX OFDMA systems (IEEE 802.16e), operated at 825 MHz and 3500 MHz, were individually erected on towers of 25 m above ground in the north-west area of Hetzwege, Germany...
This paper presents the human blockage model based on the authors' work in the framework of the IEEE 802.11ad 60 GHz channel model development. The human blockage model combines ray tracing simulations, an electromagnetic diffraction model and a random walk model for human movement. In addition to the stochastic model the impact of human blockage on wireless communications is analyzed.
In this paper, we present an approach for the modeling of non-specular scattering at rough surfaces in the THz frequency range by means of the Kirchhoff scattering theory. The practical implementation of the Kirchhoff model in a ray tracing algorithm is discussed. Ray tracing simulation results are compared with measurements for the purpose of validation. The size of the relevant active scattering...
In a vegetated residential area, a wireless system has the base-station transmitter located close to the surrounding rooftops, so that propagation takes place over the rooftops and through the canopy of the trees that are above the houses. For a receiving antenna on the street level, the propagation loss can be decomposed into three components namely free space, multi-screen diffraction and rooftop-to-street...
This paper presents the modeling of both coherent and incoherent scattering processes from rough surfaces at THz frequencies with the focus on polarization aspects. In a ray tracing algorithm, coherent scattering is implemented based on the Kirchhoff theory whereas a perturbation approach is used for the incoherent contribution. Geometrical depolarization is accounted for by means of the Jones calculus...
The signal-to-noise ratio (SNR) available at the receiver significantly affects the performance of Car-to-Car (C2C) communication systems. Thus, accurate models to predict the path loss, in particular for non-line-of-sight (NLOS) scenarios, are essential for the development of C2C systems. Since deterministic models are very time-consuming, also fast-computable stochastic models are of great interest...
Recently, analogue video signal transmission at 300 GHz has been demonstrated using a versatile Schottky mixer based measurement system designed for terahertz communication channel modelling and propagation studies. In this reported work, digital signal transmission at 300 GHz using this system is demonstrated and analysed. The performance of the digital transmission setup is characterised with respect...
Accompanied by the continuous progression of the maturity of car-to-x communication protocols and corresponding system architectures, the need for integrated network simulation approaches which consider realistic channel modeling on the one hand and appropriate mobility models on the other hand becomes more and more observable. Moreover, in order to analyze the impacts of car-to-x applications on...
This paper gives an overview of current issues in the field of mm-wave and THz communications. A concept for radio channel modeling is presented together with the latest channel investigation results in this frequency range. In addition we discuss the status quo of standardization activities and the worldwide ongoing spectrum allocation plans.
Cell outage management is a functionality aiming to automatically detect and mitigate outages that occur in radio networks due to unexpected failures. We envisage that future radio networks autonomously detect an outage based on measurements, from e.g., user equipment and base stations, and alter the configuration of surrounding radio base stations in order to compensate for the outage-induced coverage...
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