Sebastian Sczyslo

Hybrid localization using UWB and inertial sensors

In this paper we propose a hybrid localization system combining an Ultra-Wideband localization system with inertial sensors. Algorithms for dead reckoning as well as the fusion of data provided by the UWB system and the inertial sensors are presented. Finally experimental results are shown.

Determination of the delay spread of an indoor channel measurement campaign in the UHF band

This contribution deals with the determination of the delay spread of the indoor channel within a large exhibition hall. The results are of special interest to Programme Making and Special Event applications, intending to operate in this typical scenario, and are representative for other applications within the entire UHF range. To determine the delay spread an ultra-wideband measurement campaign is carried out. Both the small scale as well as the large scale setup of the campaign are introduced in this paper.

Determination of the impulse response of UWB antennas using GTEM cells

This paper deals with a measurement method to determine the absolute impulse response of ultra-wideband (UWB) antennas. At this the antenna is placed into the testing volume of a gigahertz transverse electromagnetic (GTEM) cell, augmenting the use-case of this well-known EMC measurement device. The unit consisting of cell and antenna is excited by an UWB pulse. The chief attraction is that the impulse response of the GTEM cell can be modeled by a dirac distribution within a distinct time interval, so that within this interval an approximately plane TEM wave impinges on the antenna under test without being dispersively distorted by parasitic multimode wave propagation. Hence, the impulse response of a receiving antenna can exclusively be obtained within this distinct time interval, if further constraints, like maximal antenna size or estimated impulse response length are carefully adapted to the cells properties. In order to verify the proposed method, it is applied to a UWB cone antenna and measurement results are compared with those derived from the two antenna method, a reference measurement incorporating two equally shaped antennas, as well as from simulations.

UWB Performance of Coplanar Tapered Slot Antennas

The ultrawideband (UWB) performance and impulse response parameters of tapered slot antennas with different flares opening rates and taper types fit to a stepped quarter-wave Chebyshev transformer are presented. This transformer is used to maximize the impedance bandwidth and power transfer gain. Different smoothing tapers are used to optimize impulse response parameters. The antennas were designed for 1-3 GHz frequency range, and the substrate is Duroid with a dielectric constant 6.15.

Distance-dependent enhancement of a measurement based channel model for large concert halls

This paper extends a previously presented indoor channel model for large concert halls. The enhancement includes large scale variations of wireless propagation channels inside of a typical scenario specifically intending for Cognitive Programme Making and Special Event applications (C-PMSE). Because of the frequency agile nature of a cognitive radio link, the statistical model is realized as a baseband multipath model in the time domain derived from an ultra wideband measurement campaign focusing on line of sight propagation channels.

Transient UWB antenna characterization in GTEM cells

This contribution presents a novel measurement approach to characterize the pulse reception behavior of UWB antennas using a GTEM cell. By evaluating the respective reception properties the transmit characteristics are calculated via the Lorentzs reciprocity theorem. The cell is excited at its feeding port by an UWB pulse covering a frequency range up to 10 GHz. The antenna is placed inside the testing volume. Due to the fact, that pure TEM propagation predominates within a distinct time interval, electrical small antennas can be characterized with a negligible influence of either field distortion or pulse dispersion effects. Hence, the time-gated receive signal of the antenna can be used to compute the impulse response directly via deconvolution of the incident electric field and the voltage at the antennas feeding port.

A novel simulation system for the performance evaluation of 3GPP LTE system in indoor scenarios

This article introduces a novel distributed simulation system for diverse simulation tasks of communications systems. With the help of its parallel distributed structure and outstanding computing power, many computationally expensive simulations can be completed in an acceptable duration. Moveover, its cooperative infrastructure is suitable for simulation tasks in multiuser scenarios or other tasks in a closed loop system. In this contribution, the general platform is applied to predict the downlink performance of a 3rd generation partnership project (3GPP) long-term-evolution (LTE) system in an indoor scenario. To achieve the required channel impulse responses (CIRs) a commercial ray tracing tool named dasiawireless insitepsila from Remcom is used. Finally two different methods to obtain the throughput are compared, first one based on the signal to noise ratio and second one based on the full channel impulse response information.

On the fidelity of ultra-wideband antennas

Within this contribution two ultrawideband antennas, an almost omnidirectional bi-conical antenna of type SBA 9113 from Schwarzbeck and a directional Vivaldi antenna, are analyzed according to their time-domain characteristics. In this context the fidelity factor and the peak value play an important role. Hence both, the parameters definition is recaped and the particular practical meaning is explained. Moreover, a new parameter, the two antenna fidelity is introduced which indicates an antennas performance in context of a typical point to point link involving two antennas. To increase the accuracy the analysis is based upon a resimulation of both antennas.

Transient radiation properties of tapered slot antenna

Tapered slot antenna tapers were designed using Chebyshev transformer to minimize reflection and maximize power transfer of the antenna. Cubic spline and exponential curves were fit to the designed steps to smooth the steps. Impulse response for the designed tapers were extracted through the MATLAB code from the simulated broadband farfield data in the CST MWS software.

A 2-dimensional filter for UWB-localization in NLoS scenarios using BeamLoc

This paper deals with the simulation of an Ultra-wideband localization algorithm using a raytracer. A 2-dimensional filter is proposed and analyzed due to its capabilities to recover the Angle of Arrival in a Non-Line of Sight scenario. Moreover, it is shown that the filter enables to increase the Signal to Noise Ratio significantly.