Abstract-Scenario modules, ray-tracing simulations and analysis of millimetre wave and terahertz channels for smart rail mobility

Ke Guan,  Bo Ai,  Bile Peng,   Danping He,  Xue Lin,  Longhe Wang, Zhangdui Zhong, Thomas Kürner

https://ieeexplore.ieee.org/document/8319730/

Millimeter wave (mmWave) and Terahertz (THz) technologies are the enabler of providing high-data rate communications for `smart rail mobility'. In this paper, six scenario modules for mmWave and THz train-to-infrastructure channels are defined and constructed. All the main objects, such as tracks, stations, crossing bridges, tunnels, cuttings, barriers, pylons, buildings, vegetation, traffic signs, billboards, trains, etc., are modeled according to the typical geometries and materials in reality. The three-dimensional (3D) models of these six modules are publicly available and freely downloadable. Furthermore, extensive ray-tracing simulations in the 60 GHz band with 8 GHz bandwidth are made in all the six modules with two antenna setups. Path loss exponent, shadow factor, Ricean K-factor, root-mean-square (RMS) delay spread, and coherence bandwidth are extracted and analyzed. These channel characteristics show that the objects that might not be so impacting on lower frequency channels indeed influence mmWave channel properties, and therefore, they can even play a more important role in the channels at higher frequency bands - THz. The channel characteristics analyzed in this study provide the foundation for future work that aims to streamline the design, simulation, and development of mmWave and THz communications enabling smart rail mobility.

Abstract-Stochastic Channel Modeling for Kiosk Applications in the Terahertz Band

Danping He,  Ke Guan, Alexander Fricke, Bo Ai, Ruisi He,   Zhangdui Zhong,  Akifumi Kasamatsu,  Iwao Hosako, Thomas Kürner

http://ieeexplore.ieee.org/document/7982699/

Terahertz (THz) Kiosk application offers ultrahigh downloads of digital information to users’ handheld devices. System configuration and multiple paths between the transmitter and receiver have important impact on the achievable data rates. In this paper, the propagation channel of THz Kiosk downloading application is investigated and a stochastic channel model is proposed. Based on channel measurements using a vector network analyzer, a 3-D ray-tracing simulator is calibrated to conduct simulations for an in-depth analysis of the different channel characteristics. Successively, the observed propagation paths are classified and the key channel parameters in time, frequency, and spatial domains are modeled for each type of ray. The resulting stochastic model is evaluated in terms of Rician K-factor and root mean square delay spread. Compared to the reference data, the mean absolute errors of these two metrics of the three investigated scenarios are less than 1.48 dB and 0.07 ns, respectively. The results show that the target 100 gigabits per second data rate is achievable at tens of gigahertz system bandwidth at proper communication distance and higher order modulation schemes. The developed channel model allows system design engineers to generate realizations of propagation channel efficiently for designing Kiosk-fashion close-proximity communication systems in the THz band.

Abstract-Three-Dimensional Angle of Arrival Estimation in Dynamic Indoor Terahertz Channels Using a Forward–Backward Algorithm

Bile Peng, Thomas Kürner,

http://ieeexplore.ieee.org/document/7539586/

A novel angle-of-arrival (AoA) estimation method for both azimuth and elevation based on Bayesian inference and statistical state transition probabilities is presented for the dynamic indoor terahertz (THz) channel. A precise AoA estimation is crucial for the deployment of a directive antenna, which can compensate for the high path loss and reduce the intersymbol interference. In many application scenarios, the user equipment is moved by the user during the data transmission, and the AoA is not constant. The novel algorithm exploits the fact that the AoA movement can be represented as a Markov process and that the Bayesian inference can be used to combine the likelihood and a priori information to provide a more precise estimate than using the likelihood alone. An indoor human movement model is developed to generate the realistic application scenario and obtain the statistical transition probabilities. The forward–backward algorithm is implemented to carry out the Bayesian inference. The algorithm performance is illustrated using the channel models generated by a ray launching simulator. The background log-likelihood is suggested to adapt the algorithm to the instant channel state change in a multipath environment.

Cover Letter for the Special Issue on THz Communications

Cover Letter for the Special Issue on THz Communications
J Infrared Milli Terahz Waves
DOI 10.1007/s10762-015-0143-y
http://paperity.org/p/58836464/cover-letter-for-the-special-issue-on-thz-communications
Thomas Kürner

Received: 2 January 2015 /Accepted: 6 January 2015
# Springer Science+Business Media New York 2015

THz communications has made significant progress over the last years. Whereas propagation studies and general considerations of system characteristics have been in the focus in the first years of this emerging new research area, enabling transmitter and receiver technologies have been developed recently in various research laboratories all over the world. These advances have drawn the attention of the industry and yield to the formation of the IEEE 802.15 Task Group 3d targeting a standard for 100 Gbps switched point-to-point links including physical layer solutions around a carrier frequency around 300 GHz.
 This special issue on THz communications consists of 7 invited contributions, which are enumerated below. These contributions can be considered as a representative cross-section of ongoing research in this area.

1. THz-TDS Characterization of the Digital Communication Channels of the Atmosphere and the Enabled Applications by Y. Yang, M. Mandehgar and D. Grischkowsky from Oklahoma State University (United States) provide measurements and linear dispersion theory calculations for digital THz ground links.
2. Experimental Comparison of Terahertz and Infrared Signaling in controlled atmospheric Turbulence by J. Ma, J. F. Federici from the New Jersey Institute of Technology (United States) and L. Moeller from Bell Laboratories/Alcatel Lucent (United States) presents a
comparison of numerical simulations and experiments of IR and THz attenuation under different turbulence conditions.
3. Measurements and Modeling of Basic Propagation Characteristics for Intra-Device
Communications at 60 GHz and 300 GHz by T. Kürner, A. Fricke, S. Rey from Technische Universität Braunschweig (Germany), P. Le Bars , M. Achir from Canon
Research Center France (France) and T. Kleine-Ostmann from Physikalisch-Technische Bundesanstalt (Germany) describes propagation investigations targeting ultra-high datarate wireless links inside devices.
4. Ultrahigh-Bitrate Wireless Data Communications via THz-Links: Possibilities and Challenges by. T. Schneider from Technische Universität Braunschweig (Germany) describes a method for the generation of very stable and precise millimeter and THz waves.
5. Coherent Terahertz Wireless Signal Transmission using advanced Optical Fiber Communication Technology by A. Kanno, T. Kuri, I. Morohashi, I. Hosako, T. Kawanishi from NICT (Japan), Y. Yoshida and K. Kitayama from Osaka University (Japan) demonstrates multilevel modulation and demodulation applicable as a high-speed wireless transmission link directly connected to an optical fiber network.
6. THz Communications using Photonics and Electronics Devices: the Race to Data-Rate by G. Ducournau, P. Szriftgiser, F. Pavanello, E. Peytavit, M. Zaknoune, D. Bacquet, A.
Beck, T. Akalin and J.F. Lampin from Université de Lille (France) presents the design of a photonic-based THz emitter and its applications to communication links at 200, 400 and 600 GHz.
7. 64 Gbit/s Transmission over 850m Fixed Wireless Link at 240 GHz Carrier Frequency by I. Kallfass, F. Boes, T. Messinger, J. Antes from Universität Stuttgart (Germany), A. Inam
from Fujitsu Semiconductor Europe GmbH (United Kingdom), U. Lewark from Karlsruher Institute of Technology (Germany), A. Tessmann from Fraunhofer Institute of Applied Solid State Physics in Freiburg (Germany) and R. Henneberger from Radiometer Physics in Meckenheim (Germany) demonstrates a successful multi-gigabit transmission based on monolithic integrated circuits and 64 GSa/s ADC and DAC boards.
____________________
T. Kürner (*)
Institut für Nachrichtentechnik, THz Communications Lab, Technische Universität Braunschweig,
Schleinitzstr. 22, 38092 Braunschweig, Germany

e-mail: t.kuerner@tu-bs.de

Abstract-Measurements and Modeling of Basic Propagation Characteristics for Intra-Device Communications at 60 GHz and 300 GHz

Thomas Kürner, 

Alexander Fricke, 

Sebastian Rey, 

Philippe Le Bars, 

Achir Mounir, 

Thomas Kleine-Ostmann

http://link.springer.com/article/10.1007/s10762-014-0117-5

Multi Gigabit wireless links using millimeter or sub millimeter waves have become of interest to replace wired connections within devices. In order to develop and simulate the corresponding systems, propagation and channel models for intra-device environments are required. This paper describes first results from measurement campaigns carried out at 60 GHz and 300 GHz in such environments. In a first step reflection and transmission properties of typical plastic materials used within devices have been measured and modeled using the Transfer Matrix Method. In a second step propagation characteristics in wave-guide like structures have been measured and modeled using ray tracing.