Article
Engineering, Electrical & Electronic
Ke Guan, Danping He, Bo Ai, Yi Chen, Chong Han, Bile Peng, Zhangdui Zhong, Thomas Kuerner
Summary: This paper characterizes the smart rail mobility channel through UWB channel sounding and ray tracing, extracting various channel characteristics and studying the performance of THz communication in different settings. The results provide insights into system design and evaluation for THz communication enabled Smart Rail Mobility.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Ke Guan, Bile Peng, Danping He, Johannes M. Eckhardt, Haofan Yi, Sebastian Rey, Bo Ai, Zhangdui Zhong, Thomas Kuerner
Summary: To achieve the vision of smart rail mobility, high-data rate wireless connectivity with up to dozens of gigahertz bandwidth is required, which drives the exploration of underutilized millimeter wave (mmWave) and sub-mmWave bands. In this study, the wireless channel within a smart rail mobility scenario is characterized through ultrawideband (UWB) channel sounding and ray tracing (RT) at mmWave and sub-mmWave bands, providing a more thorough understanding of the intrawagon mmWave and sub-mmWave channels.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Yuanbo Li, Yi Chen, Dong Yan, Ke Guan, Chong Han
Summary: To support intelligent vehicular services, high-speed communications from vehicles to infrastructure (V2I) are needed in vehicular ad-hoc networks (VANET). The Terahertz (THz) band, which has abundant spectrum resources, is considered promising for this purpose. However, channel modeling for THz V2I communications is a challenge. In this paper, ray-tracing techniques are used to analyze the V2I channel at 300 GHz in an urban scenario, and a novel ray-tracing assisted stochastic channel model (RTA-SCM) is proposed.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Optics
Yifan Zhu, Qingfeng Ding, Lanyong Xiang, Jinfeng Zhang, Xinxing Li, Lin Jin, Shangguan Yang, Jiandong Sun, Hua Qin
Summary: To meet the demand for broadband and high-sensitivity terahertz detectors, a broadband terahertz detector built with antenna-coupled AlGaN/GaN HEMTs was designed. The detector exhibits a continuous response spectrum in the range of 0.2 to 2.0 THz at 298 K and 0.2 to 4.0 THz at 77 K when exposed to incoherent terahertz radiation. Sensitivity was characterized under coherent terahertz irradiation, with noise-equivalent power (NEP) ranging from 188 pW/Hz at 298 K to 19 pW/Hz at 77 K, achieved at different frequencies.
Article
Engineering, Civil
Mahdi Saki, Mehran Abolhasan, Justin Lipman, Abbas Jamalipour
Summary: In this paper, a novel mobility model is proposed to provide real-time train traffic traces for train-to-train communication models. The model works based on trip timetables without relying on GPS, making it a practical solution for urban areas or tunnels with poor or unavailable GPS signal. The proposed model also incorporates an energy optimization function to guide trains towards efficient operation, and an algorithm to determine contact specifications between trains for data exchange capacity estimation.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2022)
Article
Green & Sustainable Science & Technology
Amparo Moyano, Carlos Tejero-Beteta, Santos Sanchez-Cambronero
Summary: This paper analyzes the challenges that railway operators face when implementing new MaaS applications on a national scale and evaluates the factors influencing the successful implementation of MaaS in cities with high-speed rail services. These factors are directly related to adapting MaaS services to different geographies, from large metropolitan areas to small cities in rural environments. The analysis fills a gap in the literature and sparks a debate about different approaches and transport policies that rail operators could adopt in the MaaS environment.
Article
Engineering, Electrical & Electronic
Yi Chen, Yuanbo Li, Chong Han, Ziming Yu, Guangjian Wang
Summary: This study investigates the indoor channel characteristics of THz communications by conducting extensive channel measurement activities and studying hybrid channel models. Through careful system calibration, MPC clustering, and ray-tracing techniques, the research comprehensively analyzes the propagation features and multi-path characteristics of THz signals.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2021)
Article
Computer Science, Information Systems
Santiago Figueroa-Lorenzo, Jon Goya, Javier Anorga, Inigo Adin, Jaizki Mendizabal, Saioa Arrizabalaga
Summary: The European Union is moving towards smart mobility and Mobility as a Service, with a focus on security in the railway sector. The integration of IoT sensors and the development of an alarms collection system based on Ethereum blockchain events-log aim to ensure both entity security and information privacy.
IEEE INTERNET OF THINGS JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Jan Fikejz, Antonin Kavicka
Summary: This article introduces a solution concept based on the worldwide-recognized GNSS system and an original rail network data model for identifying the current position of rail vehicles. It also explores the use of this concept as supplementary support for regional rail traffic control. The solution includes algorithms for position identification and evaluation of mutual positions of multiple trains, as well as automatic network model-building from the railway infrastructure database. Verification results demonstrate the applicability of the proposed solution for real traffic control support.
APPLIED SCIENCES-BASEL
(2022)
Article
Telecommunications
Zheng Lin, Lifeng Wang, Jie Ding, Bo Tan, Shi Jin
Summary: This paper presents a novel solution for channel power gain estimation in THz vehicle-to-infrastructure (V2I) networks using leaky-wave antennas, based on conditional generative adversarial networks (GAN). Simulation results confirm that our solution can accurately estimate the channel power gains at a fast speed versus the THz frequencies.
IEEE COMMUNICATIONS LETTERS
(2023)
Article
Information Science & Library Science
A. Paula Rodriguez Muller, Amandine Lerusse, Trui Steen, Steven Van de Walle
Summary: Public service producers are investing heavily in new digital channels for user engagement in citizen sourcing efforts, but users still prefer traditional and e-government channels over new mobile government channels. This study explores users' reporting behavior, finding that the digital divide, service experience, and channel satisfaction play significant roles in users' channel choice.UserService membership and satisfaction with mobile applications impact user-reporters' preference for traditional and e-government channels, informing public service producers on how to enhance public service delivery.
GOVERNMENT INFORMATION QUARTERLY
(2021)
Article
Green & Sustainable Science & Technology
Jinghui Wang, Ahmed Ghanem, Hesham Rakha, Jianhe Du
Summary: The paper introduces a continuous rail transit simulator (RailSIM) for multi-modal energy-efficient routing applications, demonstrating its capabilities in simulating train dynamics, energy consumption, and matching railway schedules through calibration and validation. It also explores the potential of RailSIM in enhancing energy-efficient travel.
INTERNATIONAL JOURNAL OF SUSTAINABLE TRANSPORTATION
(2021)
Article
Green & Sustainable Science & Technology
Davide Maria Bruno, Guido Musante, Fabio Dacarro
Summary: This paper presents a case study and research hypothesis of a project developed by the authors for the city of Gwangmyeong in South Korea. The project aims to promote social integration between different parts of the city through an innovative public transportation system, addressing a crucial problem in contemporary society. The infrastructure of the project serves as a social connective tissue, providing more sustainable living conditions.
Article
Engineering, Civil
Zhendong Liu, Mats Berg, Anders Ekmark
Summary: This study investigates the formation of power peaks and explores power peak shaving concepts in order to make existing systems more reliable and accommodate more freight traffic. Different from previous studies focusing on energy saving, this research aims at lowering power peak demand through smart train operation. The study shows a compromise between power peak shaving and energy saving, calling for more attention in future studies.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART F-JOURNAL OF RAIL AND RAPID TRANSIT
(2022)
Article
Chemistry, Physical
Qingzhi Meng, Qijing Lin, Feng Han, Weixuan Jing, Yangtao Wang, Zhuangde Jiang
Summary: This paper proposes and fabricates a double-channel GaN/AlGaN HEMT as a THz detector, achieving higher responsivity and lower noise equivalent power compared to single-channel detectors, showing promising practical applications.
Article
Astronomy & Astrophysics
Johannes M. Eckhardt, Christoph Herold, Bo Kum Jung, Nils Dreyer, Thomas Kuerner
Summary: This article presents a modular link level simulator for the physical layer of beyond-5G and 6G wireless communication systems in the THz range. The simulator is validated and applied to a wirelessly augmented data center, showing that a LOS condition and sufficient transmit power are essential in the low THz range.
Article
Engineering, Electrical & Electronic
Hongyang Du, Jiayi Zhang, Ke Guan, Dusit Niyato, Huiying Jiao, Zhiqin Wang, Thomas Kuerner
Summary: The article introduces RIS-aided THz communications using reconfigurable intelligent surface technology. It accurately models the small-scale amplitude fading of THz signals through signal measurement experiments and optimizes the phase-shifts at RIS elements using a swarm intelligence-based method. Statistical characterizations of SNDR and SNR are derived, and asymptotic analysis is conducted to gain insights. Analytical expressions for outage probability and ergodic capacity are also derived, showing that increasing the number of RIS elements can significantly improve system performance.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Zhuangzhuang Cui, Ke Guan, Claude Oestges, Cesar Briso-Rodriguez, Bo Ai, Zhangdui Zhong
Summary: This paper focuses on the cluster-based characterization and modeling of air-to-ground (AG) propagation channels for unmanned aerial vehicles (UAVs) integrated with wireless communication. It proposes a novel cluster-based AG channel model and validates its accuracy.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Astronomy & Astrophysics
Pengxiang Xie, Ke Guan, Danping He, Haofan Yi, Jianwu Dou, Zhangdui Zhong
Summary: Terahertz (THz) communications are critical for future wireless communication. This study investigates the scattering propagation characteristics on rough surfaces using a full-wave simulation method. The results show that scattering becomes a significant propagation mechanism with increased roughness, and the depolarization effect is more severe for rougher surfaces. The findings are important for accurate THz channel modeling and the design of THz communication systems.
Article
Engineering, Electrical & Electronic
Tobias Doeker, Christoph Herold, Johannes M. M. Eckhardt, Thomas Kurner
Summary: Low terahertz frequencies are potential candidates for future wireless communication systems. Despite the high path losses, highly directive antennas can be used to compensate for the losses, making eavesdropping challenging. This article evaluates eavesdropping possibilities by investigating the scattering properties of common office objects, such as a coffee cup, a thermos, and a laptop. The results show that eavesdropping opportunities are good when a thermos is used, while for other objects, direct eavesdropping results in lower secrecy capacity in most cases.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Yuanbo Li, Yi Chen, Dong Yan, Ke Guan, Chong Han
Summary: To support intelligent vehicular services, high-speed communications from vehicles to infrastructure (V2I) are needed in vehicular ad-hoc networks (VANET). The Terahertz (THz) band, which has abundant spectrum resources, is considered promising for this purpose. However, channel modeling for THz V2I communications is a challenge. In this paper, ray-tracing techniques are used to analyze the V2I channel at 300 GHz in an urban scenario, and a novel ray-tracing assisted stochastic channel model (RTA-SCM) is proposed.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Xiping Wang, Ke Guan, Danping He, Zhao Zhang, Haoyang Zhang, Jianwu Dou, Zhangdui Zhong
Summary: This article proposes a super-resolution (SR) model based on multitask learning convolutional neural networks for recovering high-resolution channel characteristics from sparse sampling data. Experimental results show that the model achieves good performances and outperforms other deep learning models. Visualization of SR performances also demonstrates the advantages of the proposed model. The necessity of data augmentation and techniques in model design is proved through ablation study. The good generalizability of the proposed model leads to discussions of potential applications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Civil
Danping He, Ke Guan, Bo Ai, Zhangdui Zhong, Junhyeong Kim, Heesang Chung, Andrej Hrovat
Summary: This study focuses on the channel measurements and ray-tracing simulations for frequency modulated continuous wave (FMCW) automotive mmWave radar. By proposing a measurement-based electromagnetic parameter estimation method, the issue of lacking reliable material parameters for RT simulation at 77 GHz frequency band is addressed. The simulations are validated in various domains, allowing for more reliable channel testing in different environments and configurations.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Engineering, Civil
Xiyu Wang, Danping He, Ke Guan, Hongyu Duan, Jianwu Dou, Najah Abed Abuali, Zhangdui Zhong
Summary: This paper investigates the propagation channel characteristics of mmWave automotive radar and proposes a hybrid channel model that combines ray-tracing (RT) and stochastic modeling techniques. The hybrid model improves simulation efficiency and allows for virtual testing in various complex environments.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Engineering, Civil
Dong Yan, Ke Guan, Danping He, Junhyeong Kim, Heesang Chung, Dao Tian, Zhangdui Zhong
Summary: This paper comprehensively studies the impact of road bridge blockage effects on mmWave vehicle-to-infrastructure (V2I) links and proposes an empirical model that can accurately characterize the bridge blockage effect. The proposed Single Road Bridge (SRB) model can make the mean absolute error (MAE) and root mean square error (RMSE) within 5 dB, which is of great value for accurately simulating real-world road bridge blockage events when designing future Intelligent Autonomous Transportation Systems (IATS).
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Engineering, Electrical & Electronic
Johannes M. Eckhardt, Alper Schultze, Ramez Askar, Tobias Doeker, Michael Peter, Wilhelm Keusgen, Thomas Kuerner
Summary: In this paper, researchers present a uniform and collaborative data evaluation method for measurement sets from two different time-domain channel sounders. By extracting discrete multipath components, the properties of the propagation channel are analyzed. The impact of a realistic antenna array on the radio channel for the communication system is examined. The extracted multipath components are published as research data to serve future analytical studies and simulations in relevant scenarios for the sixth generation of mobile systems.
IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Lina Wu, Danping He, Bo Ai, Jian Wang, Ke Guan, Zhangdui Zhong, Dongliang Liu, Fusheng Zhu
Summary: Satellite image based land cover classification is critical for global and environmental applications, and deep learning has been proven to be excellent in semantic segmentation. However, traditional neural networks easily lose image information and it is difficult to distinguish adjacent land cover classes with similar colors. In order to improve inter-class distinguishability, a Canny enhanced high-resolution neural network (C-HRNet) is proposed based on Canny edge features and the high-resolution neural network (HRNet). Experimental results show that C-HRNet outperforms state-of-the-art semantic segmentation networks in large-scale fine-grained scenarios.
IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Fawad Sheikh, Andreas Prokscha, Johannes M. Eckhardt, Tobias Doeker, Naveed A. Abbasi, Jorge Gomez-Ponce, Benedikt Sievert, Jan Taro Svejda, Andreas Rennings, Jan Taro Svejda, Jan Barowski, Christian Schulz, Ilona Rolfes, Daniel Erni, Andreas F. Molisch, Thomas Kuerner, Thomas Kaiser
Summary: This article traces the progress of THz measurements, antennas and simulations, from historical milestones to the current state of research and provides an outlook on the remaining challenges.
IEEE JOURNAL OF MICROWAVES
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Johannes M. Eckhardt, Christoph Herold, Bo Kum Jung, Thomas Kuerner
Summary: This paper analyzes the physical layer characteristics of a wireless backhaul network in Berlin through ray-optical channel predictions and link-level simulations.
2022 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Christoph Herold, Tobias Doeker, Johannes M. Eckhardt, Thomas Kurner
Summary: Wireless communications in the THz range are expected to provide high data-rate transmissions due to the large available bandwidth. While they are inherently more robust against eavesdropping attacks, this paper shows that even common objects can significantly influence wave propagation at 300 GHz and provide opportunities for eavesdropping signals.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
