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BETA
Tenhunen, Hannu
Publications (10 of 85) Show all publications
Aslam, B., Azam, M. A., Amin, Y., Loo, J. & Tenhunen, H. (2019). A high capacity tunable retransmission type frequency coded chipless radio frequency identification system. International Journal of RF and Microwave Computer-Aided Engineering, 29(9), Article ID e21855.
Open this publication in new window or tab >>A high capacity tunable retransmission type frequency coded chipless radio frequency identification system
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2019 (English)In: International Journal of RF and Microwave Computer-Aided Engineering, ISSN 1096-4290, E-ISSN 1099-047X, Vol. 29, no 9, article id e21855Article in journal (Refereed) Published
Abstract [en]

This article presents a 12-bit frequency coded chipless RFID system in the frequency range of 3 to 6 GHz. The system consists of a fully printable chipless tag and a pair of high-gain reader antennas. The tag also incorporates its own antennas to improve the read range. Information is encoded into frequency spectrum using a multi-resonant circuit. The circuit consists of multiple microstrip U and L-shaped open stub resonators patterned in a unique configuration. The proposed configuration aids in capturing more data in a reduced space as well as tunable frequency operation. Tag and reader antennas utilize techniques such as stepped impedance feeding line, defective partial ground plane, and stair-step patch structure to achieve wide-band impedance bandwidth in miniature size. The results of the wireless measurements in the non-anechoic environment show that the proposed system has a reading range of more than 20 cm. The presented system possesses great potential for low-cost short-range inventory tracking.

Place, publisher, year, edition, pages
WILEY, 2019
Keywords
frequency coded, multi-resonant circuit, orthogonally polarized antennas
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-257542 (URN)10.1002/mmce.21855 (DOI)000478622300028 ()2-s2.0-85066137117 (Scopus ID)
Note

QC 20190924

Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-09-24Bibliographically approved
Aslam, B., Kashif, M., Azam, M. A., Amin, Y., Loo, J. & Tenhunen, H. (2019). A low profile miniature RFID tag antenna dedicated to IoT applications. Electromagnetics, 39(6), 393-406
Open this publication in new window or tab >>A low profile miniature RFID tag antenna dedicated to IoT applications
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2019 (English)In: Electromagnetics, ISSN 0272-6343, E-ISSN 1532-527X, Vol. 39, no 6, p. 393-406Article in journal (Refereed) Published
Abstract [en]

RFID tag antennas with stable performance on the diverse electromagnetic mounting platforms are an integral part of the ubiquitous RFID systems. This research article presents a novel tag antenna design that facilitates the said objective. The proposed antenna consists of a modified H-shaped slot structure that ensures considerable robustness from the application environment through confining the surface current density within the antenna structure. The antenna offers a tunable bandwidth of 40 MHz within the microwave band of (2.4-2.5) GHz. The proposed tag antenna exhibits excellent response on metallic platforms of different sizes and thicknesses with an effective gain of almost four times of that in free space. Furthermore, the designed tag antenna performs adequately well on low-medium permittivity dielectrics (glass, paper, and plastic) and RF absorbers (water). The free space and on-metal performance of the proposed tag antenna are verified by testing a prototype realized on the FR4 substrate.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Microwave band, internet of things (IoT), slotted patch, and impedance tuning
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-255555 (URN)10.1080/02726343.2019.1641654 (DOI)000476256100001 ()2-s2.0-85070852350 (Scopus ID)
Note

QC 20190814. QC 20191016

Available from: 2019-08-14 Created: 2019-08-14 Last updated: 2019-10-16Bibliographically approved
Khan, T., Rahman, M., Akram, A., Amin, Y. & Tenhunen, H. (2019). A Low-Cost CPW-Fed Multiband Frequency Reconfigurable Antenna for Wireless Applications. ELECTRONICS, 8(8), Article ID 900.
Open this publication in new window or tab >>A Low-Cost CPW-Fed Multiband Frequency Reconfigurable Antenna for Wireless Applications
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2019 (English)In: ELECTRONICS, ISSN 2079-9292, Vol. 8, no 8, article id 900Article in journal (Refereed) Published
Abstract [en]

A novel, cedar-shaped, coplanar waveguide-fed frequency reconfigurable antenna is proposed. The presented antenna uses low-cost FR4 substrate with a thickness of 1.6 mm. Four PIN diodes are inserted on the antenna surface to variate the current distribution and alter the resonant frequencies with different combinations of switches. The proposed antenna is fabricated and measured for all states, and a good agreement is seen between measured and simulated results. This antenna resonates within the range of 2 GHz to 10 GHz, covering the major wireless applications of aviation service, wireless local area network (WLAN), worldwide interoperability for microwave access (WiMAX), long distance radio telecommunications, and X-band satellite communication. The proposed antenna works resourcefully with reasonable gain, significant bandwidth, directivity, and reflection coefficient. The proposed multiband reconfigurable antenna will pave the way for future wireless communications including WLAN, WiMAX, and possibly fifth-generation (5G) communication.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
reconfigurable antennas, PIN diodes, wireless applications, fifth-generation (5G) communication
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-260200 (URN)10.3390/electronics8080900 (DOI)000483554300028 ()2-s2.0-85071854428 (Scopus ID)
Note

QC 20190930

Available from: 2019-09-30 Created: 2019-09-30 Last updated: 2019-09-30Bibliographically approved
Naqvi, S. I., Khan, A., Azam, M. A., Amin, Y., Loo, J. & Tenhunen, H. (2019). A planar flexible quad-band antenna for WLAN/WiMAX/LTE applications. In: 2019 2nd International Conference on Computing, Mathematics and Engineering Technologies, iCoMET 2019: . Paper presented at 2nd International Conference on Computing, Mathematics and Engineering Technologies, iCoMET 2019, 30 January 2019 through 31 January 2019. Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>A planar flexible quad-band antenna for WLAN/WiMAX/LTE applications
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2019 (English)In: 2019 2nd International Conference on Computing, Mathematics and Engineering Technologies, iCoMET 2019, Institute of Electrical and Electronics Engineers Inc. , 2019Conference paper, Published paper (Refereed)
Abstract [en]

In this work a quad-band, planar, low-profile and compact antenna envisioned for incorporation into portable wireless devices is presented. The antenna is modeled on flexible Rogers RT/Duroid 5880 substrate of 0.127mm thickness. The proposed antenna structure consists of symmetrically placed F-shaped slits and a curved rectangular shaped ground plane with a CPW feed line. The four bands obtained for the radiator operates at the resonant frequencies 2.8, 3.9, 5.45 and 6.2 GHz with impedance bandwidths of 14%, 14.5%, 5.7%, and 5% respectively. Thus the proposed antenna supports WLAN, LTE, WiMAX, and C-band applications. The peak gain achieved for the antenna is 3.4 dB.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2019
Keywords
C-Band, Flexible substrate, Quad-band antenna, WiMAX, Antenna feeders, Antenna grounds, Electric impedance, Mobile antennas, Natural frequencies, Slot antennas, Wireless local area networks (WLAN), Antenna structures, C-bands, Compact antenna, Impedance bandwidths, Portable wireless device, Quad-band antennas, Rectangular-shaped, Microwave antennas
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-255974 (URN)10.1109/ICOMET.2019.8673414 (DOI)2-s2.0-85064117327 (Scopus ID)9781538695098 (ISBN)
Conference
2nd International Conference on Computing, Mathematics and Engineering Technologies, iCoMET 2019, 30 January 2019 through 31 January 2019
Note

QC 20190815

Available from: 2019-08-15 Created: 2019-08-15 Last updated: 2019-08-15Bibliographically approved
Mohamed, S. A., Haghbayan, M.-H. -., Westerlund, T., Heikkonen, J., Tenhunen, H. & Plosila, J. (2019). A Survey on Odometry for Autonomous Navigation Systems. IEEE Access, 7, 97466-97486, Article ID 8764393.
Open this publication in new window or tab >>A Survey on Odometry for Autonomous Navigation Systems
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2019 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 97466-97486, article id 8764393Article in journal (Refereed) Published
Abstract [en]

The development of a navigation system is one of the major challenges in building a fully autonomous platform. Full autonomy requires a dependable navigation capability not only in a perfect situation with clear GPS signals but also in situations, where the GPS is unreliable. Therefore, self-contained odometry systems have attracted much attention recently. This paper provides a general and comprehensive overview of the state of the art in the field of self-contained, i.e., GPS denied odometry systems, and identifies the out-coming challenges that demand further research in future. Self-contained odometry methods are categorized into five main types, i.e., wheel, inertial, laser, radar, and visual, where such categorization is based on the type of the sensor data being used for the odometry. Most of the research in the field is focused on analyzing the sensor data exhaustively or partially to extract the vehicle pose. Different combinations and fusions of sensor data in a tightly/loosely coupled manner and with filtering or optimizing fusion method have been investigated. We analyze the advantages and weaknesses of each approach in terms of different evaluation metrics, such as performance, response time, energy efficiency, and accuracy, which can be a useful guideline for researchers and engineers in the field. In the end, some future research challenges in the field are discussed.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2019
Keywords
filter-based, GPS-denied, inertial odoemtry, laser odometry, loosely-coupled, optimization-based, Self-contained localization, tightly-coupled, visual-inertial odometry, wheel odometry, Energy efficiency, Sensor data fusion, Wheels, Loosely coupled, Odometry, Global positioning system
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-262453 (URN)10.1109/ACCESS.2019.2929133 (DOI)000478965200007 ()2-s2.0-85070312744 (Scopus ID)
Note

QC 20191018

Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18Bibliographically approved
Naqvi, S. I., Naqvi, A. H., Arshad, F., Riaz, M. A., Azam, M. A., Khan, M. S., . . . Tenhunen, H. (2019). An Integrated Antenna System for 4G and Millimeter-Wave 5G Future Handheld Devices. IEEE Access, 7, 116555-116566
Open this publication in new window or tab >>An Integrated Antenna System for 4G and Millimeter-Wave 5G Future Handheld Devices
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2019 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 116555-116566Article in journal (Refereed) Published
Abstract [en]

In this work, an integrated antenna system with Defected Ground Structure (DGS) is presented for Fourth Generation (4G) and millimeter (mm)-wave Fifth Generation (5G) wireless applications and handheld devices. The proposed design with overall dimensions of 110 mm x 75 mm is modeled on 0.508 mm thick Rogers RT/Duroid 5880 substrate. Radiating structure consists of antenna arrays excited by the T-shape 1 x 2 power divider/combiner. Dual bands for 4G centered at 3.8 GHz and 5.5 GHz are attained, whereas the 10-dB impedance bandwidth of 24.4 - 29.3 GHz is achieved for the 5G antenna array. In addition, a peak gain of 5.41 dBi is demonstrated across the operating bandwidth of the 4G antenna array. Similarly, for the 5G mm-wave configuration the attained peak gain is 10.29 dBi. Moreover, significant isolation is obtained between the two antenna modules ensuring efficient dual-frequency band operation using a single integrated solution. To endorse the concept, antenna prototype is fabricated and far-field measurements are procured. Simulated and measured results exhibit coherence. Also the proposed design is investigated for the beam steering capability of the mm-wave 5G antenna array using CST(R)MWS(R). The demonstrated structure offers various advantages including compactness, wide bandwidth, high gain, and planar configuration. Hence, the attained radiation characteristics prove the suitability of the proposed design for the current and future wireless handheld devices.

Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2019
Keywords
Antenna array, integrated solution, 4G, mm-wave 5G, handheld devices
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-260228 (URN)10.1109/ACCESS.2019.2936513 (DOI)000484235600004 ()
Note

QC 20190927

Available from: 2019-09-27 Created: 2019-09-27 Last updated: 2019-09-27Bibliographically approved
Shabbir, G., Ahmad, J., Raza, W., Amin, Y., Akram, A., Loo, J. & Tenhunen, H. (2019). Buffer-Aided Successive Relay Selection Scheme for Energy Harvesting IoT Networks. IEEE Access, 7, 36246-36258
Open this publication in new window or tab >>Buffer-Aided Successive Relay Selection Scheme for Energy Harvesting IoT Networks
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2019 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 36246-36258Article in journal (Refereed) Published
Abstract [en]

In this paper, we analyze the impact of buffer-aided full-duplex successive relay selection schemes with energy harvesting capability of relay nodes in amplifying and forward (AF) and decode and forward (DF) relaying environments for the Internet of Things networks. We propose to select a relay pair based on the energy harvested and signal strength at relay and destination to receive and transmit in the same time slot, respectively. Contrary to the previous relay pair selection schemes which are based on the signal strength only and cause the relay overuse problem, the proposed scheme ensures the balanced use of energy of relay nodes. The proposed relay selection scheme is implemented with the time switching (TS) and power splitting (PS)-based energy harvesting models in AF and DF relaying environments separately. Furthermore, we derive the closed-form expression of the outage probability and average throughput for both the TS and PS approaches in the DF and AF relaying modes. We compare the proposed relay selection scheme with the S-MMRS scheme and prove that the proposed scheme significantly reduces the outage probability and improves the average throughput. Furthermore, the analytical findings are reinforced with the extensive Monte Carlo simulations.

Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2019
Keywords
Buffer-aided, SWIPT, cooperative relaying, diversity gain, successive relaying
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-251232 (URN)10.1109/ACCESS.2019.2901734 (DOI)000464563300001 ()2-s2.0-85063948822 (Scopus ID)
Note

QC 20190510

Available from: 2019-05-10 Created: 2019-05-10 Last updated: 2019-05-10Bibliographically approved
Queralta, J. P., Gia, T. N., Tenhunen, H. & Westerlund, T. (2019). Collaborative Mapping with IoE-based Heterogeneous Vehicles for Enhanced Situational Awareness. In: 2019 IEEE SENSORS APPLICATIONS SYMPOSIUM (SAS): . Paper presented at 14th IEEE Sensors Applications Symposium, SAS 2019; Sophia Antipolis; France; 11 March 2019 through 13 March 2019. IEEE
Open this publication in new window or tab >>Collaborative Mapping with IoE-based Heterogeneous Vehicles for Enhanced Situational Awareness
2019 (English)In: 2019 IEEE SENSORS APPLICATIONS SYMPOSIUM (SAS), IEEE , 2019Conference paper, Published paper (Refereed)
Abstract [en]

The development of autonomous vehicles or advanced driving assistance platforms has had a great leap forward to get closer to human daily life over the last decade. Nevertheless, it is still challenging to achieve an efficient and fully autonomous vehicle or driving assistance platform due to many strict requirements and complex situations or unknown environments. One of the main remaining challenges is a robust situation awareness in autonomous vehicles when the environment is unknoen. An autonomous system with a poor situation awareness due to low quantity or quality of data may directly or indirectly cause serious consequences. For instance, a person's life might be at risk due to a delay caused by a long or incorrect path planning of an autonomous ambulance. Internet of Everything (IoE) is currently becoming a prominent technology for many applications such as automation. In this paper, we propose an IoE-based architecture consisting of a heterogeneous team of cars and drones for enhancing situational awareness in autonomous cars, especially when dealing with critical cases of natural disasters. In particular, we show how an autonomous car can plan in advance the possible paths to a given destination, and send orders to other vehicles. These, in turn, perform terrain reconnaissance for avoiding obstacles and dealing with difficult situations. Together with a map merging algorithm deployed into the team autonomous vehicles, the proposed architecture can help to save traveling distance and time significantly in case of complex scenarios.

Place, publisher, year, edition, pages
IEEE, 2019
Keywords
swarm robotics, heterogeneous swarms, cooperative mapping, Internet-of-Everything (IoE), situational awareness
National Category
Embedded Systems
Identifiers
urn:nbn:se:kth:diva-255513 (URN)10.1109/SAS.2019.8706110 (DOI)000474727000095 ()2-s2.0-85065919982 (Scopus ID)
Conference
14th IEEE Sensors Applications Symposium, SAS 2019; Sophia Antipolis; France; 11 March 2019 through 13 March 2019
Note

QC 20191016

Available from: 2019-10-16 Created: 2019-10-16 Last updated: 2019-10-16Bibliographically approved
Ebrahimi, M., Kelati, A., Nkonoki, E., Kondoro, A., Rwegasira, D., Ben Dhaou, I., . . . Tenhunen, H. (2019). Creation of CERID: Challenge, Education, Research, Innovation, and Deployment in the context of smart MicroGrid. In: Paul Cunningham ; Miriam Cunningham (Ed.), IST-Africa 2019 Conference Proceedings: . Paper presented at IST-Africa Week Conference (IST-Africa), Nairobi, KENYA, MAY 08-10, 2019.
Open this publication in new window or tab >>Creation of CERID: Challenge, Education, Research, Innovation, and Deployment in the context of smart MicroGrid
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2019 (English)In: IST-Africa 2019 Conference Proceedings / [ed] Paul Cunningham ; Miriam Cunningham, 2019Conference paper, Published paper (Refereed)
Abstract [en]

The iGrid project deals with the design and implementation of a solar-powered smart microgrid to supply electric power to small rural communities. In this paper, we discuss the roadmap of the iGrid project, which forms by merging the roadmaps of KIC (knowledge and Innovation Community) and CDE (Challenge-Driven Education). We introduce and explain a five-gear chain as Challenge, Education, Research, Innovation, and Deployment, called CERID, to reach the main goals of this project. We investigate the full chain in the iGrid project, which is established between KTH Royal Institute of Technology (Sweden) and University of Dar es Salam (Tanzania). We introduce the key stakeholders and explain how CERID goals can be accomplished in higher educations and through scientific research. Challenges are discussed, some innovative ideas are introduced and deployment solutions are recommended.

Keywords
knowledge and Innovation Community, challenge-driven educations, smart microgrid, innovation and business models.
National Category
Pedagogical Work Pedagogy Learning Computer and Information Sciences
Identifiers
urn:nbn:se:kth:diva-255686 (URN)10.23919/ISTAFRICA.2019.8764845 (DOI)000490550800030 ()2-s2.0-85069931006 (Scopus ID)978-1-905824-63-2 (ISBN)
Conference
IST-Africa Week Conference (IST-Africa), Nairobi, KENYA, MAY 08-10, 2019
Note

QC 20190819 QC 20191114

Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-11-14Bibliographically approved
Pena Queralta, J., Gia, T. N., Tenhunen, H. & Westerlund, T. (2019). Edge-AI in LoRa-based health monitoring: Fall detection system with fog computing and LSTM recurrent neural networks. In: 2019 42nd International Conference on Telecommunications and Signal Processing, TSP 2019: . Paper presented at 42nd International Conference on Telecommunications and Signal Processing, TSP 2019; Radisson Blu Beke HotelSuperior, 43. Terez krt.Budapest; Hungary; 1 July 2019 through 3 July 2019 (pp. 601-604). Institute of Electrical and Electronics Engineers (IEEE), Article ID 8768883.
Open this publication in new window or tab >>Edge-AI in LoRa-based health monitoring: Fall detection system with fog computing and LSTM recurrent neural networks
2019 (English)In: 2019 42nd International Conference on Telecommunications and Signal Processing, TSP 2019, Institute of Electrical and Electronics Engineers (IEEE), 2019, p. 601-604, article id 8768883Conference paper, Published paper (Refereed)
Abstract [en]

Remote healthcare monitoring has exponentially grown over the past decade together with the increasing penetration of Internet of Things (IoT) platforms. IoT-based health systems help to improve the quality of healthcare services through real-time data acquisition and processing. However, traditional IoT architectures have some limitations. For instance, they cannot properly function in areas with poor or unstable Internet. Low power wide area network (LPWAN) technologies, including long-range communication protocols such as LoRa, are a potential candidate to overcome the lacking network infrastructure. Nevertheless, LPWANs have limited transmission bandwidth not suitable for high data rate applications such as fall detection systems or electrocardiography monitoring. Therefore, data processing and compression are required at the edge of the network. We propose a system architecture with integrated artificial intelligence that combines Edge and Fog computing, LPWAN technology, IoT and deep learning algorithms to perform health monitoring tasks. In particular, we demonstrate the feasibility and effectiveness of this architecture via a use case of fall detection using recurrent neural networks. We have implemented a fall detection system from the sensor node and Edge gateway to cloud services and end-user applications. The system uses inertial data as input and achieves an average precision of over 90% and an average recall over 95% in fall detection.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2019
Keywords
Edge Computing, Fall Detection, Healthcare Monitoring, IoT, LoRa, LPWAN, LSTM, RNN
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-262604 (URN)10.1109/TSP.2019.8768883 (DOI)2-s2.0-85071062873 (Scopus ID)9781728118642 (ISBN)
Conference
42nd International Conference on Telecommunications and Signal Processing, TSP 2019; Radisson Blu Beke HotelSuperior, 43. Terez krt.Budapest; Hungary; 1 July 2019 through 3 July 2019
Note

QC 20191024

Available from: 2019-10-24 Created: 2019-10-24 Last updated: 2019-10-24Bibliographically approved
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