| 1. |
- Abbas, Taimoor, et al.
(författare)
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A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations
- 2015
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Ingår i: International Journal of Antennas and Propagation. - : Hindawi Publishing Corporation. - 1687-5869 .- 1687-5877.
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Tidskriftsartikel (refereegranskat)abstract
- The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicular ad hoc networks (VANETs). Extensive research efforts have been made to develop V2V channel models to be implemented in advanced VANET system simulators for performance evaluation. The impact of shadowing caused by other vehicles has, however, largely been neglected in most of the models, as well as in the system simulations. In this paper we present a shadow fading model targeting system simulations based on real measurements performed in urban and highway scenarios. The measurement data is separated into three categories, line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non-line-of-sight due to buildings, with the help of video information recorded during the measurements. It is observed that vehicles obstructing the LOS induce an additional average attenuation of about 10 dB in the received signal power. An approach to incorporate the LOS/OLOS model into existing VANET simulators is also provided. Finally, system level VANET simulation results are presented, showing the difference between the LOS/OLOS model and a channel model based on Nakagami-m fading.
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| 2. |
- Ge, Yu, 1995, et al.
(författare)
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Experimental Validation of Single Base Station 5G mm Wave Positioning: Initial Findings
- 2022
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Ingår i: 2022 25th International Conference on Information Fusion, FUSION 2022. - Piscataway : IEEE.
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Konferensbidrag (refereegranskat)abstract
- 5G cellular networks can utilize millimeter wave signals, and support large bandwidths and large antenna arrays, which provide more geometric-based signals and higher delay and angle resolutions. These merits bring new opportunities in positioning the user with limited infrastructure through the use of combined angle and delay information. However, there are many practical challenges to overcome, in order to have a functioning single base station 5G mmWave positioning system. In this paper, we describe a deployed single base station mmWave positioning system, and provide an example of the measurement data. Furthermore, we perform measurement validation on a limited measurement data set by performing base station localization. Additional evaluations performed on simulation model data provide guidelines on the required size of the data set and receiver antenna configuration, which will be implemented in upcoming measurements.
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| 3. |
- Sjöberg, Katrin, et al.
(författare)
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Measuring and using the RSSI of IEEE 802.11p
- 2010
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Ingår i: 17th World Congress on Intelligent Transport Systems, ITS 2010, Busan, South Korea, 25-29 October 2010.
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Konferensbidrag (refereegranskat)abstract
- The scalability of intelligent transport systems (ITS) applications is difficult to test in a field operational test (FOT) due to the high number of ITS equipped vehicles required. Therefore, computer simulations for evaluating different wireless communication technologies for ITS different applications can serve as a complement. In this paper we present results from lab measurements conducted on the CVIS hardware platform equipped with the upcoming standard IEEE 802.11p. We have measured the packet error rate versus the signal-to-noise ratio (SNR) for different packet lengths. This lab measurement is the first step towards an outdoor measurement campaign which also considers interference. The outdoor measurements will then be fed into a computer simulator together with a realistic channel model for evaluating the scalability of VANETs in a highway scenario.
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| 4. |
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| 5. |
- Malmberg, Donald
(författare)
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Innovative Contact Free Sensors for Metallurgical Process Control
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The steel- and metal industry has an extensive production processing comprising many different process steps of solid, gaseous and liquid nature. Thus it is obvious that a number of different measurement technologies must be used to collect and evaluate key physical parameters which are necessary to control the production processes. In this respect, the software to monitor the processes have, during the past decade, undergone extensive improvement whilst the sensors reading off the instantaneous process status have not and are still afflicted with severe drawbacks.This situation, in combination with increased demands on energy savings and rules regarding reduction of green house gas emission (the Kyoto protocol), has created incentives for the development and implementation of new technologies to monitor and control production processes in the steel and metal industry.The objectives in this thesis are to develop and evaluate sensor technology that can be used for in-situ on line analysis of metallurgical processes.The work is divided into:- To test and evaluate microwave technology for on line slag analysis.- To design, develop and evaluate microwave sensors for off gas analysis.- To evaluate laser sensors for simultaneous analysis of the process environment in metallurgical processes with emphasis on measuring the oxygen concentration and temperature in a steel reheating furnaceDuring the work on slag a broad band antenna was used for the microwave investigations on solid and liquid slag. The results show that it is possible to evaluate a refractive index for both solid and liquid slag. The results also show that there is a weak correlation between the refractive index for liquid slag and slag basicity.Trials on off gases from a pilot process as well as a full scale metallurgical production processes have been performed with microwave technology. The instrument used for the microwave trials has been developed from individual components. The results show that it is possible to use the technology for process analysis however the data collected regarding individual spectral lines still remain to be correlated to known molecular frequencies.Laser technology for gas analysis is a known technology in many different industrial applications. However, using the technology in steel and metal production processes requires that the technology must be adapted to the environment specific to those processes. Trials on a pilot process has been performed to find a suitable set of O2 absorption line parameters to be used during the forthcoming trials of full scale production processes. The outcome of these trials clearly show that the TDLAS technology can be used successfully on reheating furnaces but have a limited application potential on the LD converter process as well as the EAF.The benefit of the presented work will on production scale contribute to a lowered emission of green house gases, lowered energy consumption and an improved production yield.
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| 6. |
- Marinho, Marco A. M., 1986-, et al.
(författare)
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Non-Line-of-Sight Based Radio Localization With Dual-Polarization Antenna Arrays
- 2020
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Ingår i: WSA 2020. - Berlin : VDE Verlag GmbH. - 9783800752003
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Konferensbidrag (refereegranskat)abstract
- This work presents an approach for radio-based localization in non-line-of-sight (NLOS) environments by leveraging a dual-polarization antenna array. By estimating the polarization of the received signal, it is possible to estimate the angle of reflection of a NLOS signal. An estimate of the position of the transmitter concerning the receiver can be obtained based on a joint estimation of the reflection angle of several NLOS signals together with their respective directions of arrival (DOAs) and time differences of arrival (TDOAs). A set of numerical simulations is used to assess the performance of the proposed method. © VDE VERLAG GMBH. Berlin. Offenbach
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| 7. |
- Marinho, Marco A. M., 1986-, et al.
(författare)
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Performance Assessment for Distributed Broadband Radio Localization
- 2018
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Ingår i: 2018 52nd Asilomar Conference on Signals, Systems, and Computers. - Washington, DC : IEEE. - 9781538692189 - 9781538692165 - 9781538692172 - 9781538692196 ; , s. 20-23
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Konferensbidrag (refereegranskat)abstract
- Various emerging technologies, such as autonomous vehicles and fully autonomous flying, require precision positioning. This work presents a localization and tracking method based on joint direction of arrival (DOA), time delay, and range estimation using the SAGE algorithm. The proposed method does not rely on external sources of information such as global navigation satellite systems (GNSS). The method is opportunistic and does not require any location-based data exchange. A set of numerical simulations is presented to assess the performance of the proposed method.
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| 8. |
- Marques Marinho, Marco Antonio, 1986-, et al.
(författare)
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Spherical Wave Array Based Positioning for Vehicular Scenarios
- 2020
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Ingår i: IEEE Access. - Piscataway, N.J. : IEEE. - 2169-3536. ; 8, s. 110073-110081
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Tidskriftsartikel (refereegranskat)abstract
- Smart vehicles are emerging as a possible solution for multiple concerns in road traffic, such as mobility and safety. This work presents radio localization methods based on simultaneous direction of arrival (DOA), time-delay, and range estimation using the SAGE algorithm. The proposed methods do not rely on external sources of information, such as global navigation satellite systems (GNSS). The proposed methods take advantage of signals of opportunity and do not require the transmission of location-specific signals; therefore, they do not increase the network load. A set of simulations using synthetic and measured data is provided to validate the proposed methods, and the results show that it is possible to achieve accuracy down to decimeter and centimeter-level. © 2013 IEEE.
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| 9. |
- Nelson, Christian, et al.
(författare)
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Geometry Based Channel Models with Cross- and Autocorrelation for Vehicular Network Simulations
- 2018
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Ingår i: 2018 IEEE 87th Vehicular Technology Conference (VTC Spring). - Piscataway, NJ : IEEE. - 2577-2465. - 9781538663554 - 9781538663547 - 9781538663561
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Konferensbidrag (refereegranskat)abstract
- Realistic network simulations are necessary to assess the performance of any communication system. In this paper, we describe an implementation of a channel model for vehicle-to-vehicle (V2V) communication in the OMNeT++/Plexe simulation environment. The model is based on previous extensive measurements in a V2V multilink highway scenario and cover line-of-sight (LOS) as well as obstructed LOS (OLOS) scenarios, which occurs when one or more vehicles obstruct the LOS component. The implementation captures both the temporal autocorrelation and the joint multilink cross-correlation processes to achieve a realistic behavior. Preliminary results show that the implementation now generates stochastic large-scale fading with an autocorrelation function that agrees well with measured data. A representation of the cross-correlation process is now implemented through proper channel model selection since the geometry and location of objects are known in Plexe. We also show the impact of the suggested V2V physical layer (PHY) on the performance evaluation results observed at the facilities layer. As a metric, we use the data age, which is a measure how old the information about a vehicle is. When considering the autocorrelation in simulations, the experienced data-age increases. Examples show an increase of the 10% percentile data-age from 0.1s to 1.5s, which may affect the application performance significantly in critical situations. © 2018 IEEE.
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| 10. |
- Savas, Süleyman, 1986-, et al.
(författare)
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A framework to generate domain-specific manycore architectures from dataflow programs
- 2020
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Ingår i: Microprocessors and microsystems. - Amsterdam : Elsevier. - 0141-9331 .- 1872-9436. ; 72
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Tidskriftsartikel (refereegranskat)abstract
- In the last 15 years we have seen, as a response to power and thermal limits for current chip technologies, an explosion in the use of multiple and even many computer cores on a single chip. But now, to further improve performance and energy efficiency, when there are potentially hundreds of computing cores on a chip, we see a need for a specialization of individual cores and the development of heterogeneous manycore computer architectures.However, developing such heterogeneous architectures is a significant challenge. Therefore, we propose a design method to generate domain specific manycore architectures based on RISC-V instruction set architecture and automate the main steps of this method with software tools. The design method allows generation of manycore architectures with different configurations including core augmentation through instruction extensions and custom accelerators. The method starts from developing applications in a high-level dataflow language and ends by generating synthesizable Verilog code and cycle accurate emulator for the generated architecture.We evaluate the design method and the software tools by generating several architectures specialized for two different applications and measure their performance and hardware resource usages. Our results show that the design method can be used to generate specialized manycore architectures targeting applications from different domains. The specialized architectures show at least 3 to 4 times better performance than the general purpose counterparts. In certain cases, replacing general purpose components with specialized components saves hardware resources. Automating the method increases the speed of architecture development and facilitates the design space exploration of manycore architectures.
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