| 1. |
- Rantakokko, Jouni, et al.
(författare)
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Positioning of emergency personnel in rescue operations :
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Summary and recommendations Presently, GPS-equipped mobile phones are launched at a large scale, enabling a variety of positioning based services. Indeed, GPS is expected to be the future killer application for mobile phones and services. The concept of accurate positioning by technical means implies a large number of applications not only for the mass market, but also for rescue services, fire brigades, police forces, and military and so on. For professional and governmental safety-of-life services the current systems are far from usable and large efforts have to be concentrated on research and development. Technologies based on GPS and other satellite-based positioning systems alone are vulnerable and are expected to malfunction in indoor or challenging electromagnetic environments, or due to antagonistic measures. Satellite-based positioning is a key component in a robust communication and positioning system aimed for first responders. Satellite based positioning in combination with local radio-based positioning systems and dead-reckoning or inertial navigation systems are enablers to fulfill the users? requirements on accuracy and availability of the positioning service. Sweden is a competent player within security. Around 300 companies with some 22.000 employees have been identified within the area. Swedish industry, research institutes and universities are expected to take part in international consortiums within EU FP7, as well as being a player within DHS funded research and development within the personal positioning and navigation area. The market potential for professional and safety-of-life personal equipment for robust positioning and communication with suitable means for information presentation is significant. In the US and the EU there are some 2 million incident responders each. On a national level we count some 35.000 fire fighters, police, and military personnel in international operations. A migration of the technology to private end-consumers as implemented in consumer electronics opens up a gigantic market for wireless services within navigation, gaming, and position-awareness services. Within the project positioning of first responders in rescue operations, robust positioning has been studied. From a system perspective, technologies for positioning of personnel are key system components within a platform for positioning, information transfer for command and control, and information processing and presentation for the personnel at all levels. \? Systems for training are needed to introduce the end-user to the technology, and for training and simulation of novel strategies enabled by the technology. Stationary training systems can be implemented with state-of-the art positioning methods. Feedback from the end-user to the R&D community is instrumental in the specification and development of future means for positioning of first responders. A research infrastructure, or test-bed, for implementation and evaluation of robust positioning is an essential tool. \? The functionality of the equipment has to be robust against hostile electromagnetic environments, either due to the actual physical environment (indoor scenario, intersystem interference from nearby electronic equipment, scenario within a large steel constructions, or power plant, etc), or due to electronic warfare antagonistic actions. Research has to be performed in several areas such as channel characterization for radio positioning, quality of satellite signals subjected to interference, and integrity of sensor information due to external influences. \? Contemporary MEMS-technology provides small-size sensors with low energy consumption. The rapid development within sensor technologies enables data fusion from a plurality of sensors by digital signal processing. Fundamental issues within digital signal processing have to be studied in several fields, including methods to enhance sensor performance by incorporating behavioral modeling; fusion of digital information from a plurality of sensors; aspects of hardware implementation to fulfill requirements on size, weight and uptime, and software defined receivers for radio-based positioning, communication and mapping. In summary, future systems for positioning of first responders in rescue operations rely on the development of infra-structure aimed for end-users in a training scenario; and a platform for R&D-purposes. In parallel, fundamental issues have to be studied regarding the electromagnetic environment, as well as methodologies in digital signal processing.
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| 2. |
- Andersson, Tomas, et al.
(författare)
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IEEE standard 1057, Cramer-Rao bound and the parsimony principle
- 2006
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 55:1, s. 44-53
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Tidskriftsartikel (refereegranskat)abstract
- This paper deals with some fundamental properties of the sine-wave-fit algorithm included in IEEE Standards 1057 and 1241. Asymptotic Cramer-Rao bounds (CRBs) for three and four model parameters are derived under the Gaussian assumption. Further, the sine-wave-fitting properties of the algorithm are analyzed by the parsimony principle. A decision criterion whether to use the three- or four-parameter model is derived. It is shown that a three-parameter sine-wave fit produces a better fit than the four-parameter fit if the frequency is known to be within an interval related to the number of samples and the signal-to-noise ratio. By a numerical analysis, the theoretical results are shown to be also valid for the uniform noise model of quantization.
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| 3. |
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| 4. |
- Andersson, Tomas, et al.
(författare)
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Robustness of wave-fitting with respect to uncertain parameter values
- 2005
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Ingår i: Instrumentation and Measurement Technology Conference, 2005. IMTC 2005. Proceedings of the IEEE. ; , s. 662-665
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Konferensbidrag (refereegranskat)abstract
- This paper presents a criterion for model order selection. By usage of the parsimony principle the mean sum-squareerror is evaluated for models subject to imperfections inparameter values. In particular, model imperfections in different sinewavefitting scenarios have been analyzed. The analysis is carried out considering linear models. The obtained result is generalized to models incorporating non-linear parameters. Numerical illustrations are provided in order to gain insight of the behavior of model imperfections, as well as to numerically verify the theoretical results. The main contributions include a general result for linear signal models, as well as some novel results on sinewave-fitting.
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| 5. |
- Bjorsell, Niclas, et al.
(författare)
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Measuring Volterra kernels of analog to digital converters using a stepped three-tone scan
- 2006
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Ingår i: 2006 IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE PROCEEDINGS. - 9780780393592 ; , s. 1047-1050
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Volterra theory can be used to mathematically model nonlinear dynamic components such as analog-to-digital converter (ADC). This paper describes how frequency domain Volterra kernels of an ADC are determined from measurements. The elements of Volterra theory are given and practical issues are considered, such as methods for signal conditioning, finding the appropriate test signals scenario and suitable sampling frequency. The results show that for the used pipeline ADC, the frequency dependence is significantly stronger for second order difference products than for sum products and the linear frequency dependence was not as pronounced as that of the second order Volterra kernel.
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| 6. |
- Bjorsell, Niclas, et al.
(författare)
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Post-correction of under-sampled analog to digital converters
- 2007
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Ingår i: 2007 IEEE INSTRUMENTATION & MEASUREMENT TECHNOLOGY CONFERENCE. - : IEEE. - 9781424405886 ; , s. 58-62
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Konferensbidrag (refereegranskat)abstract
- Applications with wide bandwidth and high center frequencies force the analog to digital converter (ADC) to be active in a working range with less dynamic performance in relation to lower frequency bands. However using under-sampling techniques in combination with post-correction methods enable a combination of high sampling rate, wide bandwidth and low distortion. In this paper the employed dynamic post-correction is a combination of look-up tables and model based correction. The results are mainly based on measurements on a 12-bit 210 MSPS ADC. The improvement in total harmonic distortion and spurious free dynamic range are acceptable over a wide frequency range and it is robust to variations in amplitude.
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| 7. |
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| 8. |
- Björsell, Niclas, et al.
(författare)
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Achievable ADC Performance by Post-Correction Utilizing Dynamic Modeling of the Integral Nonlinearity
- 2008
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Ingår i: EURASIP Journal on Advances in Signal Processing. - : Springer Science and Business Media LLC. - 1110-8657 .- 1687-6180 .- 1687-6172. ; , s. 497187-1-497187-10
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Tidskriftsartikel (refereegranskat)abstract
- There is a need for a universal dynamic model of analog-to-digital converters (ADC’s) aimed for postcorrection. However, it is complicated to fully describe the properties of an ADC by a single model. An alternative is to split up the ADC model in different components, where each component has unique properties. In this paper, a model based on three components is used, and a performance analysis for each component is presented. Each component can be postcorrected individually and by the method that best suits the application. The purpose of postcorrection of an ADC is to improve the performance. Hence, for each component, expressions for the potential improvement have been developed. The measures of performance are total harmonic distortion (THD) and signal to noise and distortion (SINAD), and to some extent spurious-free dynamic range (SFDR).
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| 9. |
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| 10. |
- Björsell, Niclas, et al.
(författare)
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Dynamic behavior models of analog to digital converters aimed for post-correction in wideband applications
- 2006
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Ingår i: 18th IMEKO World Congress 2006: Metrology for a Sustainable Development. - 9781622766468 ; , s. 1344-1348, s. 5-
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Konferensbidrag (refereegranskat)abstract
- In this paper a dynamic behavior model of analog to digital converters is proposed. The model is aimed for post correction in wideband applications. The suggested post correction method is a combination of look up tables and model based correction.The model consists of three components. The first is a component represented by a Hammerstein model; that is a static nonlinearity followed by a time invariant linear filter. The second component is a nonparametric model caused by significant deviation from the characterized integral nonlinearity and the output from the Hammerstein model. The third component contains of the remaining deviation and is considered as a random model error.Results from simulations verify that the examined ADC can be described by an ordinary Hammerstein model and a static look-up table.
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