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Publikationer (10 of 15) Visa alla publikationer
Nazari, M. A., Seco-Granados, G., Johannisson, P. & Wymeersch, H. (2021). 3D Orientation Estimation with Multiple 5G mmWave Base Stations. In: ICC 2021 - IEEE International Conference on Communications: . Paper presented at ICC 2021 - IEEE International Conference on Communications.
Öppna denna publikation i ny flik eller fönster >>3D Orientation Estimation with Multiple 5G mmWave Base Stations
2021 (Engelska)Ingår i: ICC 2021 - IEEE International Conference on Communications, 2021Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

We consider the problem of estimating the 3D orientation of a user, using the downlink mmWave signals received from multiple base stations. We show that the received signals from several base stations, having known positions, can be used to estimate the unknown orientation of the user. We formulate the estimation problem as a maximum likelihood estimation in the manifold of rotation matrices. In order to provide an initial estimate to solve our non-linear non-convex optimization problem, we resort to a least squares estimation that exploits the underlying geometry. Our numerical results show that the problem of orientation estimation can be solved when the signals from at least two base stations are received. We also provide the orientation lower error bound, showing a narrow gap between the performance of the proposed estimators and the bound.

Nyckelord
Manifolds, Antenna measurements, Geometry, Base stations, Maximum likelihood estimation, Three-dimensional displays, Conferences
Nationell ämneskategori
Signalbehandling
Identifikatorer
urn:nbn:se:ri:diva-55996 (URN)10.1109/ICC42927.2021.9500778 (DOI)
Konferens
ICC 2021 - IEEE International Conference on Communications
Tillgänglig från: 2021-08-26 Skapad: 2021-08-26 Senast uppdaterad: 2021-08-26Bibliografiskt granskad
Ohlsson, F., Johannisson, P. & Rusu, C. (2021). Geometrical nonlinearities and shape effects in electromechanical models of piezoelectric bridge structures. International Journal of Energy and Environmental Engineering, 12, 725
Öppna denna publikation i ny flik eller fönster >>Geometrical nonlinearities and shape effects in electromechanical models of piezoelectric bridge structures
2021 (Engelska)Ingår i: International Journal of Energy and Environmental Engineering, ISSN 2008-9163, E-ISSN 2251-6832, Vol. 12, s. 725-Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We consider nonlinear shape effects appearing in the lumped electromechanical model of a bimorph piezoelectric bridge structure due to the interaction between the electromechanical constitutive model and the geometry of the structure. At finite proof-mass displacement and electrode voltage, the shape of the beams is no longer given by Euler-Bernoulli theory which implies that shape effects enter in both the electrical and mechanical domains and in the coupling between them. Accounting for such effects is important for the accurate modelling of, e.g., piezoelectrical energy harvesters and actuators in the regime of large deflections and voltages. We present a general method, based on a variational approach minimizing the Gibbs enthalpy of the system, for computing corrections to the nominal shape function and the associated corrections to the lumped model. The lowest order correction is derived explicitly and is shown to produce significant improvements in model accuracy, both in terms of the Gibbs enthalpy and the shape function itself, over a large range of displacements and voltages. Furthermore, we validate the theoretical model using large deflection finite element simulations of the bridge structure and conclude that the lowest order correction substantially improve the model, obtaining a level of accuracy expected to be sufficient for most applications. Finally, we derive the equations of motion for the lowest order corrected model and show how the coupling between the electromechanical properties and the geometry of the bridge structure introduces nonlinear interaction terms. © 2021, The Author(s).

Ort, förlag, år, upplaga, sidor
Springer Science and Business Media Deutschland GmbH, 2021
Nyckelord
Computation theory, Enthalpy, Equations of motion, Nonlinear equations, Piezoelectricity, Electromechanical modeling, Electromechanical models, Electromechanical property, Euler-Bernoulli theory, Finite element simulations, Geometrical non-linearity, Nonlinear interactions, Variational approaches, Geometry
Nationell ämneskategori
Beräkningsmatematik
Identifikatorer
urn:nbn:se:ri:diva-53479 (URN)10.1007/s40095-021-00395-z (DOI)2-s2.0-85106508334 (Scopus ID)
Anmärkning

Funding details: Horizon 2020 Framework Programme, H2020, 644378; Funding text 1: This work has received funding from The European Union’s Horizon 2020 research and innovation programme under grant agreement No 644378, Smart-Memphis project, and from internal funding of RISE Research Institutes of Sweden.

Tillgänglig från: 2021-06-17 Skapad: 2021-06-17 Senast uppdaterad: 2023-05-16Bibliografiskt granskad
Lindell, H. & Johannisson, P. (2021). Method for defining and quantifying shock vibration from hand-held machines. In: Proceedings of the 8th American Conference on Human Vibration: . Paper presented at 8th American Conference on Human Vibration. 2June 23-25, 2021;​ Online due to COVID-19.
Öppna denna publikation i ny flik eller fönster >>Method for defining and quantifying shock vibration from hand-held machines
2021 (Engelska)Ingår i: Proceedings of the 8th American Conference on Human Vibration, 2021Konferensbidrag, Publicerat paper (Refereegranskat)
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-60328 (URN)
Konferens
8th American Conference on Human Vibration. 2June 23-25, 2021;​ Online due to COVID-19
Tillgänglig från: 2022-10-12 Skapad: 2022-10-12 Senast uppdaterad: 2023-05-17Bibliografiskt granskad
Geréb, G., Johannisson, P. & Landén, L. (2021). Sensor Platform for Low-Power Underwater Monitoring using Hydroacoustic Communication. In: 2021 Smart Systems Integration (SSI): . Paper presented at 2021 Smart Systems Integration (SSI). 27-29 April 2021.Grenoble, France..
Öppna denna publikation i ny flik eller fönster >>Sensor Platform for Low-Power Underwater Monitoring using Hydroacoustic Communication
2021 (Engelska)Ingår i: 2021 Smart Systems Integration (SSI), 2021Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

The development of a compact, battery-powered sensor platform intended for underwater applications and using hydroacoustic communication is reported. The design and manufacturing of the device is described with emphasis on the method used to monitor and reduce the current consumption. The devices have been encapsulated in epoxy and evaluated under field conditions, which showed that the system is usable in its current form. In addition to hardware improvements, e.g., in order to increase battery lifetime, the next generation of the system will implement forward error correction and improved receiver signal processing to reduce the impact of signal reflections.

Nyckelord
Wireless communication, Wireless sensor networks, System integration, Signal processing, Reflection, Batteries, Manufacturing, Sensor systems, underwater communication, acoustic devices, underwater acoustics
Nationell ämneskategori
Annan elektroteknik och elektronik
Identifikatorer
urn:nbn:se:ri:diva-55412 (URN)10.1109/SSI52265.2021.9466953 (DOI)
Konferens
2021 Smart Systems Integration (SSI). 27-29 April 2021.Grenoble, France.
Tillgänglig från: 2021-07-08 Skapad: 2021-07-08 Senast uppdaterad: 2021-07-08Bibliografiskt granskad
Fougstedt, C., Sheikh, A., Johannisson, P. & Larsson-Edefors, P. (2018). Filter Implementation for Power-Efficient Chromatic Dispersion Compensation. IEEE Photonics Journal, 10(4), Article ID 7202919.
Öppna denna publikation i ny flik eller fönster >>Filter Implementation for Power-Efficient Chromatic Dispersion Compensation
2018 (Engelska)Ingår i: IEEE Photonics Journal, E-ISSN 1943-0655, Vol. 10, nr 4, artikel-id 7202919Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Chromatic dispersion (CD) compensation in coherent fiber-optic systems represents a very significant DSP block in terms of power dissipation. Since spectrally efficient coherent systems are expected to find a wider deployment in systems shorter than long haul, it becomes relevant to investigate filter implementation aspects of CD compensation in the context of systems with low-to-moderate amounts of accumulated dispersion. The investigation we perform in this paper has an emphasis on implementation aspects such as power dissipation and area usage, it deals with both time-domain and frequency-domain CD compensations, and it considers both A/D-conversion quantization and fixed-point filter design aspects. To enable an accurate analysis on power dissipation and chip area, the evaluated filters are implemented in a 28-nm fully depleted silicon-on-insulator (FD-SOI) process technology. We show that an optimization of the filter response that takes pulse shaping into account can significantly reduce power dissipation and area usage of time-domain implementations, making them a viable alternative to frequency-domain implementations.

Nyckelord
digital signal processing chips, frequency-domain analysis, optical fibre communication, silicon-on-insulator, time-domain analysis, DSP block, frequency-domain implementations, time-domain implementations, filter response, fixed-point filter design aspects, frequency-domain CD compensations, low-to-moderate amounts, CD compensation, spectrally efficient coherent systems, power dissipation, coherent fiber-optic systems, power-efficient chromatic dispersion compensation, filter implementation, Finite impulse response filters, Optimization, Design methodology, Chromatic dispersion, Throughput, Optical fiber communication, digital signal processing, application specific integrated circuits
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-34351 (URN)10.1109/JPHOT.2018.2846799 (DOI)2-s2.0-85048524365 (Scopus ID)
Tillgänglig från: 2018-08-06 Skapad: 2018-08-06 Senast uppdaterad: 2022-09-28Bibliografiskt granskad
Johannisson, P., Ohlsson, F. & Rusu, C. (2018). Impact-driven up-conversion in piezoelectric MEMS energy harvesters with pulsed excitation. In: Journal of Physics: Conference Series. Paper presented at 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2017, 14 November 2017 through 17 November 2017. (1), Article ID 012106.
Öppna denna publikation i ny flik eller fönster >>Impact-driven up-conversion in piezoelectric MEMS energy harvesters with pulsed excitation
2018 (Engelska)Ingår i: Journal of Physics: Conference Series, 2018, nr 1, artikel-id 012106Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

The potential of impact-driven frequency up-conversion in a MEMS EH is evaluated using numerical simulations. The investigated design is compared to a conventional cantilever EH in terms of output power and loss rate. The upshifting can lead to significantly increased output power at a similar loss rate but as the time scale for the loss is long, the benefit is limited. This also requires an effective upshifting process. The design of the impact introduces a length scale that must be selected with excitation, gravity, and pre-stress taken into account. This makes this type of EH application-dependent as a non-optimal choice may result in low output power.

Nyckelord
Frequency converters, Nanotechnology, Energy Harvester, Frequency up conversion, Length scale, Optimal choice, Output power, Piezoelectric MEMS, Pulsed excitation, Up conversion, Energy conversion
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-34960 (URN)10.1088/1742-6596/1052/1/012106 (DOI)2-s2.0-85051348585 (Scopus ID)
Konferens
17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2017, 14 November 2017 through 17 November 2017
Tillgänglig från: 2018-09-05 Skapad: 2018-09-05 Senast uppdaterad: 2023-05-16Bibliografiskt granskad
Irukulapati, M., Secondini, M., Agrell, E., Johannisson, P. & Wymeersch, H. (2018). Improved Lower Bounds on Mutual Information Accounting for Nonlinear Signal--Noise Interaction. Journal of Lightwave Technology, 36(22), 5152-5159
Öppna denna publikation i ny flik eller fönster >>Improved Lower Bounds on Mutual Information Accounting for Nonlinear Signal--Noise Interaction
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2018 (Engelska)Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 36, nr 22, s. 5152-5159Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In fiber-optic communications, evaluation of mutual information (MI) is still an open issue due to the unavailability of an exact and mathematically tractable channel model. Traditionally, lower bounds on MI are computed by approximating the (original) channel with an auxiliary forward channel. In this paper, lower bounds are computed using an auxiliary backward channel, which has not been previously considered in the context of fiber-optic communications. Distributions obtained through two variations of the stochastic digital backpropagation (SDBP) algorithm are used as auxiliary backward channels and these bounds are compared with bounds obtained through the conventional digital backpropagation (DBP). Through simulations, higher information rates were achieved with SDBP, which can be explained by the ability of SDBP to account for nonlinear signal--noise interactions

Nyckelord
Achievable information rate, auxiliary channel, fiber-optical communications, mismatched decoding, nonlinear compensation, stochastic digital backpropagation, Backpropagation algorithms, Fiber optics, Nonlinear optics, Signal noise measurement, Stochastic systems, Digital backpropagation, Fiber optical communications, Non-linear compensations, Optical fiber communication
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-35200 (URN)10.1109/JLT.2018.2869109 (DOI)2-s2.0-85052855904 (Scopus ID)
Tillgänglig från: 2018-10-10 Skapad: 2018-10-10 Senast uppdaterad: 2019-06-27Bibliografiskt granskad
Ohlsson, F., Johannisson, P. & Rusu, C. (2018). Shape effects in doubly clamped bridge structures at large deflections. In: Journal of Physics: Conference Series. Paper presented at 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2017, 14 November 2017 through 17 November 2017. , 1052(1)
Öppna denna publikation i ny flik eller fönster >>Shape effects in doubly clamped bridge structures at large deflections
2018 (Engelska)Ingår i: Journal of Physics: Conference Series, 2018, Vol. 1052, nr 1Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

The shape of a doubly clamped bridge structure depends on its deflection. At large deflections, where the system exhibits nonlinear behaviour, the shape effect becomes significant. We present a general method, based on variational analysis, for computing corrections to the nominal linear regime shape function. The method is used to compute the first non-trivial correction and quantify the corresponding improvement in the large deflection regime. The model obtained is also validated using FEM simulations.

Nyckelord
Energy conversion, Nanotechnology, Bridge structures, FEM simulations, General method, Large deflection, Linear regime, Nonlinear behaviours, Shape functions, Variational analysis, Deflection (structures)
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-34959 (URN)10.1088/1742-6596/1052/1/012109 (DOI)2-s2.0-85051341507 (Scopus ID)
Konferens
17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2017, 14 November 2017 through 17 November 2017
Tillgänglig från: 2018-08-27 Skapad: 2018-08-27 Senast uppdaterad: 2023-05-16Bibliografiskt granskad
Larsson, S., Johannisson, P., Kolev, D., Ohlsson, F., Nik, S., Liljeholm, J., . . . Rusu, C. (2018). Simple method for quality factor estimation in resonating MEMS structures. In: Proceedings of the 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, 2017: . Paper presented at 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2017, 14 November 2017 through 17 November 2017. (1)
Öppna denna publikation i ny flik eller fönster >>Simple method for quality factor estimation in resonating MEMS structures
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2018 (Engelska)Ingår i: Proceedings of the 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, 2017, 2018, nr 1Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

The quality factor of a packaged MEMS resonating structure depends on both the packaging pressure and the structure's proximity to the walls. This type of mechanical constraints, which causes energy dissipation from the structure to the surrounding air, are applicable for oscillating energy harvesters and should be considered in the design process. However, the modelling of energy losses or the measurements of their direct influence inside a packaged chip is not trivial. In this paper, a simple experimental method to quantify the energy loss in an oscillating MEMS structures due to the surrounding air is described together with preliminary results. The main advantage of the method is the ability to characterize the damping contributions under different vacuum and packaging conditions without requiring any packaging of the harvester chip or fabrication of multiple devices with different cavity depths. © Published under licence by IOP Publishing Ltd.

Nyckelord
Energy conversion, Energy dissipation, Nanotechnology, Damping contribution, Energy Harvester, Experimental methods, Mechanical constraints, Multiple devices, Quality factor estimation, Quality factors, Resonating structures, Chip scale packages
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-34961 (URN)10.1088/1742-6596/1052/1/012100 (DOI)2-s2.0-85051331110 (Scopus ID)
Konferens
17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2017, 14 November 2017 through 17 November 2017
Tillgänglig från: 2018-08-28 Skapad: 2018-08-28 Senast uppdaterad: 2023-05-16Bibliografiskt granskad
Czegledi, C. B., Karlsson, M., Johannisson, P. & Agrell, E. (2017). Temporal stochastic channel model for absolute polarization state and polarization-mode dispersion. In: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings: . Paper presented at 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017, 19 March 2017 through 23 March 2017. Los Angeles, USA.
Öppna denna publikation i ny flik eller fönster >>Temporal stochastic channel model for absolute polarization state and polarization-mode dispersion
2017 (Engelska)Ingår i: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings, 2017Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

We propose and validate a discrete-time channel model for the temporal drift of the absolute polarization state and polarization-mode dispersion for coherent fiber optic systems. The model can be used in simulations to test and develop DSP for coherent receivers.

Nyckelord
Optical fiber communication, Optical fibers, Polarization, Stochastic systems, Coherent receivers, Discrete-time channels, Fiber optic system, Polarization state, Stochastic channel model, Temporal drifts, Stochastic models
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-30910 (URN)10.1364/OFC.2017.Th3F.2 (DOI)2-s2.0-85025807946 (Scopus ID)9781943580231 (ISBN)
Konferens
2017 Optical Fiber Communications Conference and Exhibition, OFC 2017, 19 March 2017 through 23 March 2017. Los Angeles, USA
Tillgänglig från: 2017-09-07 Skapad: 2017-09-07 Senast uppdaterad: 2019-06-27Bibliografiskt granskad
Organisationer
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-1793-4451

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