ELEDIA@UniTN

ELEDIA Turns 20!
ELEDIA Turns 20! It was back in October-November 2000 that the ELEDIA brand began to circulate in an official form…
ELEDIA Artificial Intelligence Research Blog is online!
The ELEDIA Artificial Intelligence Research Blog (E-AIR Blog) has been launched! Check out our latest advancements on Artificial Intelligence as applied…
Dr. R. J. MAILLOUX awarded "Bruno Kessler" Honorary Professor
The ELEDIA Research Center is pleased to announce that Dr. Robert J. MAILLOUX will receive the title of Honorary Professor…
 
 
The recontruction of the dielectric properties of unknow targets within an inaccessible investigation domain starting from non-invasive measurements of the electromagnetic field, it is of fundamental importance in various applications such as biomedical imaging, geophysical prospecting and non-destructive testing. Unfortunatly, since the aquired data of the electromagnetic field are usually limited and affected by errors and noise and the inverse problem results to be non-linear and ill-posed, it is quite difficult to achieve reliable and accurate solutions without a smart use of the information on the problem at hand. In this framework, Compressive Sensing approaches which exploit the a-priori knowledge on the unknowns' sparseness are currently object of study for the solution of inverse scattering problem thanks to their reliability, effectiveness and robustness to the noise.
   
Biomedical Imaging, geophysical prospecting, non-destructive testing


 

 
According to the CS theory, an unknown/signal phenomena can be enforced to be compressible with respect to suitable expansion bases (i.e., the corresponding vectors of expansion coefficients have few nonzero entries): exploiting the sparseness of the scatterer objects inside the investigation domain, members of ELEDIA Research Center have developed several techniques based on the CS theory aimed at reconstruct the phisical features of the objects under investigation, starting from the measurement of the elctromagnetic scattered fields. In particular, a Bayesian Compressive Sampling (BCS) approach has been considered: a "probabilistic" regularization has been used to reformulate the original inverse problem as a BCS one, and both the Contrast Source formulation and the Born & Rytov approximations has been investigated, exploiting either tranverse magnetic (TM) or transverse electric (TE) wave polarizations, for the reconstrution of the dielectric and conductivity properties of the unknown objects.
Cross-Shaped Object - BCS Reconstructed Profile
L-Shaped Object - BCS Reconstructed Profile

Keywords: Biomedical Imaging, Inverse Scattering, Compressive Sensing, Bayesian Compressive Sensing


See Also
  • G. Oliveri, P. Rocca, and A. Massa, "A Bayesian-compressive-sampling-based inversion for imaging sparse scatterers," IEEE Trans. Geosci. Remote Sens., vol. 49, no. 10, pp. 3993-4006, Oct. 2011.
    doi:10.1109/TGRS.2011.2128329
  • L. Poli, G. Oliveri, and A. Massa, "Microwave imaging within the first-order Born approximation by means of the contrast-field Bayesian compressive sensing," IEEE Trans. Antennas Propag., vol. 60, no. 6, pp. 2865-2879, Jun. 2012.
    doi:10.1109/TAP.2012.2194676
  • G. Oliveri, L. Poli, P. Rocca, and A. Massa, "Bayesian compressive optical imaging within the Rytov approximation," Optics Letters, vol. 37, no. 10, pp. 1760-1762, 2012.
    doi:10.1364/OL.37.001760
  • S. Ji, Y. Xue, and L. Carin, "Bayesian compressive sensing," IEEE Trans. Signal Process., vol. 56, no. 6, pp. 2346-2356, 2008. 10.1109/TSP.2007.914345L. Poli, G. Oliveri, F. Viani, and A. Massa, "MT-BCS-based microwave imaging approach through minimum-norm current expansion," IEEE Trans. Antennas Propag., vol. 61, no. 9, pp. 4722-4732, Sept. 2013.
    doi:10.1109/TAP.2013.2265254
  • L. Poli, G. Oliveri, P. Rocca, and A. Massa, "Bayesian compressive sensing approaches for the reconstruction of two-dimensional sparse scatterers under TE illumination," IEEE Trans. Geosci. Remote Sensing, vol. 51, no. 5, pp. 2920-2936, May. 2013.
    doi:10.1109/TGRS.2012.2218613
  • L. Poli, G. Oliveri, and A. Massa, "Imaging sparse metallic cylinders through a Local Shape Function Bayesian Compressive Sensing approach," Journal of Optical Society of America A, vol. 30, no. 6, pp. 1261-1272, 2013.
    doi:10.1364/JOSAA.30.001261
  • F. Viani, L. Poli, G. Oliveri, F. Robol, and A. Massa, "Sparse scatterers imaging through approximated multitask compressive sensing strategies," Microwave Opt. Technol. Lett., vol. 55, no. 7, pp. 1553-1558, Jul. 2013.
    doi:10.1002/mop.27612
   

 

 
 
The efficient exploitation of the available mobile communication channels is a very important issue, which is motivated by the ever-growing number of users that can interact at the same time with a base station. For this reason, it is necessary to develop methods which are able to improve the performances of transmitting/receiving systems in mobile communication networks. Toward this end, the use of antenna array can provide higher system capacities by providing narrow beam toward the user of interest, while nulling other users not of interest. Another advantage of Antenna Arrays is that the multipath fading (i.e. the reception of multiple copies of the same signal due to multiple reflections) can be eliminated by nulling multipath signals. In order to implement such kinds of strategies, the first step is the estimation of the direction of arrival (DoA) of the desired and undesired signals impinging on the antenna array. The information gathered in this step are fundamental to drive the successive beamforming process.
   
Smart Antennas, Radio Astronomy, Search and Rescue Services, Location Systems, Homing systems, Warning systems


 

Smart Atennas


Target Tracking Radar System
 

The reasearch activities of the Members of the ELEDIA Research Center are aimed at the development of innovative methdologies for the solution of the DoA estimation problem. In particular the under-development strategies are based on the exploitation of Bayesian Compressive Sensing (BCS) for the estimation of the received spatial signal spectrum. The main advantages of this method are:

  1. It enables the achievement of accurate estimations even with a limited number of snapshots, making this techniques suitable for real-time applications.
  2. The performances of the method are not affected by the correlation among the impinging signals, making this method approprate for multipath scenarios.
  3. Statistical assumptions on the impinging signal are not necessary.
  4. The knowledge of the number of signals is not needed.

 

Large Number Of Signals

 

Closely Spaced Sources

Keywords: Direction-of-Arrival estimation, Bayesian Compressive Sampling (BCS), Smart Antennas.


See Also
  • G. Oliveri, P. Rocca, and A. Massa, "A Bayesian-Compressive-Sampling-Based Inversion for Imaging Sparse Scatterers," IEEE Transactions on Geoscience and Remote Sensing, vol. 49, no. 10, pp. 3993-4006, Oct. 2011
    doi:10.1109/TGRS.2011.2128329
  • M. Carlin, P. Rocca, G. Oliveri, F. Viani, and A. Massa, "Directions-of-Arrival Estimation through Bayesian Compressive Sensing strategies," IEEE Transactions on Antennas and Propagation, vol. 61, no. 7, pp. 3828-3838, Jul. 2013.doi:10.1109/TAP.2013.2256093
  • M. Carlin, P. Rocca, G. Oliveri, and A. Massa, "Bayesian Compressive Sensing as applied to Direction-of-Arrival estimation in planar arrays," Journal of Electrical and Computer Engineering, vol. 2013, pp. 1-13, 2013.
    doi:10.1155/2013/245867
  • M. Carlin, P. Rocca, "A Bayesian compressive sensing strategy for direction-of-arrival estimation," 6th European Conference on Antennas and Propagation (EuCAP 2012), Prague, Czech Republic, pp. 1508-1509, 26-30 Mar. 2012.
    doi:10.1109/EuCAP.2012.6206667
  • M. Carlin, P. Rocca, G. Oliveri, and A. Massa, "Multi-task Bayesian compressive sensing for direction-of-arrival estimation," IEEE International Conference on Wireless Information Technology and Systems (ICWITS), Maui, Hawaii, USA, pp. 1-4, 11-16 Nov. 2012.
    doi:10.1109/ICWITS.2012.6417819
   

 

 


 
 
The design of microwave components for Electromagnetic Compatibility purposes (e.g., filters, splitters, combiners, circulators, etc.) is a challenging task because of the requirements that they must satisfy to fit industrial requirements. In such a context, EMI (ElectroMagnetic Interference) filters aimed at attenuating the signals interfering on the input/output connection ports of a device are among the most employed devices from the practical viewpoint. Unfortunately, despite the importance of such components at the industrial level, general purpose design algorithms able to effectively with multiple concurring objectives and constraints are still not available. Accordingly, efficient and effective methodologies enabling the fast design of arbitrary EMI filters are of great importance for advanced manufacturing and processing purposes in the Electromagnetic Compatibility industry.
   
Industrial Electromagnetic Compatibility

 



Example Of EMI Filter


ELEDIA Design Tool
 

Members of the ELEDIA Research Center have worked at the development of unsupervised design approaches for the synthesis of filters able to suppress the unwanted radio-disturbances as well as to satisfy the other design requirements, including

  1. insertion loss due to common mode and differential mode currents and voltages;
  2. input and output impedance;
  3. maximal leakage and self-power-consumption current.

The synthesis procedures exploit Evolutionary Algorithms in combination with circuit simulators and equivalent models of the used components. Particular importance is given to the ad-hoc design for specific problems, to the accurate performances prediction of the synthesized device, to the direct realization of the device starting from the results obtained during the synthesis procedure.

   

Keywords: Electromagnetic Compatibility


See Also
  • R. Azaro, L. Ioriatti, M. Martinelli, and A. Massa, "Automatic design and optimisation of EMI filter using commercially-available components," Electron. Lett. , vol. 43, no. 6, pp.15-16, March 2007
    doi: 10.1049/el:20073923
   

 

 
 
Shared aperture antennas are of great interest in modern wireless systems for communications, detection, location and remote sensing because of the need to realise multiple functions in a limited space. In this framework, aperture arrays of intermixed elements provide interesting performances in terms of hardware complexity, aperture efficiency and flexibility. However, each array of an interleaved arrangement usually shows a lower gain and a higher peak sidelobe level (PSL) than the corresponding non-interlaced design. Accordingly, numerically efficient design approaches able to control the sidelobe level of shared aperture antenna arrays are of great interest from the applicative viewpoint.
   
Satellite systems for wireless communications, biomedical instruments, antenna arrays for environmental monitoring and observation, reconfigurable polarization systems.

 



 

Interleaved Array Geometry For Pulse-Echo Application
 

Members of the ELEDIA Research Center have introduced analytical design approaches for the synthesis of fully-interleaved arrays (two-function of multi-function) with controlled sidelobes. Such methodologies are based on the exploitation of Almost Difference Sets (ADS). The enabling features of these binary sequences include

  1. their design efficiency, which owes to their analytical nature and their availability for arrangements comprising several thousands elements;
  2. their complementarity property, which means that the ADS predictable autocorrelation features (and relative sidelobe control properties) hold true for all synthesized beams;

The research activities carried out in this area have been focused on the introduction, study, and development of ADS-based design techniques for linear and planar interleaved arrays for several different applications (including biomedical imaging, pulse-echo arrays, and reconfigurable polarization systems).

   

Synthesized Pulse-Echo Beam Patterns With Different Steering Angles

Keywords: Thinned arrays, Almost Difference Sets, Space, Satellite Communications, Analytic Design


See Also
  • G. Oliveri, and A. Massa, "ADS-based array design for 2-D and 3-D ultrasound imaging," IEEE Trans. Ultrasonics Ferroelectrics Freq. Control, vol. 57, no. 7, pp. 1568-1582, Jul. 2010.
    doi:10.1109/TUFFC.2010.1587
  • G. Oliveri, and A. Massa, "Fully interleaved linear arrays with predictable sidelobes based on almost difference sets," IET Radar Sonar Navigat., vol. 4, no. 5, pp. 649-661, Oct. 2010.
    doi:10.1049/iet-rsn.2009.0186
  • G. Oliveri, P. Rocca, and A. Massa, "Interleaved linear arrays with difference sets," Electronics Letters , vol.46, no.5, pp.323-324, March 4 2010
    doi: 10.1049/el.2010.2255
  • G. Oliveri, L. Lizzi, F. Robol, and A. Massa, "Polarization-agile ADS-interleaved planar arrays," PIER, vol. 142, pp. 771-798, 2013.
    doi:10.2528/PIER13072702
   

 

 
 
The electromagnetic modeling of human tissues for biomedical purposes is a challenging task which usually requires large computational resources to take into account the complex properties and detailed structures of actual bodies. This is especially true if the modeling of tumor pathologies yielding anomalous microwave behaviour is of interest (as it happens for prostate cancer). In this framework, effective models have been recently proposed in order to enable the fast simulation of pathologies. Unfortunately, describing human bodies through traditional materials does not usually enable accurate modeling of the anomalous microwave response of pathological tissues. Accordingly, innovative electromagnetic models of biological tissues are of great importance in for the development of medical instruments working in the microwave range (e.g., tomography, radiotherapy).
   
Development of medical instruments working in microwave range, simulation and testing of innovative therapies (e.g., radiotherapy).

 


Electromagnetic Model Of The Abdomen
 
Members of the ELEDIA Research Center have developed innovative electromagnetic models for the effective simulation of biological tissues, which are based on the introduction of Metamaterial (MTM) inclusions in traditional numerical models. The motivation for this choice relies both on the microscopic structure of several tumor pathologies, which comprises "microfilaments" acting as resonators, as well as on the the observation of the macroscopic electromagnetic response of actual pathologies, which point out "EM focusing" properties typical of MTMs. The research activities carried out in this area have been focused on the mathematical modeling, implementation, and simulation of MTM-based models of biological tissues. Moreover, the exploitation of the developed models for inversion purposes is at present under investigation.

 

Simulation Of Traditional Model

 

Simulation Of Metamaterial-Based Model

Keywords: Metamaterials, Biological Tissue Modeling, Electromagnetic Interaction, Bioelectromagnetism


See Also
  • G. Oliveri, "Improving the reliability of frequency domain simulators in the presence of homogeneous metamaterials - a preliminary numerical assessment," Progress In Electromagnetics Research, Vol. 122, 497-518, 2012.
    doi:10.2528/PIER11100808
   

 

 
 
Next generation wireless communication systems allowing a suitable quality of service (QoS) and an enhanced security are needed to properly deal with complex scenarios characterized by multiple users as well as different standards. In this framework, smart antennas have been recognized as promising tools for an efficient management of the physical layer thanks to their capability to steer the main lobe of the beam pattern to track the desired signal and cancel the interferences. Unfortunately, the methodological difficulties in controlling fully-adaptive solutions prevented a widespread application of smart antennas in current wireless communications. Accordingly, the development of robust, high-performance and computationally efficient control algorithm to reconfigure the smart antenna system in real time are currently of great interest from the scientific and industrial viewpoint.
   
Wireless Cellular Networks, WIFI Systems, Mobile Communications

 



Smart Antenna Prototype

 



Example Of Pattern Reconfiguration
 
Members of the ELEDIA Research Center have developed several optimization-based methodologies for the control of smart antenna systems, which are based on the exploitation of Evolutionary Algorithms (EAs). Such approaches are motivated by the fact that the real-time optimal control of smart antennas can be easily recasted as an optimization problem where the fitness function depends on the SINR and is continuously updated at each time-step to take into account the changing interference/environment conditions. More specifically, the research activities carried out in the ELEDIA Research Center have been focused on the study, development, and prototyping of fully-adaptive smart antenna systems controlled through EAs such as the Particle Swarm Optimization. Moreover, the application of Memory-Enhanced control strategies has been investigated as well.
   

Keywords: Smart Antennas, Next Generation Wireless Communications, Evolutionary Algorithms, Particle Swarm Optimizer, Adaptive Arrays.


See Also
  • M. Benedetti, R. Azaro, A. Massa, "Memory Enhanced PSO-Based Optimization Approach for Smart Antennas Control in Complex Interference Scenarios," IEEE Trans. Antennas Propag., vol. 56, no. 7, pp. 1939-1947, July 2008
    doi:10.1109/TAP.2008.924717
  • M. Benedetti, G. Oliveri, P. Rocca, and A. Massa, "A fully-adaptive smart antenna prototype: ideal model and experimental validation in complex interference scenarios," Progress In Electromagnetics Research, vol. 96, 173-191, 2009.
    doi:10.2528/PIER09080904
  • M. Benedetti, R. Azaro, D. Franceschini, A. Massa, "PSO-Based Real-Time Control of Planar Uniform Circular Arrays," IEEE Antennas Wireless Propag. Lett., vol. 5, no. 1, pp. 545-548, Dec. 2006
    doi:10.1109/LAWP.2006.887553
  • M. Benedetti, R. Azaro, A. Massa, "Experimental validation of fully-adaptive smart antenna prototype," Electron. Lett., vol. 44, no. 11, pp. 661-662, May 2008
    doi:10.1049/el:20083689
  • M. Benedetti, G. Oliveri, M. Donelli, P. Rocca, A. Massa, "Experimental validation of a smart antenna system model," 2009 IEEE Antennas and Propagation Society International Symposium, pp.1-4, 1-5 June 2009
    doi:10.1109/APS.2009.5171473
  • M. Benedetti, P. Rocca, R. Azaro, A. Massa, "A fully-adaptive smart antenna prototype: Numerical modeling and experimental validation," 2008 IEEE Antennas and Propagation Society International Symposium, pp.1-4, 5-11 July 2008
    doi:10.1109/APS.2008.4619897
  • M. Benedetti, G. Oliveri, A. Massa, "Validation of a smart antenna prototype: Model and experiments," 2009 European Radar Conference, pp. 172-175, Sept. 30--2009-Oct. 2 2009
  • M. Benedetti, P. Rocca, M. Donelli, L. Lizzi, F. Viani, M. Martinelli, L. Ioriatti, A. Massa, "On the integration of smart antennas in Wireless Sensor Networks," 2008 IEEE Antennas and Propagation Society International Symposium, pp. 1-4, 5-11 July 2008
    doi:10.1109/APS.2008.4619571
  • L. Poli, P. Rocca, M. Salucci, and A. Massa, "Reconfigurable thinning for the adaptive control of linear arrays," IEEE Transactions on Antennas and Propagation, vol. 61, no. 10, pp. 5068-5077, Oct. 2013.
    doi:10.1109/TAP.2013.2272452
   

 

 
 
A modern antenna system should be able to maintain high quality communication links through a suitable modification of its operating conditions (i.e., radiation pattern and frequency band) to avoid jammings and interference signals from external sources. In this framework, time-modulated arrays have proved to be very flexible systems since they allow to reconfigure the radiated pattern just acting on the state (on/off) of a set of RF switches inserted in the feed network: thanks to these features, they can be considered as very good candidates for the new generation transmission systems controlled via software, the Software Defined Radio (SDR), since they allow to completely reconfigure the beam in a reliable and simple way through digital signals in function of the working scenario.
   
Satellite systems for wireless communications, radar applications, antenna for cellular base stations, earth observation

 

 

Pulse Sequence
 
Unfortunatly, the use of time-modulation technique in antenna array synthesis produces undesired radiations that correspond to a power wasting that affect array performance: to overcome this drawback, members of the ELEDIA Research Center have developed innovative strategies in order to get the suitable pulse sequences exciting the elements of the array that allow to synthesize a desired pattern at the work frequency minimizing the amount of wasted power in the sideband radiation. Several approaches based on the particle swarm optimization have been proposed in order to achieve the best compromise between the simplicity of reconfiguration of the system and the power loss, considering both communication and radar applications. Moreover, the possibility to exploit the sideband radiations for useful purposes have been investigated with the aim of synthesizing multi-beam patterns at different harmonic frequencies radiated by a single antenna system.

 

Antenna Sketch

 

Synthesized Beam Pattern

Keywords: Time-Modulation, Time-Modulated Arrays, Harmonic Beamforming, Adaptive Antenna Systems, Particle Swarm Optimization


See Also
  • L. Poli, P. Rocca, L. Manica, and A. Massa, "Handling sideband radiations in time-modulated arrays through particle swarm optimization," IEEE Trans. Antennas Propag., vol. 58, no. 4, pp. 1408-1411, Apr. 2010. 
    doi:10.1109/TAP.2010.2041165
  • P. Rocca, L. Manica, L. Poli, and A. Massa, "Synthesis of compromise sum-difference arrays through time-modulation," IET Radar Sonar Navigation, vol. 3, no. 6, pp. 630-637, Nov. 2009. 
    doi:10.1049/iet-rsn.2009.0058
  • L. Poli, P. Rocca, L. Manica, and A. Massa, "Time modulated planar arrays - analysis and optimisation of the sideband radiations," IET. Microw. Antennas & Propag., Vol. 4, Iss. 9, pp. 1165-1171, 2010. 
    doi:10.1049/iet-map.2009.0379
  • L. Poli, P. Rocca, L. Manica, and A. Massa, "Pattern synthesis in time-modulated linear arrays through pulse shifting," IET. Microw. Antennas & Propag., Vol. 4, Iss. 9, pp. 1157-1164, 2010. 
    doi:10.1049/iet-map.2009.0042
  • P. Rocca, L. Poli, G. Oliveri, and A. Massa, "Synthesis of time-modulated planar arrays with controlled harmonic radiations," J. Of Electromagn. Waves and Appl., vol. 24, no. 4, pp. 827-838, 2010. 
    doi:10.1163/156939310791036304
  • L. Poli, P. Rocca, G. Oliveri, and A. Massa, "Adaptive nulling in time-modulated linear arrays with minimum power losses," IET. Microw. Antennas Propag., vol. 5, no. 2, pp. 157-166, 2011. 
    doi:10.1049/iet-map.2010.0015
  • P. Rocca, L. Poli, G. Oliveri, and A. Massa, "Synthesis of Sub-Arrayed Time Modulated Linear Arrays Through a Multi-Stage Approach", IEEE Trans. Antennas Propag., vol. 59, no. 9, pp. 3246-3254, Sep. 2011. 
    doi:10.1109/TAP.2011.2161535
  • L. Poli, P. Rocca, G. Oliveri, and A. Massa, "Harmonic beamforming in time-modulated linear arrays through particle swarm optimization," IEEE Trans. Antennas Propag., vol. 59, no. 7, pp. 2538-2545, Jul. 2011. 
    doi:10.1109/TAP.2011.2152323
  • L. Poli, P. Rocca, G. Oliveri, and A. Massa, “Failure correction in time-modulated linear arrays,” IET Radar, Sonar & Navigation, vol. 8, no. 3, pp. 195-201, Mar. 2014.
    doi:10.1049/iet-rsn.2013.0027
  • P. Rocca, Q. Zhu, E. T. Bekele, S. Yang, and A. Massa, “4D arrays as enabling technology for cognitive radio systems,” IEEE Transactions on Antennas and Propagation - Special Issue on “Antenna Systems and Propagation for Cognitive Radio,” vol. 62, no. 3, pp. 1102-1116, Mar. 2014.
    doi:10.1109/TAP.2013.2288109
  • E. T. Bekele, L. Poli, M. D'Urso, P. Rocca, and A. Massa, "Pulse-shaping strategy for time modulated arrays - Analysis and design," IEEE Trans. Antennas Propag., vol. 61, no. 7, pp. 3525-3537, July 2013.
    doi:10.1109/TAP.2013.2256096
  • P. Rocca, L. Poli, G. Oliveri, and A. Massa, "Adaptive nulling in time-varying scenarios through time-modulated linear arrays," IEEE Antennas Wireless Propag. Lett., vol. 11, pp. 101-104, 2012.
    doi:10.1109/LAWP.2012.2183849
  • P. Rocca, L. Poli, and A. Massa, "Instantaneous directivity optimization in time-modulated array receivers," IET Microwaves, Antennas & Propagation, vol. 6, no. 14, pp. 1590-1597, Nov. 2012.
    doi:10.1049/iet-map.2012.0400
  • P. Rocca, L. Poli, L. Manica, and A. Massa, "Synthesis of monopulse time-modulated planar arrays with controlled sideband radiation," IET Radar, Sonar & Navigation, vol. 6, no. 6, pp. 432-442, 2012.
    doi:10.1049/iet-rsn.2012.0005
  • L. Poli, P. Rocca, and A. Massa, "Sideband radiation reduction exploiting pattern multiplication in directive time-modulated linear arrays," IET Microwaves, Antennas & Propagation, vol. 6, no. 2, pp. 214-222, 2012.
    doi:10.1049/iet-map.2011.0159
   

 

 
 
Healthcare systems require new technologies and services in order to provide high quality of life for elderly people with affordable costs. Towards this end, instruments able to continuously monitor the health status in a non-invasive way have to be implemented. In this framework, a fundamental objective is represented by the capability to allow independent living through automatic activity recognition and detection of anomalies in human behaviors.
   
Ambient Assisted Living Apartments, Hospitals, Nursing Homes, Rehabilitation Centers


Healthcare Monitoring

Warning Detection

Patient Position Monitoring

Activity Estimation
 

Members of the ELEDIA Research Center implemented the concept of passive healthcare monitoring exploiting the theoretical background of the inverse scattering theory and the advantages of distributed sensing through pervasive wireless infrastructures like wireless sensor networks (WSNs). The proposed monitoring approaches avoid the use of active and wearable devices thus reducing the system complexity and invasiveness. Elderly people and patients will benefit of the following passive monitoring characteristics:

  1. continuous activity monitoring that provides the user with versatility, safety and privacy;
  2. real-time detection of anomalies and warning signal transmission to a remote control unit;
  3. reduced system maintenance and complexity thanks to the absence of wearable sensors.

Research activities in the field of Healthcare monitoring have been mainly focused on the exploitation of information available through the widely diffused wireless infrastructures in order to provide simple and reliable monitoring services. The proposed procedures and algorithms have been verified both in controlled environments as well as in experimental test-beds.

 
 
 
 

Keywords: Healthcare, Ambient Assisted Living, Passive Monitoring, Activity Estimation, Wireless Sensor Networks


See Also
  • F. Viani, L. Lizzi, P. Rocca, M. Benedetti, M. Donelli, and A. Massa, "Object tracking through RSSI measurements in wireless sensor networks," Electronic Letters, vol. 44, no. 10, pp. 653-654, May 2008.
  • F. Viani, P. Rocca, M. Benedetti, G. Oliveri, and A. Massa, "Electromagnetic passive localization and tracking of moving targets in a WSN-infrastructured environment," Inverse Problems - Special Issue on "Electromagnetic Inverse Problems: Emerging Methods and Novel Applications," vol. 26, pp.1-15, 2010.
  • F. Viani, M. Donelli, P. Rocca, G. Oliveri, D. Trinchero, and A. Massa, "Localization, tracking and imaging of targets in wireless sensor networks," Radio Science, Vol. 46, No. 5, 2011.
  • F. Viani, L. Lizzi, M. Benedetti, M. Martinelli, L. Ioriatti, and A. Massa, "A RSSI-based method for real-time object localization in wireless sensor networks," Proc. European Conference on Wireless Sensor Networks 2008 (EWSN 2008), Bologna, Italy, Juanuary 30 - February 01, 2008.
  • F. Viani, M. Martinelli, L. Ioriatti, L. Lizzi, G. Oliveri, P. Rocca, and A. Massa, "Real-time indoor localization and tracking of passive targets by means of wireless sensor networks," Proc. 2009 IEEE AP-S International Symposium, Charleston, SC, USA, June 1-5, 2009.
  • F. Viani, M. Martinelli, L. Ioriatti, M. Benedetti, and A. Massa, "Passive real- time localization through wireless sensor networks," Proc. 2009 IEEE International Symposium on Geoscience and Remote Sensing, Cape Town, South Africa, July 13-17, 2009.
  • F. Viani, P. Rocca, G. Oliveri, and A. Massa, "Electromagnetic tracking of transceiver-free targets in wireless networked environments,'' Proc. 2011 European Conference on Antennas and Propagation (EuCAP2011), Rome, Italy, April 11-15, 2011.
  • F. Viani, F. Robol, A. Polo, P. Rocca, G. Oliveri, and A. Massa, "Wireless architectures for heterogeneous sensing in smart home applications - concepts and real implementations," Proc. IEEE, vol. 101, no. 11, pp. 2381-2396, Nov. 2013.
    doi:10.1109/JPROC.2013.2266858
   

 

 
 
The real-time knowledge of the direction of arrival (DOA) of the signals impinging on an antenna receiver enables the use of adaptive control algorithms suitable for limiting the effects of interferences and improve the performance of the wireless communication system. The use of LBE Algorithms provides high computational efficiency for real-time computing essential in many application scenarios.
   
Mobile wireless communications, time varying scenarios, localization and tracking systems

 

Mobile Communications 

System Architectur antenna e

P lanar Antenna Geometry
 

Approaches based on regression and classification have been developed by members of the ELEDIA Research Center exploiting the generalization capabilities of learning by example methodologies like neural networks (NN) and support vector machine (SVM) for the online DOA estimation of single and multiple signals. Multi-resolution strategies have been also suitably defined in order to further increase the performance of the proposed approaches, thus leading to

  1. enhanced angular resolution of the detection process in the region of incidence of the impinging signals;
  2. real-time evaluation of single and multiple DOAs through the definition of probabilities that a signal impinges on the antenna array. Both linear and planar geometries have been investigated;
  3. high robustness in case of noisy data thanks to the generalization capabilities of the adopted methods.

Research activities concerning the DOA estimation have been focused in the mathematical formulation of the training and testing procedures of LBE algorithms. The antenna geometries have been modeled and the corresponding received signals have been defined in order to efficiently evaluate the signal covariance matrix. Moreover, feature selection strategies have been introduced in order to extract as much information as possible from the available data.

Estimated 2-D DOAs
Image To be Changed

Keywords: Direction of Arrival Estimation, Learning by Examples, SVM, Mobile Communications


See Also
  • M. Donelli, F. Viani, P. Rocca, and A. Massa, "An innovative multi-resolution approach for DOA estimation based on a support vector classification," IEEE Transactions on Antennas and Propagation, vol. 57, no. 8, pp. 2279-2292, August 2009.
  • L. Lizzi, F. Viani, M. Benedetti, P. Rocca, and A. Massa, "The M-DSO-ESPRIT method for maximum likelihood DoA estimation," Progress in Electromagnetic Research, vol. 80, pp. 477-497, 2008.
  • M. Donelli, R. Azaro, L. Lizzi, F. Viani, and A. Massa, "A SVM-based multi-resolution procedure for the estimation of the DOAs of interfering signals in a communication system," Proc. European Conference on Antennas & Propagation (EuCAP), Nice, France, 6-10 November, 2006.
  • M. Benedetti, P. Rocca, M. Donelli, L. Lizzi, F. Viani, M. Martinelli, L. Ioriatti and A. Massa, "On the integration of smart antennas in wireless sensor networks," Proc. 2008 IEEE AP -S International Symposium, San Diego, USA, July 5-11, 2008.
   

 

 
 
Crowds monitoring can be of critical relevance, expecially when dealing with large scale locations, such as airports, supermarkets and stadiums, where crowds tend to appear for many different reasons. The use of automated techniques for monitoring crowds, such as estimating a crowd’s density, tracking its movements (and even observing its behaviour) is nowadays necessary in a large number of applications. In fact, areas where people are likely to cluster (e.g. an airport) need careful observation to ensure crowd safety (i.e. ensuring a fast and safe evacuation in case of danger, distributing people over all the available security doors). Crowd density estimation and detection can be of fundamental relevance also when dealing with marketing strategies and investigations, where the ability to observe people concentrations (e.g. inside a supermarket, in correspondence to the exposition of a brand new product) directly translates into an analysis of people main interests. Moreover, in some applications people monitoring through classical video surveillance systems (e.g. CCTV) may not be the proper choice, or in some cases it may even be not feasible (e.g for privacy reasons). In those scenarios, it would be of great interesest the use of the avaliable wireless infrastructure to infer informations about crowd density and movements, by simply analyzing the electromagnetic field distribution inside a wide area.
   
Large scale locations, airports, supermarkets, stadiums


Airport

Supermarket
 
Members of the ELEDIA Research Center have developed several techniques for the simulation of the electromagnetic field distribution in very-large scale crowded locations. The basic idea is to apply the concepts of Device-Free Localization (DFL) and Tracking when dealing with a big number of targets, which are spread over a wide area (indoor or outdoor). As a matter of fact, people inside a scenario under test interact with the electromagnetic signals transmitted by the infrastructured wireless devices (e.g. the Wi-Fi access points), thus modifying the received signal strength by each device. The crowd detection and tracking problem can then be reformulated in terms of a simplified electromagnetic inverse scattering problem, which is carried out by means of a learning-by-example (LBE) strategy.
   
E-Field distribution over a wide area
Probability map of crowd density inside a wide area

Keywords: Crowd Density Estimation, Device-Free Passive Localization, Crowd Detection, Crowd Tracking


See Also
  • F. Viani, L. Lizzi, P. Rocca, M. Benedetti, M. Donelli, and A. Massa, "Object tracking through RSSI measurements in wireless sensor networks," Electronics Letters, vol. 44, no. 10, pp. 653-654, May 8 2008
    doi: 10.1049/el:20080509
  • F. Viani, G. Oliveri, and A. Massa, "Real-time tracking of transceiver-free objects for homeland security," European Radar Conference (EuRAD 2009), pp.621-624, Sept. 30 2009-Oct. 2 2009
  • F. Viani, M. Donelli, M. Salucci, P. Rocca, and A. Massa, "Opportunistic exploitation of wireless infrastructures for homeland security," 2011 IEEE International Symposium on Antennas and Propagation (APSURSI), pp. 3062-3065, 3-8 July 2011
    doi: 10.1109/APS.2011.5997177
  • F. Viani, M. Salucci, P. Rocca, G. Oliveri, A. Massa, "A multi-sensor WSN backbone for museum monitoring and surveillance," 6th European Conference on Antennas and Propagation (EUCAP 2012), Prague, CZ, pp. 51-52, 26-30 Mar. 2012.
    doi:10.1109/EuCAP.2012.6206050
  • G. Menduni, F. Viani, F. Robol, E. Giarola, A. Polo, G. Oliveri, P. Rocca, and A. Massa, "A WSN-based architecture for the E-Museum - The experience at 'Sala dei 500' in Palazzo Vecchio (Florence)," IEEE Antennas and Propagation Society International Symposium (APSURSI 2013), Orlando, FL, United States, pp. 1114-1115, 7-13 Jul. 2013.
    doi:10.1109/APS.2013.6711217
   

 

Subcategories