Luca De Vito

A review of wideband spectrum sensing methods for Cognitive Radios

The paper presents a review of the scientific literature dealing with the wideband detection of signals. Such problem is critical in Cognitive Radios (CRs), as it allows identifying the portions of the radio spectrum, where the CR can transmit. The relevant literature has been classified into three main approaches to the wideband spectrum sensing problem. A first approach considers the observed wideband as a partition in which the width of each sub-band is fixed and known. This approach pays attention to the joint detection of the occupied and free sub-bands. A second approach jointly estimates the boundaries of the sub-bands and the power density level inside each sub-band. Finally, a third approach concentrates the attention to the estimation of the sub-band boundaries. The concepts of compressed sensing and cooperative sensing have been presented, and, several papers basing on these concepts have been analyzed, too.

Measurements and sensors for motion tracking in motor rehabilitation

This paper presents a brief overview of the commercial solutions and the research proposals for measuring the patients movements, and is organized as follows. In Section 1, a review of laboratory measurement equipment for the patients mobility evaluation will be described. In Sections 2 and 3, some proposals of portable measurement systems, used to monitor the patient or track his/her progresses during the treatment at home and in clinical environments, are presented and discussed. The measurement methods presented are marker-based motion capture and analysis systems, marker-less motion capture and analysis systems, robot-based and exoskeleton systems, vision systems and virtual reality, and personal motion measurement systems based on sensor networks.

Bayesian Calibration of a Lookup Table for ADC Error Correction

This paper presents a new method for the correction of nonlinearity errors in analog-to-digital converters (ADCs). The method has been designed to allow a self-calibration in systems where an internal signal can be generated, such as base stations for mobile communications. The method has been implemented and tested in simulation on the behavioral model of commercial ADCs and on a hardware setup composed by a data acquisition board and a distorting circuit

Wireless Sensor Network for traffic safety

The paper presents the design and implementation of an innovative Wireless Sensor Network (WSN) for traffic safety measurements. The research aims to create a Wireless Active Guardrail System (WAGS) which can provide user-friendly and low-delay safety warning signs to travelers in presence of possible collisions between vehicles and guardrails. The proposed WAGS uses advanced sensing and networking technologies. The general architecture and two sensor nodes for safety measurements are described in details.

Eigenvalue-based signal detector for an automatic modulation classifier

This paper describes the design and the experimental validation of a preprocessing block for an automatic modulation classifier. The preprocessing block performs two main tasks. The former consists of dividing the spectrum in sub-bands, while the latter has the aim of sensing the signal presence, in each sub-band. The signal sensing is provided by a method, based on the eigenvalues of the covariance matrix of the acquired record. Several experimental tests with simulated and actual signals, for different values of the Signal to Noise Ratio, have been performed showing very high detection percentages.

Wireless Active Guardrail System for environmental measurements

The paper presents the design and implementation of a Wireless Active Guardrail System (WAGS), that adds to the typical passive protection of guardrails the capability of monitoring both traffic and environment along the roads. The general overview of a WAGS, intended to be applied on highways, is presented and the measured quantities are discussed. The architecture of a sensor node for environmental monitoring experimentally validated in laboratory is presented and future improvements and features are suggested.

A GNU radio-based signal detector for cognitive radio systems

This paper deals with the hardware and software architecture of a signal detector prototype. It is able to observe a wide band and to find, in such band, the empty or occupied channels. It is intended to be used either in telecommunication devices or in spectrum monitoring instruments working in the new scenarios of telecommunications, where a flexible and dynamic spectrum management will be introduced. The signal detector has been validated on simulated and emulated signals showing high detection percentages even with low signal to noise ratios.

Spectrum segmentation for wideband sensing of radio signals

Spectrum sensing is a key factor for either the development of Cognitive Radio or the implementation of instruments able to automatically monitor the radio spectrum. Within the process of spectrum sensing, segmentation aims to detect the boundaries of the transmission channels in a wide frequency range. The paper proposes a new spectrum segmentation method characterized by low processing time. The developed histogram-based method is described in the paper. Several experimental tests on emulated and actual signals are presented to prove the effectiveness of the method in terms of success percentage, processing time.

Experimental comparison of orientation estimation algorithms in motion tracking for rehabilitation

This paper presents the experimental comparison of data fusion algorithms for human motion tracking in rehabilitation, using Inertial Measurement Units. Three algorithms for orientation estimation, taken from the scientific literature in the field, have been selected and their capability of accurately tracking the angle of a selected joint has been evaluated. In particular, two phases of experimental analysis have been carried out. The former, in laboratory, was directed to verify the capability of the algorithms of tracking a fixed angle range. In the latter, carried out in a rehabilitation center, the results obtained by the considered algorithms have been compared with those provided by a vision-based motion tracking system.

Wireless active guardrail for traffic safety: Preliminary tests of speed and proximity measurement

The paper presents the preliminary results of the characterization phase of the speed and proximity measurement systems, intended to be integrated in a Wireless Active Guardrail System (WAGS). The main aim of the work is to validate the data acquisition functionalities of the proposed measurement systems in laboratory conditions by assessing the contribution to the measurement uncertainty of the signal conditioning hardware, as well as of the software procedures.