2015 IEEE International Workshop on Measurements & Networking (M&N), 2015
In this paper, a 2.5D positioning system is analyzed, based on Received Signal Strength (RSS) mea... more In this paper, a 2.5D positioning system is analyzed, based on Received Signal Strength (RSS) measurements, collected from narrowband RF transmissions. The mobile node of the considered system uses multiple closely spaced receivers, collecting RSS measurements and combining them to mitigate multipath effects. Using simulations and optical approximation, the effect of antenna directivity on the positioning accuracy is analyzed. Moreover, a simple iterative method is proposed, that further improves the accuracy obtained using the multipath mitigation technique.
IEEE Transactions on Instrumentation and Measurement, 2013
ABSTRACT This paper describes the design and realization of a 5.6-GHz ultrawide-bandwidth-based p... more ABSTRACT This paper describes the design and realization of a 5.6-GHz ultrawide-bandwidth-based position measurement system. The system was entirely made using off-the-shelf components and achieves centimeter-level accuracy in an indoor environment. It is based on asynchronous modulated pulse round-trip time measurements. Both system level and realization details are described along with experimental results including estimates of measurement uncertainties.
IEEE Transactions on Instrumentation and Measurement, 2013
ABSTRACT Wireless sensor networks are becoming widely diffused because of the flexibility and sca... more ABSTRACT Wireless sensor networks are becoming widely diffused because of the flexibility and scalability they offer. However, distributed measurements are significant only if the readout is coupled to time information. For this reason, network-wide time synchronization is the main concern. The objective of this paper is to exploit a very simple hardware implementation of an IR-UWB radio for realizing an accurate synchronization system for wireless sensors. The proposed solution relies on commercial-off-the-shelf discrete electronic components (rather than on specialized transceivers). It is designed for providing accurate timestamping of the packet time of arrival (TOA) to an adder-based tunable clock, which tracks the network time reference. The comprehensive set of experimental results based on prototypes, shows a TOA detection error with a standard deviation well below 1 ns. On the other hand, in the FPGA-based prototype, the synchronization performance reaches an overall synchronization error of few nanoseconds. Finally, in order to highlight the tradeoff between timestamping accuracy, clock stability, and synchronization performance, some additional simulations have been carried out: a synchronization error in the order of 1 ns is possible, if good local oscillator sources are available in the nodes and if the adjustable clock has a sufficient resolution.
2019 IEEE International Symposium on Measurements & Networking (M&N)
In this paper, application of the Bluetooth Low Energy (BLE) protocol is investigated, with the a... more In this paper, application of the Bluetooth Low Energy (BLE) protocol is investigated, with the aim of achieving time-synchronization for Time of flight (ToF) measurements-based positioning. The proposed approach may provide a competitive solution for portable and wearable devices, medical devices, home automation systems, and sensor-based low-power systems for the Internet of Things (IoT). A simulation model was implemented for a 2D scenario using ToF measurements, considering a delay model and simulating an Additive White Gaussian Noise (AWGN) channel. The communication latencies were realistically modeled, using a dataset of measurements collected from a real device. The results show an achievable positioning accuracy of about 1 mm, significantly improving with respect to an unsynchronized Time Difference of Arrival (TDoA) positioning system, supervised using a BLE protocol [1]. The results demonstrate the feasibility of accurate and low-cost positioning systems, based on ToF measurements on ultrasound transmissions and triggered by BLE RF transmissions.
In this paper we present a hand tracking system based on magnetic positioning. A single magnetic ... more In this paper we present a hand tracking system based on magnetic positioning. A single magnetic node is mounted on each fingertip, and two magnetic nodes on the back side of the hand. A fixed array of receiving coils is used to detect the magnetic field, from which it is possible to infer position and orientation of each magnetic node. A kinematic model of the whole hand has been developed. Starting from the positioning data of each magnetic node, the kinematic model can be used to calculate position and flexion angle of each finger joint, plus the position and orientation of the hand in space. Relying on magnetic fields, the hand tracking system can work also in nonline-of-sight conditions. The gesture reconstruction is validated by comparing it with a commercial hand tracking system based on a depth camera. The system requires a small amount of electronics to be mounted on the hand. This would allow building a light and comfortable data glove that could be used for several purpos...
An appropriate choice of the computing devices employed in digital signal processing applications... more An appropriate choice of the computing devices employed in digital signal processing applications requires to characterize and to compare various technologies, so that the best component in terms of cost and performance can be used in a given system design. In this paper, a benchmark strategy is presented to measure the performances of various types of digital signal processing devices. Although different metrics can be used as performance indexes, Fast Fourier Transform (FFT) computation time and Real-Time Bandwidth (RTBW) have proved to be excellent and complete performance parameters. Moreover, a new index, measuring the architectural efficiency in computing FFT, is introduced and explained. Both parameters can be used to compare several digital signal processing technologies, thus guiding designers in optimal component selection.
This paper investigates the effects of Integral Non-Linearity (INL) on the performances of both A... more This paper investigates the effects of Integral Non-Linearity (INL) on the performances of both A/D converters and Digital Communication Systems, which exploit Direct Digital Modulation. The performances of both PCM and Sigma-Delta converters affected by INL are considered and compared. Then, the effects of INL upon the BER performances of an OFDM system are evaluated and modeled. The accuracy of the theoretical model is discussed with respect to the ADC resolution and INL levels. It is shown that a multibit Sigma-Delta converter, operating at a low oversampling ratio, may outperform PCM converters.
2018 IEEE International Systems Engineering Symposium (ISSE), 2018
We illustrate a devised and implemented data acquisition system (DAQ) for a magnetic positioning ... more We illustrate a devised and implemented data acquisition system (DAQ) for a magnetic positioning system (MPS) that is currently under development. This system aims to track position and attitude of an active transmitting coil (TX) supplied with a sinusoidal current, whose generated magnetic field induces tensions on an array of passive receiving coils (RX). The DAQ system has to acquire voltages at all RX coils. These signals are then processed to estimate the TX coordinates, according to a mathematical model in order. In order to track the TX in real-time with a good resolution, voltages have to be measured simultaneously on all RXs. To this aim, we opted for a distributed architecture of microcontroller units (MCU). Each selected MCU has four analog-to-digital converters (ADC) that can work in parallel. Moreover multiple MCUs can be triggered simultaneously by a single MCU in a master-slave configuration. We used MCUs with a fast dual-core CPU. Each unit can directly process its o...
Parametric estimation of signals, based on quantized data, is often carried out by means of least... more Parametric estimation of signals, based on quantized data, is often carried out by means of least squares (LS) or averaging techniques. Such an approach often leads to optimal performance, resulting in almost unbiased estimators when the quantization error can approximately be modeled as an additive white Gaussian noise, or when other additive white Gaussian noise sources are larger than the quantization error. When such hypotheses are not satisfied, however, averaging may produce suboptimal, and biased estimators. In such a case, maximum likelihood or quantile based identification techniques can be shown to lead to more performing estimators, mostly unbiased and with a lower mean square error than that of an LS estimator. A software tool is presented, capable of estimating a DC level, a DC level corrupted by Additive White Gaussian Noise (AWGN), and sinewave parameters when the frequency is known, using data quantized by a nonuniform ADC.
2015 IEEE International Workshop on Measurements & Networking (M&N), 2015
In this paper, a 2.5D positioning system is analyzed, based on Received Signal Strength (RSS) mea... more In this paper, a 2.5D positioning system is analyzed, based on Received Signal Strength (RSS) measurements, collected from narrowband RF transmissions. The mobile node of the considered system uses multiple closely spaced receivers, collecting RSS measurements and combining them to mitigate multipath effects. Using simulations and optical approximation, the effect of antenna directivity on the positioning accuracy is analyzed. Moreover, a simple iterative method is proposed, that further improves the accuracy obtained using the multipath mitigation technique.
IEEE Transactions on Instrumentation and Measurement, 2013
ABSTRACT This paper describes the design and realization of a 5.6-GHz ultrawide-bandwidth-based p... more ABSTRACT This paper describes the design and realization of a 5.6-GHz ultrawide-bandwidth-based position measurement system. The system was entirely made using off-the-shelf components and achieves centimeter-level accuracy in an indoor environment. It is based on asynchronous modulated pulse round-trip time measurements. Both system level and realization details are described along with experimental results including estimates of measurement uncertainties.
IEEE Transactions on Instrumentation and Measurement, 2013
ABSTRACT Wireless sensor networks are becoming widely diffused because of the flexibility and sca... more ABSTRACT Wireless sensor networks are becoming widely diffused because of the flexibility and scalability they offer. However, distributed measurements are significant only if the readout is coupled to time information. For this reason, network-wide time synchronization is the main concern. The objective of this paper is to exploit a very simple hardware implementation of an IR-UWB radio for realizing an accurate synchronization system for wireless sensors. The proposed solution relies on commercial-off-the-shelf discrete electronic components (rather than on specialized transceivers). It is designed for providing accurate timestamping of the packet time of arrival (TOA) to an adder-based tunable clock, which tracks the network time reference. The comprehensive set of experimental results based on prototypes, shows a TOA detection error with a standard deviation well below 1 ns. On the other hand, in the FPGA-based prototype, the synchronization performance reaches an overall synchronization error of few nanoseconds. Finally, in order to highlight the tradeoff between timestamping accuracy, clock stability, and synchronization performance, some additional simulations have been carried out: a synchronization error in the order of 1 ns is possible, if good local oscillator sources are available in the nodes and if the adjustable clock has a sufficient resolution.
2019 IEEE International Symposium on Measurements & Networking (M&N)
In this paper, application of the Bluetooth Low Energy (BLE) protocol is investigated, with the a... more In this paper, application of the Bluetooth Low Energy (BLE) protocol is investigated, with the aim of achieving time-synchronization for Time of flight (ToF) measurements-based positioning. The proposed approach may provide a competitive solution for portable and wearable devices, medical devices, home automation systems, and sensor-based low-power systems for the Internet of Things (IoT). A simulation model was implemented for a 2D scenario using ToF measurements, considering a delay model and simulating an Additive White Gaussian Noise (AWGN) channel. The communication latencies were realistically modeled, using a dataset of measurements collected from a real device. The results show an achievable positioning accuracy of about 1 mm, significantly improving with respect to an unsynchronized Time Difference of Arrival (TDoA) positioning system, supervised using a BLE protocol [1]. The results demonstrate the feasibility of accurate and low-cost positioning systems, based on ToF measurements on ultrasound transmissions and triggered by BLE RF transmissions.
In this paper we present a hand tracking system based on magnetic positioning. A single magnetic ... more In this paper we present a hand tracking system based on magnetic positioning. A single magnetic node is mounted on each fingertip, and two magnetic nodes on the back side of the hand. A fixed array of receiving coils is used to detect the magnetic field, from which it is possible to infer position and orientation of each magnetic node. A kinematic model of the whole hand has been developed. Starting from the positioning data of each magnetic node, the kinematic model can be used to calculate position and flexion angle of each finger joint, plus the position and orientation of the hand in space. Relying on magnetic fields, the hand tracking system can work also in nonline-of-sight conditions. The gesture reconstruction is validated by comparing it with a commercial hand tracking system based on a depth camera. The system requires a small amount of electronics to be mounted on the hand. This would allow building a light and comfortable data glove that could be used for several purpos...
An appropriate choice of the computing devices employed in digital signal processing applications... more An appropriate choice of the computing devices employed in digital signal processing applications requires to characterize and to compare various technologies, so that the best component in terms of cost and performance can be used in a given system design. In this paper, a benchmark strategy is presented to measure the performances of various types of digital signal processing devices. Although different metrics can be used as performance indexes, Fast Fourier Transform (FFT) computation time and Real-Time Bandwidth (RTBW) have proved to be excellent and complete performance parameters. Moreover, a new index, measuring the architectural efficiency in computing FFT, is introduced and explained. Both parameters can be used to compare several digital signal processing technologies, thus guiding designers in optimal component selection.
This paper investigates the effects of Integral Non-Linearity (INL) on the performances of both A... more This paper investigates the effects of Integral Non-Linearity (INL) on the performances of both A/D converters and Digital Communication Systems, which exploit Direct Digital Modulation. The performances of both PCM and Sigma-Delta converters affected by INL are considered and compared. Then, the effects of INL upon the BER performances of an OFDM system are evaluated and modeled. The accuracy of the theoretical model is discussed with respect to the ADC resolution and INL levels. It is shown that a multibit Sigma-Delta converter, operating at a low oversampling ratio, may outperform PCM converters.
2018 IEEE International Systems Engineering Symposium (ISSE), 2018
We illustrate a devised and implemented data acquisition system (DAQ) for a magnetic positioning ... more We illustrate a devised and implemented data acquisition system (DAQ) for a magnetic positioning system (MPS) that is currently under development. This system aims to track position and attitude of an active transmitting coil (TX) supplied with a sinusoidal current, whose generated magnetic field induces tensions on an array of passive receiving coils (RX). The DAQ system has to acquire voltages at all RX coils. These signals are then processed to estimate the TX coordinates, according to a mathematical model in order. In order to track the TX in real-time with a good resolution, voltages have to be measured simultaneously on all RXs. To this aim, we opted for a distributed architecture of microcontroller units (MCU). Each selected MCU has four analog-to-digital converters (ADC) that can work in parallel. Moreover multiple MCUs can be triggered simultaneously by a single MCU in a master-slave configuration. We used MCUs with a fast dual-core CPU. Each unit can directly process its o...
Parametric estimation of signals, based on quantized data, is often carried out by means of least... more Parametric estimation of signals, based on quantized data, is often carried out by means of least squares (LS) or averaging techniques. Such an approach often leads to optimal performance, resulting in almost unbiased estimators when the quantization error can approximately be modeled as an additive white Gaussian noise, or when other additive white Gaussian noise sources are larger than the quantization error. When such hypotheses are not satisfied, however, averaging may produce suboptimal, and biased estimators. In such a case, maximum likelihood or quantile based identification techniques can be shown to lead to more performing estimators, mostly unbiased and with a lower mean square error than that of an LS estimator. A software tool is presented, capable of estimating a DC level, a DC level corrupted by Additive White Gaussian Noise (AWGN), and sinewave parameters when the frequency is known, using data quantized by a nonuniform ADC.
Uploads
Papers by Antonio Moschitta