Marco De Piante

In-Vehicle Power Line Communication: Differences and Similarities Among the In-Car and the In-Ship Scenarios

This article deals with power line communication (PLC) in the context of invehicle data networks. This technology can provide high-speed data connectivity via the exploitation of the existing power network, with clear potential benefits in terms of cost and weight reduction. The focus is on two scenarios: an electric car (EC) and a cruise ship. An overview of the wiring infrastructure and the network topology in these two scenarios is provided. The main findings reported in the literature related to the channel characteristics are reported. Noise is also assessed with emphasis on the EC context. New results from the statistical analysis of measurements made in a compact EC and in a large cruise ship are also shown. The channel characteristics are analyzed in terms of average channel gain (ACG), delay spread (DS), coherence bandwidth (CB), and achievable transmission rate. Finally, an overall comparison is made, highlighting similarities and differences while taking into account the conventional combustion engine car and the largely investigated in-home scenario.

On Impedance Matching in a Power-Line-Communication System

Impedance matching plays an important role in a power-line-communication system. We investigate the effect on the signal-to-noise ratio at the receiver and on the system capacity of three different impedance matching criteria at the transmitter, assuming broad-band communication. We show that optimal impedance matching shall maximize the amplitude of the signal voltage at the channel input port. Since the line impedance exhibits highly frequency-dependent behavior, simplified impedance matching criteria are also proposed.

On modeling the sporadic impulsive noise rate within in-home power line networks

The paper proposes a methodology to model the impulse rate of sporadic impulsive noise, namely the impulsive noise that is generated by the transients during the on/off switching of electrical appliances. In particular, it is proposed to exploit the publicly available datasets of power consumption measurements campaigns to derive the instants when a switching on/off event occurs. The statistics of the impulse rate is derived considering the data gathered during a six-month measurement in one of the houses of the GREEND dataset. Furthermore, to define the set of appliances that generate sporadic impulsive noise within the considered house, a noise measurement campaign at the source the corresponding analysis was carried out.

Characteristics of the PLC channel: Reciprocity, symmetry and port decoupling for impedance matching

This paper analyzes the reciprocity, symmetry and port decoupling effect in real home PLC networks. The reciprocity has an impact on the fact that the input and output ports of a PLC link are decoupled, and the study on the symmetry can explain the reason for the decoupling effect. The analysis of experimental data in the band 2-100 MHz shows that the PLC channel is reciprocal and that the input-output ports are largely decoupled. In turn, the port decoupling property implies that impedance matching at the transmitter and receiver ports can be implemented independently one from the other. That is, the choice of the receiver impedance does not have effect on the choice of the transmitter impedance and vice versa, in home broad band PLC systems.

Impedance matching and channel capacity in power line communication systems

In this paper, the effects of impedance matching in the PLC systems in terms of capacity are investigated. Two different matching methods at the transmitter port are introduced. Since the punctual impedance matching is a difficult task for the electronics, firstly we illustrate an algorithm useful to measure the input PLC channel impedance at both the transmitter and the receiver sides. This is of fundamental importance for the matching operations. Once the input impedances are retrieved, we compare the achievable system capacity obtainable with the transmitter impedance optimized applying the considered matching criteria. Furthermore, the channel capacity loss with simplified and more implementable transmitter impedance profiles are investigated.

Transmitter front-end for impulsive broad band power line communications

Power Line Communication (PLC) systems have attracted considerable attention since they enable the delivery of services in several domains without requiring new wires. Smart homes and smart grids are good candidates for the application of PLC. In the context of smart homes, both high speed and low speed PLC networks, namely broad band PLC (BB-PLC) and narrow band PLC (NB-PLC), can find application for home networking, for multimedia/entertainment services, for home automation and energy management. Currently, both BB-PLC and NB-PLC use multicarrier modulation. It is relevant to conceive alternative modulation techniques that can provide higher date rates without, possibly, increasing complexity. Impulsive ultra wide band modulation can offer such benefits especially if simple implementations are developed. In this paper, we focus on the hardware design of the front-end stage of an impulsive based PLC system. The front-end comprises a novel pulse generator, a pulse shaper and a coupler to inject the signal into the mains voltage network. We study the physical constraints to generate pulses at a certain rate, with a certain bandwidth and with a certain power. In particular, in impulsive modulation, while the average power spectral density is small, the peak power is a severe requirement for conventional amplifiers.

RF architecture for wireless sensor network coverage improvement

In this paper, we describe an RF architecture to Improve coverage and performance of a wireless sensor network. We consider IEEE 802.15.4 ZigBee devices to realize a building automation and energy management system. ZigBee operates typically at 2.4 GHz and may suffer of coverage problems in harsh propagation environments as in large buildings. In order to improve performance, we propose the use of lower frequencies. In particular, the 800 MHz and 400 MHz spectrum can be considered still fulfilling European frequency allocation norms. We describe the design of the required RF front-end. An hardware prototype has been realized. We show that it can be used as a plug-in module for existing ZigBee devices operating at 800 MHz that enables the transmission at 400 MHz and 800 MHz in a selective mode.

Broadband PLC field trial on a compact electric vehicle

Power line communication (PLC) is a valuable solution to limit the amount of wiring, reduce the weight and thus increase the performance of electric vehicles. Basically, PLC removes the need of a dedicated wiring infrastructure for the data exchange by signaling over the power delivery cables. This work shows the potentialities of such technology reporting the performance of commercially available PLC devices designed for in-home networks and adapted for the in-vehicle scenario. Further, it provides an insight on the channel and noise characteristics and proves the robustness of PLC, a technology that is able to cope with high attenuation, large periodic noise and disruptive impulses. Finally, an application example where a rear camera is connected via PLC to a display placed on the dashboard of the vehicle is described.

People navigation system in confined spaces

This paper describes the architecture of a navigation system for people that need to be guided through indoor environments, e.g., public buildings, hospitals, where navigation is very critical. The system has to provide both navigation and context aware information to people that may be in difficult emotive state as it happens to patients and visitors in a hospital. This system is under development within the POR/FESR Project EasyMob, funded by Friuli Venezia Giulia region of Italy. In this paper we will first present the EasyMob system approach and discuss requirements and challenges. Then, we will focus on the navigation technology and we will describe the solutions that have been developed.