Search results for "wireless communication"
showing 5 items of 25 documents
An Energy-Autonomous Wireless Sensor with Simultaneous Energy Harvesting and Ambient Light Sensing
2021
Wireless sensor nodes (WSNs) are generally powered by batteries, which results in a substantial limitation to the places where the nodes can be installed, to the maximum number of deployable devices, and to the node lifetime. To meet the demand for Internet-of-Things (IoT) applications that require a large number of maintenance-free, low cost, wireless sensor nodes, this paper proposes a wireless sensor platform with a single photovoltaic transducer that performs the dual role of harvesting energy and sensing ambient light. This dual use allows even smaller and cheaper nodes that do not require any form of supporting external power, with a reduced component count. The device implements off-…
Maximum Lifetime Problem in Sensor Networks with Limited Channel Capacity
2016
We analyze the maximum lifetime problem in sensor networks with limited channel capacity for multipoint-to-multipoint and broadcast data transmission services. For the transmission model in which the transmitter adjust the power of its radio signal to the distance to the receiver we propose a new Signal to Interference plus Noise Ratio function and use it to modify the Shannon-Hartley channel capacity formula. We show, that in order to achieve an optimal data transmission regarding considered the maximum lifetime problem we cannot allow for any interference of signals. For considered transmission model and the modified capacity formula we solve the maximum lifetime problem in one dimensiona…
Community divided : adaptation and aversion towards the spent nuclear fuel repository in Eurajoki and its neighbouring municipalities
2010
On the evaluation of an optical OFDM radio over FSO system with IM-DD for high-speed indoor communications
2017
En aquest article es proposa un nou sistema híbrid de ràdio sobre fibra (RoF) i òptica d’espai lliure (FSO) basat en la transmissió de senyals òptics OFDM (OOFDM) per proporcionar enllaços de comunicació sense fils òptics d’alta capacitat. Es proposa un esquema de transmissió de baix cost basat en IM-DD per simplificar i reutilitzar la infraestructura existent per desplegar un enllaç FSO d’alt ample de banda. Aquest article mostra els resultats experimentals basats en la implementació de l'esquema proposat sota una transmissió digital OOFDM de 16 QAM a través de 10 km de fibra monomode (SMF) i enllaç FSO de 300 mm. Els resultats mostren la viabilitat de desplegar un sistema de comunicació d…