Συντάχθηκε 31-07-2013 11:21
από Eleni Stamataki
Email συντάκτη: estamataki<στο>tuc.gr
Ενημερώθηκε:
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Ιδιότητα: σύνταξη/αποχώρηση υπάλληλος.
Σχολή Ηλεκτρονικών Μηχανικών και Μηχανικών Υπολογιστών
Πρόγραμμα Μεταπτυχιακών Σπουδών
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΑΤΡΙΒΗΣ
ΚΙΜΙΩΝΗ ΙΩΑΝΝΗ
με θέμα
Bistatic Scatter Radio for Increased-range Environmental Sensing
Παρασκευή 2 Αυγούστου 2013, 10πμ
Αίθουσα 2041, Κτίριο Επιστημών, Πολυτεχνειούπολη
Εξεταστική Επιτροπή
Επίκουρος Καθηγητής Άγγελος Μπλέτσας (επιβλέπων)
Αναπληρωτής Καθηγητής Γεώργιος Ν. Καρυστινός
Καθηγητής Αθανάσιος Π. Λιάβας
Abstract
For environmental sensing applications that require dense deployments, scatter radio is a promising communication scheme. Since modulation is achieved by means of reflection, very low-cost and low-power RF front-ends are required. However, its use in sensor networks has been limited, since commercial scatter radio applications, like RFID, are limited to ranges of a few meters. To overcome this limitation, bistatic scatter radio architectures are exploited, that boost the operating range up to 130 meters with only 20 milliwatts of carrier power. The carrier emitter is detached from the reader to form a cell wherein sensors-modulators may reside and communicate efficiently. As conventional radio receivers are not directly applicable, the complete signal model is derived (i.e. not assumed) for the bistatic scatter radio link, by exploiting both communication theory and microwave theory. A simple on-off-keying (OOK) modulation scheme appropriate for the bandwidth- limited regime is presented with non-linear receivers that overcome the carrier frequency offset between the carrier emitter and the reader. Also, noncoherent frequency-shift-keying (FSK) is described for the bandwidth-limited regime, that accounts for sensor multiple access through frequency division multiplexing. This scheme is shown to achieve a robust bit-error-rate (BER) performance at the receiver, immune to channel conditions changes and is therefore convenient for the low-bitrate nature of environmental sensing. This work discusses the impact of important microwave parameters such as the antenna structural mode on the receiver performance. It is shown that tags and their corresponding receivers should be jointly designed to maximize BER performance. Outdoor experimental measurements with a custom setup prove the long-range capability of bistatic scatter radio architectures.
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ΚΙΜΙΩΝΗΣ ΙΩΑΝΝΗΣ.doc
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