Bletsas AggelosΜπλετσας ΑγγελοςKabianakis EleftheriosΚαμπιανακης Ελευθεριος2024-10-312024-10-3120142014-07-25Eleftherios Kabianakis, "Scatter radio sensor network with analog frequency modulation principles", Master Thesis, School of Electronic and Computer Engineering, Technical University of Crete, Chania, Greece, 2014Ελευθέριος Καμπιανάκης, "Scatter radio sensor network with analog frequency modulation principles", Μεταπτυχιακή Διατριβή, Σχολή Ηλεκτρονικών Μηχανικών και Μηχανικών Υπολογιστών, Πολυτεχνείο Κρήτης, Χανιά, Ελλάς, 2014https://dspace.library.tuc.gr/handle/123456789/241Scatter radio communication is implemented with very simple, low-power and low-cost front-ends that only consist of a single radio frequency (RF) switch. This work develops a bistatic scatter radio wireless sensor network (WSN) with analog energy-assisted tags that monitor relative humidity percentage (%RH) and consume less than 1 mWatt power. Particularly, the tags em- ploy a capacitance-to-frequency converter, that is implemented with a 555 timer and modulates the capacitance of the HCH-1000 %RH sensor. The frequency-modulated pulses are routed to the tag’s RF front-end which is designed to increase communication range. In order to convert the out- put frequency of the tags to %RH, a transfer function is estimated using careful polynomial surface fitting calibration and including the ambient tem- perature. Frequency division multiple access (FDMA) networking is im- plemented with the utilization of different passive components on each tag. Moreover the receiver that is implemented on a software defined radio (SDR) platform exploits carefully designed software filters based on histogram and Savitsky-Golay smoothing techniques. The achieved communication range is over 130 meters at an end-to-end root mean squared error (RMSE) of less than 5 %RH. For the network evaluation, a testbed is calibrated and deployed in a tomato greenhouse demonstrating a novel analog bistatic scatter radio WSN. Finally, an over the air programmable (OTAP) testbed was developed, employing nodes that utilize both an active radio front-end and scatter radio front-end in order to facilitate remote monitoring and debugging.71 pagesenhttp://creativecommons.org/licenses/by/4.0/Motes (Wireless sensor nodes)Sensor nodes, Wirelesswireless sensor nodesmotes wireless sensor nodessensor nodes wirelessΜεταπτυχιακή Διατριβή